Birds of Conservation Concern 4: the population status of birds in the UK, Channel Islands and Isle of Man

Abstract

This is the fourth review of the status of birds in the UK, Channel Islands and Isle of Man. Using standardised criteria, 244 species were assessed and assigned to the Red, Amber or Green list of conservation concern. The assessment criteria include conservation status at global and European levels and, within the UK, historical decline, trends in population and range, rarity, localised distribution and international importance. The findings are alarming, with 20 species moving on to the Red list and only three leaving it. Three formerly regular breeding species are considered to have ceased breeding in the UK (Temminck's Stint Calidris temminckii, Wryneck Jynx torquilla and European Serin Serinus serinus). Recent survey data have resulted in the Dotterel Charadrius morinellus being one of five upland breeding species that moved from Amber to Red in BoCC4.

Full text

708 © British Birds 108 • December 2015 • 708–746
Birds of Conservation
Concern 4: the population
status of birds in the UK,
Channel Islands and
Isle of Man
Mark Eaton, Nicholas Aebischer, Andy Brown,
Richard Hearn, Leigh Lock, Andy Musgrove,
David Noble, David Stroud and Richard Gregory
Rosemary Powell
Abstract This is the fourth review of the status of birds in the UK, Channel
Islands and Isle of Man. Using standardised criteria, 244 species were assessed and
assigned to the Red, Amber or Green list of conservation concern. The
assessment criteria include conservation status at global and European levels and,
within the UK, historical decline, trends in population and range, rarity, localised
distribution and international importance. The findings are alarming, with 20
species moving on to the Red list and only three leaving it. Three formerly regular
breeding species are considered to have ceased breeding in the UK (Temminck’s
Stint Calidris temminckii, Wryneck Jynx torquilla and European Serin Serinus serinus).
Recent survey data have resulted in the Dotterel Charadrius morinellus being one of five upland
breeding species that moved from Amber to Red in BoCC4.

Introduction
This paper presents the fourth ‘Birds of Con-
servation Concern’ (BoCC) assessment for
birds in the UK. Using a well-established
approach, based on quantitative assessments
against standardised criteria, birds are placed
on ‘Red’, ‘Amber’ or ‘Green’ lists to indicate
the level of conservation concern we have for
them. By using a transparent and standard-
ised approach, based upon the best available
da ta, a nd conduc ted by a mul ti-p artne r
group drawn from relevant organisations in
both statutory and non-governmental
sectors, this is a robust assessment of the
status of all the bird species considered an
established part of the UK’s avifauna. These
lists report on the fortunes of individual
species but also indicate broader changes in
the UK’s biodiversity.
In the last assessment (BoCC3, Eaton et al.
2009), we stated that ‘current pressures on
the global environment are unprecedented,
with widespread and severe threats to habi-
tats and the species within them’, and that
funds for conservation action ‘are limited,
and often the first to be lost in times of eco-
nomic downturn’. Since then, the pressures
on nature on a global scale have increased
(Hoekstra & Wiedmann 2014), and the UK
has suffered a lengthy and severe economic
recessi on. An d, as expec ted , funding for
nature conservation has fallen: public sector
spending on biodiversity in the UK has
decreased substantially from a recent peak in
2008/09, both in real terms and as a propor-
tion of GDP (Defra 2014). As a consequence
of a continuing decline in nature (e.g. Burns
et al. 2013, Defra 2014), increasing pressures,
and decreased resources to tackle these
pressures, the need for effective use of those
resources has never been greater. The first
step to ensure effective use of resources is to
prioritise, and exercises such as BoCC are
essential in this regard, helping us to identify
the species (and through further analysis, the
countries and regions, habitats, and conser-
vation issues) that most urgently require
remedial action.
The red-listing of birds in the UK
stretches back over a quarter of a centur y,
with the first formal assessment being that of
Batten et al. (1990), who listed 117 species in
their Red Data Book. ‘Birds of Conservation
Concern’ first appeared later that decade,
with Gibbons et al. (1996b) publishing the
first ‘traffic light system’ of Red, Amber and
Gre en lists. The two subsequent rev iews,
BoCC 2 (Gregor y e t al. 2002) and B oCC3
(Eaton et al. 2009), have sought to employ
the same approach, although there have been
some chang es in met hod olo g y to refle ct
growing experience and changes in data
availability. Key headlines identified during
these BoCC assessments were:
BoCC1 (1996): 36 species were placed on
the first BoCC Red list, which was instru-
mental in raising the profile of the severe
declines in widespread farmland birds
such as Skylark Alauda arvensis and Corn
Bunting Emberiza calandra, part of prob-
ably the greatest loss of UK biodiversity in
the twentieth century (Aebischer et al.
2000).
BoCC2 (2002): the Red list rose to 40
species, with the addition of a number of
woodland birds such as Lesser Spotted
Woodpec ker Dendrocopos minor and
Willow Tit Poecile montana illustrating the
709British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Some 67 (27.5%) of the UK’s regularly occurring bird species are now on the Red
list. As well as reinforcing existing conservation concerns, such as for birds of
woodland and lowland farmland and for long-distance migrants, this assessment
should heighten concern for other groups. Five upland species, including Eurasian
Curlew Numenius arquata and Dotterel Charadrius morinellus, have moved to the
Red list. Declines in the UK’s internationally important breeding seabird
populations are emphasised here by the Red-listing of Shag Phalacrocorax aristotelis,
Kittiwake Rissa tridactyla and Puffin Fratercula arctica. Yet the effect of well-targeted
conservation action is demonstrated by the recovery of Eurasian Bittern Botaurus
stellaris and European Nightjar Caprimulgus europaeus, with both moving from Red
to Amber.

710
Eaton et al.
British Birds 108 • December 2015 • 708–746
bird declines in this habitat (Fuller et al.
2005). The continuing recovery of raptors
such as Red Kite Milvus milvus, Osprey
Pandion haliaetus a nd Mar sh Har r ier
Circus aeruginosus from historical persecu-
tion saw them move from Red to Amber.
BoCC3 (2009): a more substantial growth
in the Red list saw it expanded to 52
species. The additions to the Red list
included more woodland species, such as
Hawfinch Coccothraustes coccothraustes
and Wood Warbler Phylloscopus sibilatrix,
but for the first time the plight of Afro-
Palearctic migrants, such as Common
Cuckoo Cuculus canorus, rose to the fore,
with particular concern for species that
winter in the humid tropics (e.g. Vickery
et al. 2014). Climate change may have
contributed to such declines, as it may
also have done in the decline of six newly
Red-listed northern species (e.g. Whim-
brel Numen ius pha eopus and Redw ing
Turdus iliacus), for which the UK lies at
th e souther n or weste r n edge o f t h e
breeding range. Some comfort could be
gained from the fact that targeted conser-
vation action for Stone-curlew Burhinus
oedicnemus and Woodlark Lullula arborea
resulted in those two species moving from
Red to Amber. Notably, BoCC3 conducted
the first subspecies-le vel BoCC assess-
ment, enabling different levels of concern
to be applied to different races of the same
species (such as Black-tailed Godwits
Limosa limosa of the nominate race and
L. l. islandica), and the threats facing some
of the UK’s endemic races to be identified.
This latest report comes six years after
BoCC3. The six-year gap fits into an emerging
cycle of reporting on the status of the UK’s
birds, influenced by the requirements of the
EU’s Wild Birds Directive (79/409/EEC). This
dictates that all EU Member States report on
the status (e.g. trends, ranges and popula-
tions) of all native bird species at six-year
intervals. This was most recently done in
2013. The collation of similar data from
across the EU, combined with parallel sub-
missions from BirdLife International partners
in non-EU countries, enables Europe-wide
reporting (European Commission 2015) and
the production of an updated European Red
List of Birds (ERLOB; BirdLife International
2015) at regul ar int erva ls. T hro ugh thi s
schedule, a number of the ‘building blocks’ of
BoCC assessments are put in place: updated
Global and European Red List assessments,
and new population estimates through the
work of the Avian Population Estimates Panel
(APEP; see Musgrove et al. 2013), which help
us to assess species against criteria for rarity
and international importance (see below),
the latter helped by the availability of the
European dataset compiled for ERLOB.
416. The Grey Wagtail Motacilla cinerea is one of five upland species moving from Amber to Red in
BoCC4, a move that highlights concern about species of our upland streams and rivers.
Edmund Fellowes/BTO

Methods
The species list
As in previous assessments, we considered all
naturally occurring native species on the
British List (BOU 2013; see also
www.bou.org.uk), but with filters to exclude
some species from the full assessment:
vagrants, defined as species considered by
BBRC (www.bbrc.org.uk), and species occur-
ring only as scarce migrants (e.g. White &
Keh oe 201 5a, b). As before, we have als o
in c luded Gl o bally Th reate n e d specie s
(BirdLife International 2015) that have
occurred in the UK in each of the last 25
years (Balearic Shearwater Puffinus maure-
tanicus and Aquatic Warbler Acrocephalus
paludicola), regardless of scarcity in the UK.
A number of non-native species are well
established in the UK but, despite the fact
that some are appreciated by birdwatchers
and the public, we do not consider these
species to have conservation value in the UK
and they are excluded from this assessment.
As in BoCC3, rarer breeding species were
considered only if they had been proven (or
strongly suspected) to breed for five consecu-
tive years within the most recent 25 years for
which data are available. This excluded a
number of species, such as European Bee-
eater Merops apiaster, which remain occa-
sional breeders in the UK, and others that
may well be in the process of establishing
(e.g. Great White Egret Ardea alba and Little
Bittern Ixobrychus minutus). Species consid-
ered to be regular breeders in BoCC3 were
excluded from consideration (and placed on
the list of ‘former breeders’) if they had not
bred in any of the five most recent years for
which data are available.
Note that some species were excluded
from assessment as breeding species, but
were assessed because they have larger or
better-established non-breeding populations
(e.g. Red-necked Grebe Podiceps grisegena
and Black Tern Chlidonias niger).
One species was added to our list: Caspian
Gull Larus cachinnans was assessed for the
first time since its acceptance as a full species
in 2007 (BOU 2008). Since the last review it
has become apparent that the Caspian Gull is
a regular non-breeding visitor to the UK.
The assessment process
BoCC assessments use a set of quantitative
criteria that fall into two groups, for the Red
and the Amber lists. All species are assessed
against all of these criteria, and are placed on
the highest priority list for which they
qualify. If they meet none of these criteria,
they are placed on the Green list.
The criteria used for BoCC4 were largely
those used for B oCC3, which in turn had
evolved from previous BoCC assessments.
The clear advantage to maintaining a consis-
tent approach to assessments over time is
that it allows a direct comparison of the
results of those assessments. A few minor
adjustmen ts were nece ssary, to allow for
changing circumstances and data availability,
and these are outlined below. All the BoCC
criteria are summarised briefly, but Eaton et
al. (2009) contained further details, while a
fuller account of the criteria and data used
is available in the Supplementary Online
Ma terial at www.britishbirds.co.uk/
wp-content/uploads/2014/07/SM.pdf The
adjustments arose because we felt that the
criteria used for assessing recovery (and any
lapse in that recovery) from historical decline
co uld be improved; bec a use of cha nges
forced upon us by the availability of informa-
tion on European status; and because of the
availability of new atlas data for assessing
non-breeding range change. Our adjustments
and the reasoning behind them are discussed
below, and the impacts of these changes are
analysed in the Results section.
Red-list criteria
IUCN:Global conservation status. Species
that are Globally Threatened (Critically
Endangered, Endangered and Vulnerable, but
not Near Threatened) under IUCN guide-
lines, as assessed by BirdLife International,
the IUCN Red List Authority for birds, in
2015 (www.iucnredlist.org).
HD:Historical decline in breeding popula-
ti o n s. Specie s jud g e d to ha ve decline d
severely between 1800 and 1995, from an
assessment conducted by Gibbons et al.
(1996a), and which have not recovered sub-
sequentl y. The process by which specie s
should be deeme d to have shown partial
recovery from historical decline (hence move
711British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4

712
Eaton et al.
British Birds 108 • December 2015 • 708–746
to the Amber list), or complete re covery
(move to the Green list), or subsequently fal-
tered from those recoveries, was a subject of
much debate. We agreed that the initial
assessments of historical decline by Gibbons
et al., based on a semi-quantitative scoring of
population changes within five periods, were
robust; and that it was still appropriate that
any HD species doubling its population size
or more within the relevant 25-year period,
and exceeding 100 breeding pairs, should
move to the Amber list (provided it did not
qualify as Red under other criteria). We made
one change to this step to be consistent with
other criteria, and introduced an assessment
of trend over the longer-term period, defined
as the entire period used for assessments
since the first BoCC review, starting in 1969.
A key concern, however, was how to treat
change s subse quent to a move to Amber
(HDrec), namely how any future recovery or
decline should be regarded. The criterion
used for BoCC3 stipulated that a decline of
20% between BoCC reviews should dictate
that a species returns to the Red list, whereas
a further increase of 20% over a similar
period would enable a species to move to the
Green list (unless it qualified as Amber under
any other criteria). We felt that this was a
rather unsatisfactory approach, in that in
both cases the criterion used a non-standard
measurement period unrelated to those used
for other BoCC criteria, and which could lead
to changes in status due to relatively insub-
stantial and short-term fluctuations in popu-
lation size.
Therefore, for BoCC4 we have used the
following rationale: a species should be
moved to the Green list (if not qualifying
against other Red or Amber criteria) if it
shows continued and substantial recovery
from historic al declin e beyond the level
(HDrec) that qualified the species for the
Amber list . When it moves to Green, th e
species should be considered as having recov-
ered permanently and would no longer be
considered against the historical decline cri-
terion, i.e. any subsequent decline would be
assessed only against the relevant decline cri-
teria such as BDp (see below). That being the
case, we felt that at least another doubling of
numbers should be required to permit move-
me n t t o t h e G reen list . In f act, we now
require a species to have shown a further
417. One of the headline birds of this current BoCC review is the Eurasian Curlew Numenius
arquata, which moved from Amber to Red. A recent paper in BB called this species the most
important bird conservation priority in the UK (Brown et al. 2015).
Richard Chandler

increase of at least 167% from its HDrec level
in o rder to move to the Green lis t. This
higher threshold ensures that if a species sub-
sequently declines by anything less than 25%
(thus does not trigger a return to the Amber
list under the moderate decline criterion), it
will still remain at more than double its
HDrec numbers.
As an example, imagine a hypothetical
species that qualified for the BoCC1 Red list
under the historical decline criterion, but no
others. This species increased from 100 to
300 pairs within 25 years (well over the dou-
bling to 200 required) and thus was moved
from Red to Amber in BoCC2. If, by the time
of this current review, it had increased to 900
pairs (an increase of 200% from its HDrec
level of 300 pairs and thus above the 167%
threshold of 801 pairs), it would be moved to
the Green list and the HD criterion would no
longer apply. If it had failed to increase by
this rate, but remained above 200 pairs, it
would stay on the Amber list. Finally, if it had
declined to below 200 pairs, it would return
to the Red list. In the last two cases, the HD
criterion would still play a role in future
assessments.
BDp:Breeding population decline. Severe
decline in the UK breeding population size
(>50%) over 25 years (BDp¹) or the longer-
term (BDp²), defined as the entire period
used for assessments since the first BoCC
review, starting in 1969.
WDp:Non-breeding popu latio n decline.
Severe decline in the UK non-breeding popu-
lation size (>50%) over 25 years (WDp¹) or
the longer-term (WDp²) as defined above.
Non-breeding trends were assessed only if a
species has substantially independent
breeding and non-breeding populations, oth-
erwise only the breeding population was
assessed. The same was true for other criteria
which could be applied to both breeding and
non-breeding populations.
BDr:Breeding range decline. Severe decline
in UK range (>50%) between the breeding
bird atlases in 1988–91 and 2007–11 (BDr¹)
or 1968–71 and 2007–11 (BDr²), as meas-
ured by the calculated change in the number
of occupied 10-km squares.
WDr:Non-breeding range decline. Severe
decline in UK range (>50%) between the
wintering bird atlases in 1981–84 and 2007–
11 (WDr¹), as measured by the calculated
change in the number of occupied 10-km
squares. Since there are only two wintering
bird atlases, it was not possible to measure
range change over a longer time period. Note
that while BoCC re view s hav e al ways
intended to assess range change in the non-
breeding season, this is the first assessment
able to do so.
Amber-list criteria
ERLOB:European Red List status. Previous
BoCC assessments have used Species of Euro-
pean Conservation Concern assessments
(SPECs; see Tucker & Heath 1994 and
BirdLife International 2004) as an indication
of wider regional concern for a species, and
thus Amber-listed any UK species that was
SPEC-listed. Although a new assessment of
species status across Europe, the European
Red List of Birds (ERLOB; BirdLife Interna-
tional 2015), was published in 2015, this pro-
duced only IUCN Red List assessments of
regional extinction risk (IUCN 2012) with no
consideration of the wider suite of measures
(species rarity, localisation, moderate decline
and depletion) included in SPEC assess-
ments. At present, it is not clear when or if
new SPECs will be published. Therefore, to
complete the BoCC assessment, we faced a
quandary: to delay publication of BoCC in
the hope that SPEC assessments would be
completed or to drop the use of SPECs as
part of BoCC. We chose the latter option, and
thus have Amber-listed any species on the
European Red List (Critically Endangered,
Endangered or Vulner able). We recognise
that the exclusion of species that were previ-
ously SPEC-listed has had an impact on our
final lists, by moving species from Amber to
Green – and we investigate the scale of this
impact below – but we feel that our decision
provides a sound basis for this and future
BoCC assessments.
HDrec:Histor ica l decline – recover y. As
described above, previously Red-listed for
historical decline, followed by an increase of
at least 100% over 25 years or the longer-
term period. This also applies if the move to
713British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4

HDrec happened in a previous BoCC assess-
ment, having remained above the 100%
increase threshold, but not having recovered
further to move to Green (see text under his-
torical decline above).
BDMp:Breeding population decline. As for
Red-list criterion BDp, but with moderate
decline (>25% but <50%) over 25 years
(BDMp¹) or the longer-term p eriod
(BDMp²).
WDMp:Non-breeding population decline.
As for Red-list criterion WDp, but with mod-
erate decline (>25% but <50%) over 25 years
(WDMp¹) or the longe r-ter m per iod
(WDMp²).
BDMr:Breeding range decline. As for Red-
list criterion BDr, but with moderate decline
(>25% but <50%) between 1988–91 and
2007–11 (BDMr¹) or 1968–71 and 2007–11
(BDMr²).
WDMr:Non-breeding range decline. As for
Red-list criterion WDr, but with moderate
decline (>25% but <50%) between 1981–84
and 2007–11 (WDMr¹).
BR & WR:Breeding and non-breeding rarity.
Species qualified as rare breeders (BR) if the
UK breeding population was <300 pairs, and
as rare non-breeders (WR) if the UK non-
breeding population was <900 individuals.
BL & WL:Breeding and non-breeding localisa-
tion. Species were considered localised if more
than 50% of the UK population was found at
ten or fewer sites in either the breeding (BL) or
the non-breeding (WL) season. Sites were
defined as either Special Protection Areas
(SPAs; Stroud et al. 2001) or Important Bird
Areas (IBAs; Heath & Evans 2000). Rare
breeders or rare non-breeders (see above) were
not assessed against this criterion, as their
small population sizes predispose them to be
restricted to a small number of sites.
BI & WI:Breeding and non-breeding inter-
national importance. Species were considered
of international importance if the UK holds
at least 20% of the European population in
either the breeding (BI) or the non-breeding
(WI) season. European estimates were
derived from data collated as part of the
ERLOB assessment, but for non-breeding
waterbirds we used estimates for the flyway
populations for northwest Europe (wildfowl)
or East Atlantic (waders) (Wetlands Interna-
tional 2015).
Data sources
We are fortunate in that, thanks to the efforts
of thousands of dedicated volunteer bird-
watchers working in tandem with profes-
sional research and conservation
organisations, birds in the UK are one of the
best-monitored taxonomic groups anywhere
in the world. We are thus well equipped to
make status assessments such as BoCC, and
for many species can make robust assess-
ments against all the BoCC criteria. This is
not true for all species, however, and it is
highly likely that some data gaps have influ-
enced our assessment. The principal sources
of data were as for BoCC3, and our treatment
of data from these sources was as described
in Eaton et al. (2009). Further details can be
found at www.britishbirds.co.uk/wp-content/
uploads/2014/07/SM.pdf
In summary, the main sources for meas-
uring population trends were:
The BTO/JNC C Common Birds Census
(CBC) and BTO/JNCC/RSPB Breeding
Bird Survey (BBS); when combined, these
gave us trends for common and w ide-
spread breeding birds from the late 1960s
onwards . Fo r s ome speci e s , su c h as
Co m mon Swift Apu s apu s an d Wood
Warbler, trends were available only from
the start of the BBS in 1994. Details of the
BBS and the latest results can be found in
Harris et al. (2015) and at www.bto.org/
volunteer-surveys/bbs
BTO/JNC C/RSP B Wetland Bird Surve y
(WeBS) and WWT/JNCC/SNH Goose and
Swan Monitoring Programme, wh i ch
together provided annual trends for most
wildfowl species from 1966/67 onwards
and for waders from 1974/75 onwards,
with a few other waterbird species moni-
tored over shorter periods. See Holt et al.
(2015) and www.bto.org/volunteer-
surveys/webs and http://monitoring.wwt.
org.uk/our-work/goose-swan-monitoring-
programme
714
Eaton et al.
British Birds 108 • December 2015 • 708–746

Se a b ird monito r i n g c omes from two
sources: the three complete censuses con-
ducted in 1969–70 (Cramp et al. 1974),
1985–88 (Lloyd et al. 1991) and 1998–
2001 (Mitchell et al. 2004), and the
Seabird Monitoring Programme that has
monitored a UK-wide sample of colonies
since 1986. See www.jncc.defra.gov.uk/
page-1550
Rare Breeding Birds Panel data provided
tr e nds since 1 9 7 3 for rare b r eeders
(defined, loosely, as species with UK pop-
ulations of less than 2,000 pairs, although
data collation for less rare species began
more recently than 1973). We used data
up to 2012 (Holling et al. 2014) to create
long-term and 25-year trends, sometimes
in combination with estimates from
sing le-species surveys. See www.rbbp.
org.uk
Periodic species surveys run under the
Statutory Conservation Agency and RSPB
An n ual Bree d i n g Birds Sc h eme
(SCARABBS) programme, BTO species
surveys and the GWCT/BTO Woodcock
survey provided trends and population
figures for a number of scarce and rare
species.
With occasional exceptions (see the Sup-
plementary Online Material for details),
trends were calculated using data up to and
including 2012. In the case of BBS/CBC and
BBS trends, these were smoothed trends,
using data from 2013 but changes reported
up to 2012 following standard statistical
practice.
For measuring trends in range we relied
on the three breeding bird atlases (Sharrock
1976, Gibbons et al. 1993 and Balmer et al.
2013) and two wintering bird atlases (Lack
1986 and Balmer et al. 2013). Given the 20-
year gaps between breeding atlases, some
BoCC assessments (e.g. BoCC3) have been
forced to rely on rather out-of-date measures
of change in range. The recent Bird Atlas
2007–11 allowed us to generate up-to-date
measures of change in breeding range over
both the long-term (between the first and
third atlases, a period of 40 years) and a 20-
year period (between the second and third
atlases, approximating to the 25-year trend
period). In addition, we were able for the first
time to calculate (near) 25-year trends in
non-breeding range, based on the two winter
at lases with fie l dwor k per i ods cov ering
1981/82 to 1984/85 and 2007/08 to 2010/11.
715British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
418. Three breeding seabirds moved from Amber to Red in BoCC4, with both Shag Phalacrocorax
aristotelis (illustrated) and Kittiwake Rissa tridactyla doing so because of continuing serious declines
in the UK breeding populations.
Andy Hay/RSPB-images

Population estimates were derived from a
range of sources and almost all are as
reported by APEP (see Musgrove et al. 2013).
To maintain consistency with the data used
for UK reporting under the Wild Birds Direc-
tive, we did not update these estimates to
account for any additional data available
since their publication, except for species for
which the results from new national surveys
were availa ble (e. g. Dot ter el Charadrius
morinellus; Hayhow et al. 2015). Localisation
estimates were derived using these UK esti-
mates and data collated in the third review of
the UK’s network of SPAs (Stroud et al. in
prep.). There has been no update of the pop-
ulation estimates within IBAs since the
BoCC3 review; since these form an important
complementary approach to assessing locali-
sation within SPAs, we simply reused the
existing BoCC3 assessments for IBAs.
Race-level assessments
As with BoCC3, we conducted a parallel
assessment of the BoCC status of regularly
occurring races of birds. With the exception
of the changes in criteria (HD and ERLOB)
described above and applied similarly to
races, the process was as described in Eaton et
al. (2009). As before, the lack of some data
sources at a race level (e.g. Global and Euro-
pean IUCN assessments, and monitoring
data at the race level) required us to create
new estimates of populations, trends and
status outside of the UK as best we could
with existing data sources.
We note that over the last six years little
has changed to clarify further the status of
some of the UK’s less well-known races. We
used as our starting point the same list of
races compiled for BoCC3, based primarily on
the list of races maintained by the BOU but
informed by other key references; as before,
our inclusion of a race in this review does not
constitute a judgement on its validity. There
were, however, some rele vant taxo nomic
changes, most arising from investigations at
the species level leading to changes in what is
considered a valid race. Four races were no
longer considered: Pintail Anas acuta and
Sandwich Tern Sterna sandvicensis are now
considered monotypic following the split of
other races into separate species (Southern
Pintail A. eatoni and Cabot’s Tern S. acu-
flavida, respectively), Red Kite is effectively
monotypic following the extinction of the
Cape Verde Kite M. m. fasciicauda (Johnson et
al. 2005), and the occurrence of the Marsh Tit
race Poecile p. palustris in the UK was dis-
missed by Broughton (2009). We considered
three additional races: Greater Scaup Aythya
m. marila, European Storm-petrel Hydrobates
p. pelagicus and Slavonian Grebe Podiceps a.
auritus, as a consequence of these species
being recognised as polytypic since our last
assessment (del Hoyo & Collar 2014).
Results
BoCC4 species-level assessment
Three species were identified as not having
bred in the UK in the last five years for which
data were available; they were thus removed
from the assessment and are now considered
to be ‘former breeders’: Temminck’s Stint
Calidris temminckii, Wryneck Jynx torquilla
and European Serin Serinus serinus (table 1).
The addition of Caspian Gull meant that in
total 244 species were assessed. Of these 244
species, BoCC4 placed 67 (27.5%) on the Red
list, 96 (39.3%) on the Amber list, and 81
(33.2%) on the Green list. Lists of species,
qualifying criteria and values are given in
tables 2–4.
There has been a substantial change in the
way species are distributed among the three
716
Eaton et al.
British Birds 108 • December 2015 • 708–746
Table 1. Formerly regular breeding species in the UK.
year of last recorded breeding
Great Bustard Otis tarda c. 1833
Kentish Plover Charadrius alexandrinus 1979
Temminck’s Stint Calidris temminckii 1993
Black Tern Chlidonias niger 1975
Great Auk Pinguinus impennis c. 1812
Snowy Owl Bubo scandiacus 1975
Wryneck Jynx torquilla 2002
European Serin Serinus serinus 2006

717British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Table 2. Species on the BoCC4 Red list, the criteria under which they qualify, and values for those criteria. Redband Amberccriteria
BoCC3a
IUCN
HD
BDp¹ & BDMp¹
BDp² & BDMp²
WDp¹ & WDMp¹
WDp² & WDMp²
BDr¹ & BDMr¹
BDr² & BDMr²
WDr¹ & WDMr¹
ERLOB
HDrec
BR
WR
BL
WL
BI
WI
White-fronted Goose Anser albifrons G -60 -54
Common Pochard Aythya ferina A VU -51 -34 -38 -36 VU
Greater Scaup Aythya marila R -49 -83 VU 90–100IBA
Long-tailed Duck Clangula hyemalis G VU VU
Common Scoter Melanitta nigra R -63 -81 -58 -50 52 90–100Both
Velvet Scoter Melanitta fusca A VU VU 90–100IBA
Black Grouse Tetrao tetrix R * -80 Severe decline -28
Capercaillie Tetrao urogallus R -42 Severe decline -72 -55
Grey Partridge Perdix perdix R -76 -91 -40
Balearic Shearwater Puffinus mauretanicus R CR CR
Shag Phalacrocorax aristotelis A -62 -36 50–60
Red-necked Grebe Podiceps grisegena A -72 57
Slavonian Grebe Podiceps auritus A VU -56 -62 -33 30
White-tailed Eagle Haliaeetus albicilla R * 37–44
Hen Harrier Circus cyaneus R *
Corn Crake Crex crex R -52 -74 *
Northern Lapwing Vanellus vanellus R -57 -63 VU
Ringed Plover Charadrius hiaticula A -37 -52 -42 50–60
Dotterel Charadrius morinellus A -57 70–80Both
Whimbrel Numenius phaeopus R -67 -50 -27
Eurasian Curlew Numenius arquata A -49 -62 VU 20–30
Black-tailed Godwit Limosa limosa R * -35 VU 61–66 90–100IBA
Ruff Calidris pugnax R -41 -62 -62 0–11 820
Red-necked Phalarope Phalaropus lobatus R * 20–24
Woodcock Scolopax rusticola A -29 -31 -52
Arctic Skua Stercorarius parasiticus R -79 -44
Puffin Fratercula arctica A VU -27 EN 80–90Both
Roseate Tern Sterna dougallii R -73 -86 -27 -62 89

718
Eaton et al.
British Birds 108 • December 2015 • 708–746
Table 2. Species on the BoCC4 Red list, the criteria under which they qualify, and values for those criteria. Redband Amberccriteria (cont.)
BoCC3a
IUCN
HD
BDp¹ & BDMp¹
BDp² & BDMp²
WDp¹ & WDMp¹
WDp² & WDMp²
BDr¹ & BDMr¹
BDr² & BDMr²
WDr¹ & WDMr¹
ERLOB
HDrec
BR
WR
BL
WL
BI
WI
Kittiwake Rissa tridactyla A -74 -62 VU
Herring Gull Larus argentatus R -60 -53 to -60 20–30
Turtle Dove Streptopelia turtur R VU -92 -96 -35 -51 VU
Common Cuckoo Cuculus canorus R -60 -62
Lesser Spotted Woodpecker R -81 -81 -29 -37
Dendrocopos minor
Merlin Falco columbarius A *
Golden Oriole Oriolus oriolus R -81 -70 -40 2–5
Red-backed Shrike Lanius collurio R * -66 -93 -88 1–3
Willow Tit Poecile montana R -91 -94 -49 -54 -43
Marsh Tit Poecile palustris R -43 -72
Skylark Alauda arvensis R -32 -62
Wood Warbler Phylloscopus sibilatrix R -66 -37 -34
Grasshopper Warbler Locustella naevia R -68 -93
Savi’s Warbler Locustella luscinioides R -74 -66 -30 1–3
Aquatic Warbler Acrocephalus paludicola R VU VU
Marsh Warbler Acrocephalus palustris R -77 -88 2–8
Common Starling Sturnus vulgaris R -70 -83
Ring Ouzel Turdus torquatus R -72 -43
Fieldfare Turdus pilaris R -50 -63 -77 -32 1–2
Song Thrush Turdus philomelos R -59
Redwing Turdus iliacus R -73 -49 -45 -32 4–16
Mistle Thrush Turdus viscivorus A -45 -62
Spotted Flycatcher Muscicapa striata R -80 -88
Common Nightingale Luscinia megarhynchos A -60 -85 -43
Pied Flycatcher Ficedula hypoleuca A -53 -27
Black Redstart Phoenicurus ochruros A -52 -33 19–44 400
Whinchat Saxicola rubetra A -55 -38 -48

719British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Table 2. Species on the BoCC4 Red list, the criteria under which they qualify, and values for those criteria. Redband Amberccriteria (cont.)
BoCC3a
IUCN
HD
BDp¹ & BDMp¹
BDp² & BDMp²
WDp¹ & WDMp¹
WDp² & WDMp²
BDr¹ & BDMr¹
BDr² & BDMr²
WDr¹ & WDMr¹
ERLOB
HDrec
BR
WR
BL
WL
BI
WI
House Sparrow Passer domesticus R -32 -66
Tree Sparrow Passer montanus R -90 -37
Yellow Wagtail Motacilla flava R -63 -70 -25 -32
Grey Wagtail Motacilla cinerea A -33 -57
Tree Pipit Anthus trivialis R -64 -70 -29
Hawfinch Coccothraustes coccothraustes R -74 -64 -75
Linnet Linaria cannabina R -60
Twite Linaria flavirostris R * -52
Lesser Redpoll Acanthis cabaret R -64 -83 30–40
Yellowhammer Emberiza citrinella R -49 -54
Cirl Bunting Emberiza cirlus R -85
Corn Bunting Emberiza calandra R * -61 -90 -35 -56 -27
a BoCC3 assessments: R = Red, A = Amber, G = Green
b Red-list criteria:
IUCN: Globally Threatened (CR = Critically Endangered, EN = Endangered, VU = Vulnerable). HD: historical decline in the breeding population. BDp¹/²: severe breeding population
decline over 25 years/longer term. WDp¹/²: severe non-breeding population decline over 25 years/longer term. BDr¹/²: severe breeding range decline over 25 years/longer term. WDr¹:
severe non-breeding range decline over 25 years.
c Amber-list criteria:
ERLOB: Threatened in Europe (CR = Critically Endangered, EN = Endangered, VU = Vulnerable). HDrec: historical decline – recovery. BDMp¹/²: moderate breeding population
decline over 25 years/longer term. WDMp¹/²: moderate non-breeding population decline over 25 years/longer term. BDMr¹/²: moderate breeding range decline over 25 years/longer
term. WDMr¹: moderate non-breeding range decline over 25 years. BR/WR: breeding/non-breeding rarity. BL/WL: breeding/non-breeding localisation. Superscript text indicates
whether species qualified as localised in IBAs, SPAs, or both. BI/WI: breeding/non-breeding international importance. Figures are given in bands for species exceeding the qualifying
thresholds for the localisation and international importance criteria.
Red and Amber criteria for population and range trends are given as % change, and are combined in the same columns (e.g. BDp¹ and BDMp¹): red and amber colour-coding is used to
show which a species qualified against.
When a species has changed list since BoCC3, shading of table cells is used to indicate the criteria responsible for that change.

720
Eaton et al.
British Birds 108 • December 2015 • 708–746
Table 3. Species on the BoCC4 Amber list, the criteria under which they qualify, and values for those criteria. Amber criteriab
BoCC3a
ERLOB
HDrec
BDMp¹
BDMp²
WDMp¹
WDMp²
BDMr¹
BDMr²
WDMr¹
BR
WR
BL
WL
BI
WI
Mute Swan Cygnus olor G 20–30
Bewick’s Swan Cygnus columbianus A EN -45 90–100Both 30–40
Whooper Swan Cygnus cygnus A 9–14 90–100IBA
Bean Goose Anser fabalis A 730
Pink-footed Goose Anser brachyrhynchus A 90–100Both 70–80
Greylag Goose Anser anser A 50–60IBA
Barnacle Goose Branta leucopsis A 70–80Both
Brent Goose Branta bernicla A 70–80Both 40–50
Common Shelduck Tadorna tadorna A -41 50–60IBA 20–30 20–30
Eurasian Wigeon Anas penelope A 50–60IBA 30–40
Gadwall Anas strepera A 20–30
Eurasian Teal Anas crecca A 40–50
Mallard Anas platyrhynchos A -38
Pintail Anas acuta A -34 -27 -27 9–33 90–100IBA 40–50
Garganey Anas querquedula A 14–93
Shoveler Anas clypeata A 30–40
Common Eider Somateria mollissima A VU
Common Goldeneye Bucephala clangula A 200
Smew Mergellus albellus A 180
Common Quail Coturnix coturnix A *
Red Grouse Lagopus lagopus A VU
Black-throated Diver Gavia arctica A 220 560
Great Northern Diver Gavia immer A VU 50–60
Fulmar Fulmarus glacialis A EN 50–60IBA
Manx Shearwater Puffinus puffinus A -28 90–100Both 80–90
European Storm-petrel Hydrobates pelagicus A 90–100Both
Leach’s Storm-petrel Oceanodroma leucorhoa A 90–100Both
Northern Gannet Morus bassanus A 90–100Both 30–40

721British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Table 3. Species on the BoCC4 Amber list, the criteria under which they qualify, and values for those criteria. Amber criteriab(cont.)
BoCC3a
ERLOB
HD rec
BDMp¹
BDMp²
WDMp¹
WDMp²
BDMr¹
BDMr²
WDMr¹
BR
WR
BL
WL
BI
WI
Eurasian Bittern Botaurus stellaris R * 80 600
Eurasian Spoonbill Platalea leucorodia A 2 20
Black-necked Grebe Podiceps nigricollis A 32–51 130
Honey-buzzard Pernis apivorus A 33–69
Marsh Harrier Circus aeruginosus A * 50–60SPA
Montagu’s Harrier Circus pygargus A -28 12–16
Osprey Pandion haliaetus A * 200–250
Spotted Crake Porzana porzana A 27
Common Crane Grus grus A 9–14 52
Stone-curlew Burhinus oedicnemus A -42 70–80Both
Avocet Recurvirostra avosetta A 90–100Both/90–100Both
Oystercatcher Haematopus ostralegus A VU 50–60Both 30–40 30–40
Grey Plover Pluvialis squatarola A 60–70Both 20–30
Bar-tailed Godwit Limosa lapponica A 80–90Both 30–40
Turnstone Arenaria interpres A -41 20–30
Red Knot Calidris canutus A 90–100Both 40–50
Curlew Sandpiper Calidris ferruginea G VU
Sanderling Calidris alba G 60–70SPA
Dunlin Calidris alpina R -49 -27 70–80Both/50–60SPA
Purple Sandpiper Calidris maritima A -43 -49 -33 1
Common Sandpiper Actitis hypoleucos A -45 -40
Green Sandpiper Tringa ochropus A 1–3
Spotted Redshank Tringa erythropus A 98
Greenshank Tringa nebularia G 70–80SPA
Wood Sandpiper Tringa glareola A 11–27 <900
Common Redshank Tringa totanus A -44 -32 -35 -43 20–30
Common Snipe Gallinago gallinago A -31
Great Skua Stercorarius skua A 70–80SPA 50–60

722
Eaton et al.
British Birds 108 • December 2015 • 708–746
Table 3. Species on the BoCC4 Amber list, the criteria under which they qualify, and values for those criteria. Amber criteriab(cont.)
BoCC3a
ERLOB
HDrec
BDMp¹
BDMp²
WDMp¹
WDMp²
BDMr¹
BDMr²
WDMr¹
BR
WR
BL
WL
BI
WI
Black Guillemot Cepphus grylle A -29
Razorbill Alca torda A 70–80Both 20–30
Common Guillemot Uria aalge A 50–60IBA 50–60
Little Tern Sternula albifrons A -30 60–70Both
Sandwich Tern Sterna sandvicensis A -25 90–100Both
Common Tern Sterna hirundo A 60–70IBA
Arctic Tern Sterna paradisaea A -38 -29
Black-headed Gull Chroicocephalus ridibundus A -33 to -41 60–70
Mediterranean Gull Larus melanocephalus A 50–60IBA
Common Gull Larus canus A 40–50
Caspian Gull Larus cachinnans NA 90
Lesser Black-backed Gull Larus fuscus A 70–80IBA 20–30
Glaucous Gull Larus hyperboreus A 170
Iceland Gull Larus glaucoides A 240
Yellow-legged Gull Larus michahellis A 1
Great Black-backed Gull Larus marinus A -29 -33 to -58
Stock Dove Columba oenas A 20–30
Tawny Owl Strix aluco G -31 -30
Short-eared Owl Asio flammeus A -38 -47
European Nightjar Caprimulgus europaeus R -45
Common Swift Apus apus A -38
Common Kingfisher Alcedo atthis A VU
Common Kestrel Falco tinnunculus A -33 -46
Shore Lark Eremophila alpestris A 74
House Martin Delichon urbicum A -33 -49
Willow Warbler Phylloscopus trochilus A -32 -38
Dartford Warbler Sylvia undata A * 50–60SPA
Short-toed Treecreeper Certhia brachydactyla A <300

723British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Table 3. Species on the BoCC4 Amber list, the criteria under which they qualify, and values for those criteria. Amber criteriab(cont.)
BoCC3a
ERLOB
HDrec
BDMp¹
BDMp²
WDMp¹
WDMp²
BDMr¹
BDMr²
WDMr¹
BR
WR
BL
WL
BI
WI
Dipper Cinclus cinclus G -27
Common Redstart Phoenicurus phoenicurus A -31
Dunnock Prunella modularis A -31
Meadow Pipit Anthus pratensis A -44
Water Pipit Anthus spinoletta A 190
Bullfinch Pyrrhula pyrrhula A -39
Common Redpoll Acanthis flammea G 310
Scottish Crossbill Loxia scotica A 100
Parrot Crossbill Loxia pytyopsittacus A 65
Snow Bunting Plectrophenax nivalis A 100
Lapland Bunting Calcarius lapponicus A 710
Reed Bunting Emberiza schoeniclus A -38
a BoCC3 assessments:
NA = Not assessed, R = Red, A = Amber, G = Green
b Amber-list criteria:
ERLOB: Threatened in Europe (CR = Critically Endangered, EN = Endangered, VU = Vulnerable). HDrec: historical decline – recovery. BDMp¹/²: moderate breeding
population decline over 25 years/longer term. WDMp¹/²: moderate non-breeding population decline over 25 years/longer term. BDMr¹/²: moderate breeding range decline
over 25 years/longer term. WDMr¹: moderate non-breeding range decline over 25 years. BR/WR: breeding/non-breeding rarity. BL/WL: breeding/non-breeding localisation.
Superscript text indicates whether species qualified as localised in IBAs, SPAs, or both. BI/WI: breeding/non-breeding international importance. Figures are given in bands
for species exceeding the qualifying thresholds for the localisation and international importance criteria.
When a species has changed list since BoCC3, shading of table cells is used to indicate the criterion/criteria responsible for that change.
Eurasian Bittern moved from Red to Amber since it no longer qualifies under historical decline.

724
Eaton et al.
British Birds 108 • December 2015 • 708–746
Table 4. Species Green-listed by BoCC4.
Name BoCC3a Name BoCC3a
Tufted Duck Aythya fuligula A1 Jackdaw Corvus monedula G
Red-breasted Merganser Mergus serrator G Rook Corvus frugilegus G
Goosander Mergus merganser G Carrion Crow Corvus corone G
Ptarmigan Lagopus muta G Hooded Crow Corvus cornix G
Red-throated Diver Gavia stellata A1 Common Raven Corvus corax G
Great Shearwater Puffinus gravis G Goldcrest Regulus regulus G
Sooty Shearwater Puffinus griseus A1 Firecrest Regulus ignicapilla A6
Great Cormorant Phalacrocorax carbo G Blue Tit Cyanistes caeruleus G
Little Egret Egretta garzetta A2 Great Tit Parus major G
Grey Heron Ardea cinerea G Crested Tit Lophophanes cristatus A1
Little Grebe Tachybaptus ruficollis A3,4 Coal Tit Periparus ater G
Great Crested Grebe Podiceps cristatus G Bearded Tit Panurus biarmicus A7,2
Red Kite Milvus milvus A1 Woodlark Lullula arborea A1,8,2
Northern Goshawk Accipiter gentilis G Sand Martin Riparia riparia A1
Eurasian Sparrowhawk Accipiter nisus G Barn Swallow Hirundo rustica A1
Common Buzzard Buteo buteo G Cetti’s Warbler Cettia cetti G
Golden Eagle Aquila chrysaetos A1 Long-tailed Tit Aegithalos caudatus G
Water Rail Rallus aquaticus G Common Chiffchaff Phylloscopus collybita G
Moorhen Gallinula chloropus G Blackcap Sylvia atricapilla G
Common Coot Fulica atra G Garden Warbler Sylvia borin G
European Golden Plover Pluvialis apricaria A5 Lesser Whitethroat Sylvia curruca G
Little Ringed Plover Charadrius dubius G Common Whitethroat Sylvia communis A4
Little Stint Calidris minuta G Sedge Warbler Acrocephalus schoenobaenus G
Jack Snipe Lymnocryptes minimus A1 Reed Warbler Acrocephalus scirpaceus G
Pomarine Skua Stercorarius pomarinus G Waxwing Bombycilla garrulus G
Long-tailed Skua Stercorarius longicaudus G Eurasian Nuthatch Sitta europaea G
Little Auk Alle alle G Eurasian Treecreeper Certhia familiaris G
Black Tern Chlidonias niger A1 Wren Troglodytes troglodytes G
Little Gull Hydrocoloeus minutus A1 Blackbird Turdus merula G
Rock Dove Columba livia G Robin Erithacus rubecula G
Wood Pigeon Columba palumbus G European Stonechat Saxicola rubicola G
Collared Dove Streptopelia decaocto G Northern Wheatear Oenanthe oenanthe A1
Barn Owl Tyto alba A1 Pied Wagtail Motacilla alba G
Long-eared Owl Asio otus G Rock Pipit Anthus petrosus G
Green Woodpecker Picus viridis A1 Brambling Fringilla montifringilla G
Great Spotted Woodpecker Dendrocopos major G Common Chaffinch Fringilla coelebs G
Hobby Falco subbuteo G Greenfinch Chloris chloris G
Peregrine Falcon Falco peregrinus G Common Crossbill Loxia curvirostra G
Red-billed Chough Pyrrhocorax pyrrhocorax A1 Goldfinch Carduelis carduelis G
Magpie Pica pica G Siskin Spinus spinus G
Eurasian Jay Garrulus glandarius G
a BoCC3 assessments:
R = Red, A = Amber, G = Green. For species which have changed list since BoCC3 (all of which have
moved from the Amber list), the superscript text indicates which criteria they no longer qualify for
Amber under. 1= ERLOB (previously SPEC), 2= breeding localisation, 3= moderate breeding
population decline over 25 years, 4= moderate breeding population decline over longer term,
5= non-breeding international importance, 6= breeding rarity, 7= moderate breeding range decline
over 25 years, 8= moderate breeding range decline over longer term.

lists since BoCC3, with 52 species (21% of
those reassessed) changing B oCC status
(table 5). The Red list has increased by 15,
owing to 19 species being Red-listed for the
first time, one species (Merlin Falco colum-
bar ius) returning to the Red list, and five
species leaving the Red list either by moving
to Amber (three species) or the list of former
breeders (two). Of the species Red-listed for
the first time, two moved directly from the
Gr een list: White- f ronte d Go o s e Anser
albifrons on account of the non-breeding
population decline and Long-tailed Duck
Clangula hyemalis as a consequence of being
classified as Globally Threatened.
After a long decline from the nineteenth
century onwards, the Wryneck last bred in the
UK in 2002 and should now be considered a
former breeder. Of the species to have been lost
from the UK in modern times, this is probably
the first that can be described as once having
been common and widespread; it was recorded
breeding in 54 counties between 1875 and
1900 (Holloway 1996). The other two species
to have ceased breeding, Temminck’s Stint and
European Serin, have only ever been known as
extremely rare or occasional breeders here.
The other notable change is the decrease
in the relative length of the Amber list, which
held 126 species in BoCC3 but 96 in BoCC4:
725British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Table 5. Number of species moving between Red, Amber and Green lists since BoCC3.
BoCC4 status
Red Amber Green Not assessed Total
Red 47 3 0 2 52
Amber 18 85 22 1 126
Green 2 7 59 0 68
Not assessed 0 1 0 – 1
Total 67 96 81 3 2471
1Number of species assessed across BoCC3 and BoCC4 combined; BoCC3 assessed 246 species, BoCC4
244 species.
BoCC3
status
419. The Merlin Falco columbarius returns to the Red list after being Amber-listed in BoCC2 and
BoCC3, as its recovery from historical decline has faltered.
Edmund Fellowes/BTO

22 species moved from Amber to Green and
18 to Red, although seven were gained from
the Green list and three from the Red. The
net increase in the length of the Green list, by
14 species, is ostensibly good news and in
some instances due to
genuine improvements
in the status of species,
but see below for a dis-
cussion of the influence
of changes in the assess-
ment process, which has
resulted in an estimated
nine species moving to
the Green list. The only
new species assessed by
BoCC4, Caspian Gull,
went onto the Amb er
list. Table 5 summarises
the movements between
the three lists since
Bo C C 3. Of th e 243
species assessed by both
BoCC3 and BoCC4, 26
(10.7%) moved to a
higher level of conser-
va t i on co n cern and
another 25 (10.3%)
moved to a lower level
of co ncern; th e
remaining 192 species
(79.0%) did not change
status between the two
assessments.
An analysis of the reasons why species
were Red-listed (which Red-list criteria they
met) revealed that breeding population
decline was by far the most important cri -
terion; 50 species (74.6% of the Red list)
qualified owing to declines
over 25 years (12 species),
th e longer ter m (14 ) or
both time periods (24).
Fi g . 1 shows how many
species were listed against
each criterion, and reveals
that a significant number
(21 species, over the two
time periods) qualified for
the Red list under no other
criteria. Only six species
qualified under non-
br e eding pop u l ation
decline, over either time
period.
The availability of new
atlas data (Balmer e t al.
2013) meant that the
726
Eaton et al.
British Birds 108 • December 2015 • 708–746
IUCN HD BDp1 BDp2 WDp1 WDp2 BDr1 BDr2 WDr1
Red-list criteria
Fig. 1. Criteria under which species qualified for the BoCC4 Red list.
Bars show the number of species qualifying against each Red-list
criterion: blue sections indicate the number of species which
qualified against no other Red-list criteria, i.e. this criterion was
the sole reason for the Red-listing.
40
35
30
25
20
15
10
5
0
number of species qualifying against criteria
multiple qualifying criteria
only qualifying criterion
420. Once a widespread breeding bird in the UK, the Wryneck Jynx
torquilla is now classed as a former breeder, the last confirmed breeding
record being in 2002. British birdwatchers can now expect to see it only
as a spring and autumn passage migrant.
Roger Riddington

range-change criterion increased in impor-
tance in this review. Whereas BoCC3 listed
only five species against severe range decline
(all over the longer-term period), BoCC4
found that 14 species showed a severe decline
in range over at least one of the time periods
and, notably, two species (Woodcock Scolopax
rusticola and Cirl Bunting Emberiza cirlus)
were Red-listed owing to range decline alone.
Fi n ally, a co n cern i ng trend is the
increasing number of the UK’s species which
are considered Globally Threatened. Whereas
previous BoCC assessments have listed only
two species, Balearic Shearwater and Aquatic
Warbler, because of global threat, BoCC4 lists
an additional six: Common Pochard Aythya
fe r i na, Long-t a iled Du c k, Ve lve t Scote r
Melanitta fusca, Slavoni an Grebe , Puffin
Fratercula arctica and Turtle Dove Streptopelia
turtur. Five of these eight Globally Threatened
species did not qualify for Red-listing under
any other criteria (Pochard, Slavonian Grebe
and Turtle Dove being the exceptions).
The impact of changes in the
assessment process
Although the BoCC4 review has seen a sub-
stantial change in the composition of Red,
Amber and Green lists, as described previ-
ously there were some changes in the way the
review was conducted. We have explored the
likely impact of these changes on our results,
to be confident that the trends in list lengths
are not an artefact of these changes.
We can clearly identify how our changes
in tre atment of recover y fro m his tor ical
decline (criteria HD and HDrec) influence
the B oCC 4 outco me (ta ble 6): if we had
applied the approach used in BoCC3, then
Merlin would have remained Amber-listed,
under the HDrec criterion, rather than
returning to Red as HD. Marsh Harrier and
Osprey were considered to have shown com-
plete recovery from historica l decline by
BoCC3 but under BoCC4 they are no longer
considered to have recovered sufficiently to
meet our new threshold. The change in
assessment process is not responsible for a
change in their BoCC status, however, as both
species are also Amber-listed under addi-
tional criteria. The changes have no effect on
the listing of other HD species.
The availability of wintering range data
from Bird Atlas 2007–11 meant that we were
able to assess non-breeding range change
(WDr¹) across all relevant species for the first
time. Very few species showed substantial
no n -bre e ding range decl i nes; onl y one ,
Capercaillie Tetrao urogallus, declined by
more than 50%, and no species were Red- or
727British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
421. Several results from the current review show the impact of a changing climate, and the
movement of Ringed Plover Charadrius hiaticula from Amber to Red is one example, reflecting
the decreasing number of winter visitors as birds are no longer pushed across to the UK by
cold weather on the Continent
Roger Riddington

Amber-listed on this criterion alone.
The change in how status at the European
level was incorporated (moving from the
SPEC to the ERLOB criterion) has had more
of an impact on our lists, although it affects
only potential listing on the Amber and Green
lists. Some 65 species that qualified under the
SPEC criterion in BoCC3 did not qualify
under ERLOB in the new assessment (only 20
UK species were listed as threatened by
ERLOB), and as a consequence, 15 of these
moved to the Green list (the remaining 50
being retained as Red or Amber through
other criteria). Without having new SPEC
assessments for comparison, it is difficult to
be certain how many of those 15 species
would have been retained on the Amber list if
new SPECs had been available. Additional
analyses conducted on data from EU member
states (BirdLife International 2015) suggest
that, at that scale, six species (e.g. Tufted Duck
Aythya fuligula and Green Woodpecker Picus
viridis) had recovered from the measures of
population decline and/or depletion that
resulted in them being SPEC-listed previ-
ously, and would not have been SPEC-listed if
such assessments had been made. It is less
clear for the remaining nine species, but it
seems likely that most if not all of these
woul d have been re tai ned as S PEC – for
example, Golden Eagle Aquila chrysaetos
would have still qualified as Rare within
Europe (see BirdLife International 2004). It is
also possible that new assessment would have
led to the SPEC-listing of some species for the
first time, and potentially the movement of
these species from the Green list to Amber.
In conclusion, the changes in BoCC4 cri-
teria resulted in one additional species on the
Red list, and approximately nine additional
species on the Green list, compared with the
same criteria used for BoCC3 (table 6).
728
Eaton et al.
British Birds 108 • December 2015 • 708–746
Table 6. The likely impact of the changes of assessment criteria (for historical decline and
European status) on BoCC4 results.
Change in process Effect (BoCC3 list →BoCC4 list) Species affected
Changes in recovery from HD Amber →Red Merlin
Using ERLOB instead of Amber →Green Sooty Shearwater, Golden Eagle,
SPEC status Jack Snipe, Black Tern, Little Gull,
Red-billed Chough, Sand Martin,
Barn Swallow, Northern Wheatear
422. Largely as a result of targeted conservation effort, to create and maintain reedbeds in suitable
condition, the Eurasian Bittern Botaurus stellaris moved from Red to Amber in the current review,
another step on its continued recovery as a breeding species in the UK.
Ben Andrew/RSPB-images

Data gaps
We lacked population trends for 21 breeding
species, including seabird species for which
the UK is internationally important (e.g.
Manx Shearwater Puffinus puffinus), upland
species (e.g. Dunlin Calidris alpina), the
endemic Scottish Crossbill Loxia scotica and a
disparate collection of other species with dis-
tributions, habitat preferences and behav-
iours which mean that they elude the
attentions of standard monitoring pro-
grammes (e.g. Eurasian Wigeon Anas pene-
lope, Long-eared Owl Asio otus and Rock
Pipit Anthus petrosus). These are important
gaps, not least because, as shown in fig. 1, the
criteria for breeding population decline tend
to be by far the most influential in deter-
mining listing status. It is worth noting that
another of this group, the Short-eared Owl
Asio flammeus, showed a long-term decline in
range of 47%; had population monitoring
been undertaken for the same period it is dis-
tinctly possible that it may have qualified for
the Red list. Noting that longer-term
bre eding trends were lackin g for a much
larger number of birds (54 species), however,
does indicate that recent decades have seen a
welcome improvement in our monitoring
coverage.
Race-level assessment
BoCC4 assessments were made for 224 races
(of 173 species) occurring regularly in the
UK. Of these, 57 races (25.4%) were Red-
li ste d, 94 (42. 0%) Amber-lis ted, and 73
(32.6%) Green-listed; these proportions are
similar to those for the species-level assess-
ment. Lists of races on the three lists and the
criteria under which they qualify are given in
tables 7–9.
Eighteen races have moved onto the Red
list since BoCC3: 16 from Amber, and two
newly assessed races (Slavonian Grebe and
Greater Scaup). Many of the moves to the
Red list mirror changes in parent species, for
example because of UK population declines
which apply to the race as well as to the
species, such as for Shag Phalacrocorax a.
aristotelis and Pied Flycatcher Ficedula h.
hypoleuca. However, three of the new Red-
listed races are not Red-listed at species level
(in all, 44 races have a different BoCC4 listing
from their parent species) including, most
no t a bly, the B r itish r ace of Gre e nfinch
Chloris chloris harrisoni – as a species, Green-
finch is Green -li sted but the race would
qualify as Globally Threatened due to recent
decline, driven by outbreaks of the parasitic
disease trichomonosis (Lawson et al. 2012).
729British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
423. The European Nightjar Caprimulgus europaeus moves from Red to Amber in BoCC4, joining
other largely heathland and grassland species, such as Stone-curlew Burhinus oedicnemus and
Woodlark Lullula arborea, which made the same move in the BoCC3 review.
Andy Hay/RSPB-images

730
Eaton et al.
British Birds 108 • December 2015 • 708–746
Ben Hall/RSPB-images
425. The Woodcock Scolopax rusticola moves from Amber to Red in BoCC4 as a consequence of a
shrinking breeding range in the UK. It is one of just two species (Cirl Bunting Emberiza cirlus being
the other) that are Red-listed owing to range decline alone.
Stanley Porter/RSPB-images
424. Common Pochard Aythya ferina has moved from Amber to Red as a consequence of
population decline – not just in the UK, where it has shown a severe drop in non-breeding
numbers, but also more widely. This international decline has resulted in it being listed as
Vulnerable on the IUCN Global Red list.

731British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Table 7. Races on the BoCC4 Red list and the criteria under which they qualify. Redband Amberccriteria
BoCC4 speciesa
IUCN
HD
BDp¹ & BDMp¹
BDp²& BDMp²
WDp¹ & WDMp¹
WDp²& WDMp²
BDr¹ & BDMr¹
BDr²& BDMr²
WDr¹ & WDMr¹
ERLOB
HDrec
BR
WR
BL
WL
BI
WI
‘Taiga Bean Goose’ Anser f. fabalis A * * *
‘Greenland White-fronted Goose’ R * * *
Anser albifrons flavirostris
‘European White-fronted Goose’ R * * *
Anser a. albifrons
*Greater Scaup Aythya m. marila R * * * * *
Common Eider Somateria m. mollissima A * *
Black Grouse Tetrao tetrix britannicus R * * * * * * *
Capercaillie Tetrao u. urogallus R * * * *
Grey Partridge Perdix p. perdix R * * *
*Fulmar Fulmarus g. glacialis A * * *
*Shag Phalacrocorax a. aristotelis R * * *
*Red-necked Grebe Podiceps g. grisegena R * *
*Slavonian Grebe Podiceps a. auritus R * * * *
Hen Harrier Circus c. cyaneus R *
*Ringed Plover Charadrius h. hiaticula R * * * *
Whimbrel Numenius p. phaeopus R * * *
*Eurasian Curlew Numenius a. arquata R * * * * *
Black-tailed Godwit Limosa l. limosa R * * * * *
Roseate Tern Sterna d. dougallii R * * * * *
*Kittiwake Rissa t. tridactyla R * * *
Herring Gull Larus argentatus argenteus R * * * * *
Turtle Dove Streptopelia t. turtur R * * * * * *
Common Cuckoo Cuculus c. canorus R * *
*Common Kingfisher Alcedo atthis ispida A * * *
Lesser Spotted Woodpecker R * * * * * * *
Dendrocopos minor comminutus
*Merlin Falco columbarius aesalon R *
Speciesd/ Race

732
Eaton et al.
British Birds 108 • December 2015 • 708–746
Table 7. Races on the BoCC4 Red list and the criteria under which they qualify. Redband Amberccriteria (cont.)
BoCC4 speciesa
IUCN
HD
BDp¹ & BDMp¹
BDp²& BDMp²
WDp¹ & WDMp¹
WDp²& WDMp²
BDr¹ & BDMr¹
BDr²& BDMr²
WDr¹ & WDMr¹
ERLOB
HDrec
BR
WR
BL
WL
BI
WI
Speciesd/ Race
Golden Oriole Oriolus o. oriolus R * * * *
Red-backed Shrike Lanius c. collurio R * * * * *
Willow Tit Poecile montana kleinschmidti R * * * * * * * *
Marsh Tit Poecile palustris dresseri R * * *
Skylark Alauda a. arvensis R * *
Grasshopper Warbler Locustella n. naevia R * *
Savi’s Warbler Locustella l. luscinioides R * * * *
‘Fair Isle Wren’ G * * * *
Troglodytes troglodytes fridariensis
‘St Kilda Wren’ Troglodytes t. hirtensis G * * * *
Common Starling Sturnus v. vulgaris R * *
Ring Ouzel Turdus t. torquatus R * *
‘Hebridean Song Thrush’ R * * *
Turdus philomelos hebridensis
Song Thrush Turdus p. clarkei R * *
Redwing Turdis i. iliacus R * * * * *
*Mistle Thrush Turdus v. viscivorus R * *
Spotted Flycatcher Muscicapa s. striata R * *
Common Nightingale R * * *
Luscinia m. megarhynchos
*Pied Flycatcher Ficedula h. hypoleuca R * *
*Black Redstart R * * * *
Phoenicurus ochruros gibraltariensis
House Sparrow Passer d. domesticus R * *
Tree Sparrow Passer m. montanus R * *
Yellow Wagtail Motacilla flava flavissima R * * * * * * *
*Grey Wagtail Motacilla c. cinerea R * *
Tree Pipit Anthus t. trivialis R * * *

733British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Table 7. Races on the BoCC4 Red list and the criteria under which they qualify. Redband Amberccriteria (cont.)
BoCC4 speciesa
IUCN
HD
BDp¹ & BDMp¹
BDp²& BDMp²
WDp¹ & WDMp¹
WDp²& WDMp²
BDr¹ & BDMr¹
BDr²& BDMr²
WDr¹ & WDMr¹
ERLOB
HDrec
BR
WR
BL
WL
BI
WI
Hawfinch Coccothraustes c. coccothraustes R * * *
*Greenfinch Chloris chloris harrisoni G * * *
Linnet Linaria c. cannabina R *
Twite Linaria flavirostris bensonorum R * * *
Twite Linaria f. pipilans R * * *
Yellowhammer Emberiza c. citrinella R * *
Corn Bunting Emberiza calandra clanceyi R * * * * * * *
Corn Bunting Emberiza c. calandra R * * * * * *
a BoCC4 assessments for ‘parent’ species: R = Red, A = Amber, G = Green
b Red-list criteria:
IUCN: Globally Threatened. HD: historical decline in the breeding population. BDp¹/²: severe breeding population decline over 25 years/longer term. WDp¹/²: severe
non-breeding population decline over 25 years/longer term. BDr¹/²: severe breeding range decline over 25 years/longer term. WDr¹: severe non-breeding range decline over
25 years.
c Amber-list criteria:
ERLOB: Threatened in Europe. HDrec: historical decline – recovery. BDMp¹/²: moderate breeding population decline over 25 years/longer term. WDMp¹/²: moderate non-
breeding population decline over 25 years/longer term. BDMr¹/²: moderate breeding range decline over 25 years/longer term. WDMr¹: moderate non-breeding range decline
over 25 years. BR/WR: breeding/non-breeding rarity. BL/WL: breeding/non-breeding localisation. BI/WI: breeding/non-breeding international importance.
Red and Amber criteria for population and range trends are combined in the same columns (e.g. BDp¹and BDMp¹): red and amber colour-coding is used to show which a
species qualified against.
d Asterisks indicate species with a changed race-level status since BoCC3.
This table lists Red-listed races of polytypic species only: it does not include monotypic species, e.g. Long-tailed Duck.
Speciesd/ Race

734
Eaton et al.
British Birds 108 • December 2015 • 708–746
Table 8. Races on the BoCC4 Amber list and the criteria under which they qualify.
BoCC4 speciesa
ERLOB
HDrec
BDMp¹
BDMp²
WDMp¹
WDMp²
BDMr¹
WDMr¹
BDMr²
BR
WR
BL
WL
BI
WI
Bewick’s Swan Cygnus columbianus bewickii A * * * *
‘Tundra Bean Goose’ Anser fabalis rossicus A *
Greylag Goose Anser a. anser A * *
*‘Dark-bellied Brent Goose’ Branta b. bernicla A * *
‘Pale-bellied Brent Goose’ Branta b. hrota A * *
Eurasian Teal Anas c. crecca A *
Mallard Anas p. platyrhynchos A *
Common Eider Somateria mollissima faeroeensis A * * *
Common Goldeneye Bucephala c. clangula A *
Common Quail Coturnix c. coturnix A *
Red Grouse Lagopus lagopus scotica A *
Ptarmigan Lagopus muta millaisi G *
Black-throated Diver Gavia a. arctica A * *
European Storm-petrel Hydrobates p. pelagicus A *
Leach’s Storm-petrel Oceanodroma l. leucorhoa A * *
Great Cormorant Phalacrocorax c. carbo G *
Great Cormorant Phalacrocorax carbo sinensis G *
Eurasian Bittern Botaurus s. stellaris A * * *
Eurasian Spoonbill Platalea l. leucorodia A * *
Black-necked Grebe Podiceps n. nigricollis A * *
Marsh Harrier Circus a. aeruginosus A * *
Osprey Pandion h. haliaetus A * *
Common Crane Grus g. grus A * *
*Stone-curlew Burhinus o. oedicnemus A * *
Oystercatcher Haematopus o. ostralegus A * * * *
Black-tailed Godwit Limosa limosa islandica R * * *
Bar-tailed Godwit Limosa l. lapponica A * * *
Turnstone Arenaria i. interpres A * *
Speciesc/ Race

735British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Table 8. Races on the BoCC4 Amber list and the criteria under which they qualify. (cont.)
BoCC4 speciesa
ERLOB
HDrec
BDMp¹
BDMp²
WDMp¹
WDMp²
BDMr¹
WDMr¹
BDMr²
BR
WR
BL
WL
BI
WI
Red Knot Calidris canutus islandica A * *
Dunlin Calidris a. alpina A * * *
*Dunlin Calidris alpina schinzii A * *
Common Redshank Tringa t. totanus A * * * *
Common Redshank Tringa t. robusta A * *
Common Snipe Gallinago g. gallinago A *
Common Snipe Gallinago g. faeroeensis A *
*Black Guillemot Cepphus grylle arcticus A *
Razorbill Alca torda islandica A * *
Common Guillemot Uria a. aalge A *
Common Guillemot Uria a. albionis A * *
Little Tern Sternula a. albifrons A * *
Common Tern Sterna h. hirundo A *
Common Gull Larus c. canus A *
Lesser Black-backed Gull Larus fuscus graellsii A * *
Glaucous Gull Larus h. hyperboreus A *
Iceland Gull Larus g. glaucoides A *
Yellow-legged Gull Larus m. michahellis A *
Stock Dove Columba o. oenas A *
*Tawny Owl Strix aluco sylvatica A * *
Short-eared Owl Asio f. flammeus A * *
European Nightjar Caprimulgus e. europaeus A *
Common Swift Apus a. apus A *
Great Spotted Woodpecker Dendrocopos major anglicus G *
Common Kestrel Falco t. tinnunculus A * *
Merlin Falco columbarius subaesalon R *
Red-billed Chough Pyrrhocorax p. pyrrhocorax G *
Eurasian Jay Garrulus glandarius hibernicus G *
Speciesc/ Race

736
Eaton et al.
British Birds 108 • December 2015 • 708–746
Table 8. Races on the BoCC4 Amber list and the criteria under which they qualify. (cont.)
BoCC4 speciesa
ERLOB
HDrec
BDMp¹
BDMp²
WDMp¹
WDMp²
BDMr¹
WDMr¹
BDMr²
BR
WR
BL
WL
BI
WI
Eurasian Jay Garrulus g. rufitergum G *
Blue Tit Cyanistes caeruleus obscurus G *
Great Tit Parus major newtoni G *
Crested Tit Lophophanes cristatus scoticus G *
Coal Tit Periparus ater britannicus G *
Skylark Alauda arvensis scotica R * *
Shore Lark Eremophila alpestris flava A *
House Martin Delichon u. urbicum A * *
Long-tailed Tit Aegithalos caudatus rosaceus G *
Willow Warbler Phylloscopus t. trochilus A * *
Dartford Warbler Sylvia undata dartfordiensis A * *
Short-toed Treecreeper Certhia brachydactyla megarhyncha A *
‘Hebridean Wren’ Troglodytes troglodytes hebridensis G *
‘Shetland Wren’ Troglodytes t. zetlandicus G *
Wren Troglodytes troglodytes indigenus G *
‘Shetland Starling’ Sturnus vulgaris zetlandicus R *
Dipper Cinclus cinclus gularis A * *
Dipper Cinclus c. hibernicus A *
Common Redstart Phoenicurus p. phoenicurus A *
Dunnock Prunella modularis occidentalis A * *
‘Blue-headed Wagtail’ Motacilla f. flava R * *
‘Grey-headed Wagtail’ Motacilla f. thunbergi R *
Pied Wagtail Motacilla alba yarrellii G *
*‘White Wagtail’ Motacilla a. alba G *
Meadow Pipit Anthus p. pratensis A *
Meadow Pipit Anthus p. whistleri A *
Water Pipit Anthus s. spinoletta A *
Rock Pipit Anthus p. petrosus G *
Speciesc/ Race

737British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Table 8. Races on the BoCC4 Amber list and the criteria under which they qualify. (cont.)
BoCC4 speciesa
ERLOB
HDrec
BDMp¹
BDMp²
WDMp¹
WDMp²
BDMr¹
WDMr¹
BDMr²
BR
WR
BL
WL
BI
WI
Common Chaffinch Fringilla coelebs gengleri G *
Bullfinch Pyrrhula pyrrhula pileata A * *
Linnet Linaria cannabina autochthona R * *
*Common Redpoll Acanthis f. flammea A *
Goldfinch Carduelis carduelis britannica G *
Snow Bunting Plectrophenax n. nivalis A *
Snow Bunting Plectrophenax nivalis insulae A *
Lapland Bunting Calcarius l. lapponicus A *
Lapland Bunting Calcarius l. subcalcaratus A *
Reed Bunting Emberiza s. schoeniclus A *
aBoCC4 assessments for ‘parent’ species: R = Red, A = Amber, G = Green
bAmber-list criteria:
ERLOB: Threatened in Europe. HDrec: historical decline – recovery. BDMp¹/²: moderate breeding population decline over 25 years/longer term. WDMp¹/²: moderate non-
breeding population decline over 25 years/longer term. BDMr¹/²: moderate breeding range decline over 25 years/longer term. WDMr¹: moderate non-breeding range decline
over 25 years. BR/WR: breeding/non-breeding rarity. BL/WL: breeding/non-breeding localisation. BI/WI: breeding/non-breeding international importance.
cAsterisks indicate species with a changed race-level status since BoCC3.
This table lists Amber-listed races of polytypic species only: it does not include monotypic species, e.g. Pink-footed Goose Anser brachyrhynchus.
Speciesc/ Race

738
Eaton et al.
British Birds 108 • December 2015 • 708–746
Discussion
The growing Red list
BoCC4 has placed more species onto the Red
list than ever before. Some 67 species are
Red-listed (27.5% of the species assessed)
and that list has grown by a substantially
larger increment than in any previous BoCC
review (fig. 2). In tot al, 20 spe cies have
mo ved to Red , with only th r e e species
moving from Red to Amber.
The Red list increased substantially
between the second and third BoCC reviews
but a number of those additions were due to
changes to the assessment process. In partic-
ular, the introduction of the longer-term
time window for consideration of population
and range trends resulted in 11 species
moving to (or staying on) the Red list that
would not otherwise have done so. This is
not the case here; only Merlin has returned to
the Red list as a consequence of changes to
the way we treat recover y from historical
decline. The other significant change in our
process is the tre atment of conser vat ion
concern at a European level because we lack a
current SPEC assessment. This has resulted
Table 9. Races on the BoCC4 Green list.
a BoCC4 assessments for ‘parent’ species: R = Red, A = Amber, G = Green.
This table lists Green-listed races of polytypic species only: it does not include monotypic species,
e.g. Brambling Fringilla montifringilla.
Species / Race BoCC4 speciesa
Goosander Mergus m. merganser G
Little Egret Egretta g. garzetta G
Grey Heron Ardea c. cinerea G
Little Grebe Tachybaptus r. ruficollis G
Great Crested Grebe Podiceps c. cristatus G
Northern Goshawk Accipiter g. gentilis G
Eurasian Sparrowhawk Accipiter n. nisus G
Common Buzzard Buteo b. buteo G
Golden Eagle Aquila c. chrysaetos G
Water Rail Rallus a. aquaticus G
Moorhen Gallinula c. chloropus G
Common Coot Fulica a. atra G
Little Ringed Plover Charadrius dubius curonicus G
Ringed Plover Charadrius hiaticula tundrae R
Dunlin Calidris alpina arctica A
Long-tailed Skua Stercorarius l. longicaudus G
Razorbill Alca t. torda A
Little Auk Alle a. alle G
Black Tern Chlidonias n. niger G
Lesser Black-backed Gull Larus fuscus intermedius A
Herring Gull L. a. argentatus R
Rock Dove/Feral Pigeon Columba l. livia G
Wood Pigeon Columba p. palumbus G
Collared Dove Streptopelia d. decaocto G
Barn Owl Tyto a. alba G
Long-eared Owl Asio o. otus G
Green Woodpecker Picus v. viridis G
Hobby Falco s. subbuteo G
Peregrine Falcon Falco p. peregrinus G
Magpie Pica p. pica G
Eurasian Jay Garrulus g. glandarius G
Jackdaw Corvus m. monedula G
Jackdaw Corvus m. spermologus G
Rook Corvus f. frugilegus G
Carrion Crow Corvus c. corone G
Hooded Crow Corvus c. cornix G
Common Raven Corvus c. corax G
Species / Race BoCC4 speciesa
Goldcrest Regulus r. regulus G
Firecrest Regulus i. ignicapilla G
Blue Tit Cyanistes c. caeruleus G
Great Tit Parus m. major G
Coal Tit Periparus a. ater G
Coal Tit Periparus a. hibernicus G
Bearded Tit Panurus b. biarmicus G
Woodlark Lullula a. arborea G
Sand Martin Riparia r. riparia G
Barn Swallow Hirundo r. rustica G
Cetti’s Warbler Cettia c. cetti G
Common Chiffchaff Phylloscopus c. collybita G
Willow Warbler Phylloscopus trochilus acredula A
Blackcap Sylvia a. atricapilla G
Garden Warbler Sylvia b. borin G
Lesser Whitethroat Sylvia c. curruca G
Common Whitethroat Sylvia c. communis G
Reed Warbler Acrocephalus s. scirpaceus G
Waxwing Bombycilla g. garrulus G
Eurasian Nuthatch Sitta europaea caesia G
Eurasian Treecreeper Certhia familiaris britannica G
Wren Troglodytes t. troglodytes G
Blackbird Turdus m. merula G
Song Thrush Turdus p. philomelos R
Redwing Turdus iliacus coburni R
Robin Erithacus r. rubecula G
Robin Erithacus r. melophilus G
European Stonechat Saxicola rubicola hibernans G
Northern Wheatear Oenanthe o. oenanthe G
‘Greenland Wheatear’ Oenanthe o. leucorhoa G
Dunnock Prunella m. modularis A
Dunnock Prunella m. hebridium A
Rock Pipit Anthus petrosus littoralis G
Common Chaffinch Fringilla c. coelebs G
Greenfinch Chloris c. chloris G
Common Crossbill Loxia c. curvirostra G

in a number o f
species that may
ot h e r w i se ha ve
been Amber-listed
being moved to the
Gr een l i s t ; th e
Green list grew by
13 species, of which
nine (or possibly
mo r e) ma y hav e
been Amber-listed
had we been able to
retain the use of
SP E C . Some of
these species con-
tinue to merit con-
servation attention,
including Red-
bi l l e d C h o ugh
P y r r h o c o r a x
pyrrhocorax, which
remains relatively
rare and range-
re s t r icted in t h e
UK; and Golden
Eagle, also relatively rare and range-restricted
in the UK, due to persecution, both historical
and recent (Whitfield et al. 2007).
A priority list such as BoCC4, or a national
IUCN Red List, should not, however, be the
only consideration in decisions on which
species should be the recipients of conserva-
ti o n effor t. As w e ll as B o C C status, we
encourage the consideration of other factors,
such as likelihood of conservation action
being successful, the logistics of such action
and synergies with other conservation activi-
739British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
BoCC1 BoCC2 BoCC3 BoCC4
Fig. 2. Lengths of Red, Amber and Green lists in the four BoCC assessments.
Note that the assessment process has developed over time, with changes in
data availability and criteria between assessments, and a small number of
changes in Red, Amber and Green list lengths have been as a consequence
of these changes.
250
200
150
100
50
0
number of species
Green list
Amber list
Red list
Former breeder
426. The Whinchat Saxicola rubetra moves from Amber to the Red list in BoCC4, and is a member
of two distinct groupings to cause concern – upland species and Afro-Palearctic migrants.
Edmund Fellowes/BTO

740
Eaton et al.
British Birds 108 • December 2015 • 708–746
europaeus (as well as Red Kite moving to the
Green list) in BoCC4 . Simp ly becau se a
species moves from Red to Amber does not,
however, necessarily mean that conservation
effort can be wit hdr aw n immedi ately, as
many remain dependent upon conservation
action. A good example is the Stone-curlew.
A large part of the UK population nests in
arable fields, in which labour-intensive inter-
ventions are required to protect the birds
from agricultural operations; an abrupt ces-
sation of that effort would most likely result
in the Stone-curlew’s return to the Red list.
Work is ongoing to encourage more birds to
nest in semi-natural grasslands or in safe
nesting plots on arable land, supported by
agri-environment schemes, paving the way
for a more sustainable population.
Themes in bird conservation in
the UK, as highlighted by BoCC4
Some consistent themes have emerged from
previous assessments and other overviews of
the status of the UK’s biodiversity (e.g. Burns
et al. 2013), and this review largely
reiterates these. Our overriding
concern is for the ever-increasing
number of species on the Red list:
de s p ite a proven abili t y to
improve the status of species of
concern, the rate at which species
are added to the Red list greatly
exceeds our current ability to take
recovery action. If we believe that
the presence of speci es on Red
lists is an effective barometer of
the state of our wildlife (e.g.
Butchart et al. 2005), then this
review paints a bleak picture.
In addition to the increase in
the number of species on the Red
list, three species have moved to
th e li st of former br e eders.
Although this is loss at a UK
rather than global scale, and while
for highly mobile taxa such as
birds recolonisation can never be
ruled out, these losses should not
be overlo o ked. In p a r t icular,
Wryneck becomes the first once-
widespread species to have been
lost from the UK since the extinc-
ti on of t he Great Bus tard O tis
427. Concerns about the state of the UK’s internationally
important seabird populations is heightened by the BoCC4 review,
with three familiar species moving to the Red list, the Puffin
Fratercula arctica as a result of its IUCN listing as Vulnerable.
Roger Riddington
ties. And while we might expect most Red-
listed species to be the highest priorities for
conservation, there are some on which it
might not be appropriate to expend scarce
conservation resources. These might include
species at the edge of their European range in
the UK, for which the factors that determine
their abundance in the UK may lie elsewhere.
Conversely, there are species on the BoCC
Amber list that have been, and may continue
to be, high priorities for conservation action,
especially ones that might be considered as
conservation dependent. There have been a
number of noteworthy conser vation suc-
cesses in the UK due to the delivery of tar-
geted and well-informed conservation action
for pri orit y bird spe cie s. While many of
these, such as Corn Crake Crex crex and Cirl
Bunting,remain Red-listed, we should cele-
brate the movement of others from Red to
Amber, such as Red Kite and Marsh Harrier
in BoCC2, Stone-curlew and Woodlark in
BoCC3, and Eurasian Bittern Botaurus stel-
laris and European Nightjar Caprimulgus

tarda in around
1833. It is a
sobering thought
that the Wryneck
was once suffi-
ci e n tly c ommon
for the RSPB to sell
nestboxes for it.
That no new
farmland birds
have moved to the
Red list pro b ably
reflects the fact that
the species which
co ntinue t o b e
affected adve rsely
by modern agricul-
tural methods are
already listed there.
Although the
trends of some of these species have levelled
ou t in recent y ears, other s conti n u e to
decline; most alarmingly in the case of Turtle
Dove, which has declined by 13% per annum
since 1995 (Harris et al. 2015). Declines in
woodland specialists (as opposed to general-
ists, which on the whole have been doing
well; Defra 2014) were highlighted in BoCC3,
and this review adds three more woodland
birds, Woodcock, Common Nightingale Lus-
cinia megarhynchos and Pied Flycatcher, to
the Red list. There are now 16 woodland
species on the Red list, more than any other
habitat group, although a higher proportion
of farmland species are Red-listed (fig. 3).
The greatest increases in the proportion of
species Red-listed are for birds breeding in
upland and coastal habitats (five and four
741British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
Fig. 3. Proportion of breeding birds in the Red, Amber and Green lists
by major habitat type (habitat categories follow Gibbons et al. 1993).
Bars show percentages in the Red, Amber and Green lists, figures give the
actual number of species.
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Green
Amber
New (BoCC4)
Red
Existing
(BoCC3) Red
Coastal (31)
Farmland (26)
Lowland
wetland (33)
Upland (37)
Urban (6)
Woodland (49)
Not classified (21)
All (203)
428. Another woodland specialist and long-distance migrant, the Common Nightingale Luscinia
megarhynchos shows such a severe decline in breeding numbers that it is now Red-listed.
Jeff & Allison Kew/BTO

species respectively). The increase in coastal
species chiefly reflects the deteriorating status
of the UK’s seabirds; with the addition of
Kittiwake Rissa tridactyla, Shag and Puffin,
the number of seabirds on the Red list has
nearly doubled. Furthermore, with Razorbill
Alca torda now considered as globally Near
Threatened (BirdLife International 2015),
there is growing concern for our seabirds,
particularly as in global terms they are
among the most important components of
the UK’s avifauna. We should also note that,
with the addition of Velvet Scoter and Long-
tailed Duck, four of the UK’s seaducks are
now on the Red list, although the causes of
their declines may be different from and
possibly unrelated to marine impacts.
The recent Bird Atlas 2007–11 (Balmer et
al. 2013) highlighted two areas of concern
that, arguably, have not before been recog-
nised as being among the UK’s highest con-
servation priorities: declines in the ranges of
both breeding waders and upland breeding
species (and there is, of course, much overlap
between these two groups). BoCC4 lends
support for this view. The addition of five
upland breeding species to the Red list –
Dotterel, Eurasian Curlew Numenius arquata,
Merlin, Whinchat S a x icola
rub e t r a and Grey Wagtail
Motac illa cine rea – means that
there are as many species of
upland birds Red-listed as there
are farmland birds. In total, there
are now nine species of wader on
the Red list, and while the drivers
of the declines are likely to be
varied, it is clear that this group is
un d e r pressure (of 22 wa d er
species breeding in the UK, only
two remain on the Green list).
Brown et al. (2015) argued that
Eurasian Curlew should currently
be considered the UK’s most
pressing bird conservation pri-
ority, given the global concern
(Near Threatened) for the
species, the significance of the
UK’s breeding population and the
rapid decline in that population.
Another concern raised by the
BoCC3 assessment was population
decline in a growing number of
long-distance migrants, particu-
larly those that winter in sub-
Saharan Africa, and more
specifically in the humid tropics
(which have shown greater recent
declines than species wintering in
ot her r egion s; Hay how et al.
2014). A further three Afro-
Palearctic migrants, Common
Nightingale, Pied Flycatcher and
Whinchat, moved to the Red list in
this review, and declines have con-
tinued in the majority of those
listed already.
742
Eaton et al.
British Birds 108 • December 2015 • 708–746
429. The UK holds about half the world’s population of
Greenland White-fronted Geese Anser albifrons flavirostris in
winter. The most recent census results (2014/15) indicate the
lowest numbers in Britain for 30 years. The ultimate causes
of a collapse in productivity remains poorly understood, but
probably relates to changing spring weather conditions and
competition with Canada Geese Branta canadensis on the
breeding areas – probably acting in combination.
Andy Hay/RSPB-images

Climate change may be behind
some of the changes in listings
re p or ted her e. Ma ny sp eci e s are
thought to benefit from climate
change (e.g. Pearce-Higgins e t a l.
2013), and the population increases in
Little Egret Eg r e tta ga r zetta and
Firecrest Regulus ignicapilla, which
have re sulted in their move to the
Green list, are like ly to be at l eas t
partly in response to the UK’s
warming climate. Other species may
be adverse ly a ffec t ed by the UK’s
changing climate, including those at
the southern edge of their range for
which the ‘climatic envelope’ (the area
within which climatic conditions are
suitable for a species) is moving away
from the UK (Huntley et al. 2007).
This could be the case, for example,
for Dotterel, although other pressures,
such as increased nitrogen deposition
and grazing, may have caused its
decline (Hayhow et al. 2015). Other
climate change impacts include the
shifting of wintering ranges, which
has led to UK population declines in
White-fronted Goose and Ringed
Plover Charadrius hiaticula, and the
influence of climate upon marine
food chains, which is affecting the food sup-
plies of the Kittiwake (Freder iksen et al.
2007) and other seabirds.
BoCC at the race level
This was the second BoCC assessment to look
at the status of regularly occurring races of
birds in the UK, and we believe that they
serve as a useful complement to the species-
level assessments. We recommend that they
are used to draw distinctions between the dif-
fering status of races of the same species,
enabling better targeted conservation action
– for example towards the nominate race of
Black-tailed Godwit rather than the pros-
pering Icelandic race L. l. islandica. In addi-
tion, we should highlight the precarious
status of some races that are endemic, or
nearly so, to the UK. While the loss of
Wryneck as a UK breeding species is to be
lamented, our birds were of the nominate
ra c e , which is still found widely acro s s
Europe; the rapidly declining British popula-
tions of Lesser Spotted Woodpecker Dendro-
copos minor comminutus and Willow Tit
Poecile montana kleinschmidti are of endemic
races, so if lost would be gone forever.
The future of BoCC
Whi le BoCC assessments provide a clear
found ation for identi fyin g prio rity bird
species, this is not the only way of doing so,
and indeed a different approach has been
used to identify priority species for the UK’s
devolved administrations. Assessment against
the BoCC criteria is rather a ‘data-hungry’
process, designed around the evidence avail-
able for birds, but it is simply not possible to
replicate this approach for most other taxa,
for which our knowledge is much poorer.
Th is leaves birds as an except ion to the
growing practice of conducting nati onal
(usually for Great Britain, although some-
times for Britain and Ireland and occasion-
ally for individual nations) Red List
assessments using IUCN criteria (IUCN
743British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4
430. The Greenfinch Chloris chloris is Green-listed as a
species in this review, yet the British race C. c. harrisoni
is Red-listed as a result of recent decline, driven by
outbreaks of the parasitic disease trichomonosis.
Ben Hall/RSPB-images

2012). Burns et al. (2013) found British Red
List assessments for 6,225 species of wildlife,
but in the two years since then new assess-
ments have been published, or are near pub-
lication, for many groups. It may be that
while maintaining the series of BoCC assess-
ments we also need to consider a national
IUCN Red List assessment for birds, to
enable a level playing field when assessing
conservation priorities across all of the UK’s
biodiversity. We do, however, retain reserva-
tions about the regional IUCN Red Listing
process, and the suitability of assessments
focused on extinction risk alone for conser-
vation prioritisation and action in the UK
(see Eaton et al. 2005).
At pre sent , BoCC and other priority-
listing approaches are based solely on the
current status of species, and give no consid-
eration of likely future changes. We know
that our environment is undergoing rapid
changes, which will affect our bird popula-
ti o n s f o r b e t ter or worse . For exampl e ,
Huntley et al. (2007) used climate envelope
modelling to show how the ranges of Euro-
pean breeding species were likely to move
north and east in response to climate change
by the late twenty-first century. As a conse-
quence, we suspect that conditions in the UK
might become more favour able for some
species, but less favourable for others. Ausden
et al. (2015) predicted which species are likely
to be gained and lost as breeding species in
the UK, forecasting the arrival of Short-toed
Eagle Circaetus gallicus and Melodious
Warbler Hippolais polyglotta among others,
but also the climate-driven loss of breeding
species such as Common Scoter Melanitta
nigra and Pintail. This prompts the question
of whether our priority setting should con-
sider predicted future change, although it is
not immediately clear how those predicted
changes should be treated. Should we list
species that have yet to begin breeding in the
UK, to help ensure that we are ready for them
when they do? After all, conserving those
sp e c i es fo r which lowe r latit u d es ar e
becoming less suitable is likely to become
increasingly important.
The BoCC Red list is now lengthy, and
contains a spread of species for which we
have varying conservation concern. Some are
considered to be under the threat of extinc-
tion globally, or are undergoing dramatic
declines here that may lead to extinction in
the UK – Willow Tit, Turtle Dove and Caper-
caillie, to name just three of the 19 species
suggested as being at high risk of UK extinc-
tion by Ausden et al. (2015). Other Red-listed
sp e cies , while sti l l much- depl e ted fro m
744
Eaton et al.
British Birds 108 • December 2015 • 708–746
431. The Green Woodpecker Picus viridis is one of 22 species moving from Amber to Green,
reflecting its improved status in Europe.
Edmund Fellowes/BTO

previous levels, have shown stable or even
increasing trends in recent years, for example
Song Thrush Turdus philomelos.
This fourth BoCC assessment now sits
within the six-year cycle of reporting to the
European Commission, and we anticipate
fu t u re B o C C reviews re m aining so. A
timetable for EU reporting requirements, the
production of new UK population estimates
by APEP, and new European Red List assess-
ments should enable us to produce the fifth
BoCC in 2021. In the intervening period, it is
vital that we maintain the monitoring pro-
grammes that BoCC relies upon, and con-
tinue to work with and support the UK’s
many thousands of dedicated birdwatchers to
improve our evidence base. As mentioned
previously, gaps in data remain, and while we
are enduring lean times for the funding of
conservation activities, we should strive to
find efficient and imaginative ways of
improving our monitoring to ensure that
species do not slip through the net. Most
importantly, we argue that there should be
no let-up in our conservation action for the
species most in need of it.
Acknowledgments
We would like to thank the many colleagues who have
helped with access to data and provided advice during
the assessment process, including Ian Burfield, Christina
Ieronymidou and Rob Pople at BirdLife International,
Dawn Balmer, Simon Gillings, Chas Holt and Dario
Massimino at the BTO, Daniel Hayhow and Simon
Wotton at the RSPB, Dave Baines (GWCT), Roddy
Mavor and Matt Parsons (JNCC), Mark Holling (RBBP)
and Digger Jackson. Moreover, we wish to acknowledge
and thank the thousands of volunteers partaking in
study groups, conducting surveys as part of formal
monitoring schemes and submitting records through
other channels; without their efforts this assessment,
and the value it provides for conser vation in the UK,
would not be possible.
References
Aebischer, N. J., Evans, A. D., Grice, P. V., & Vickery, J. A.
2000. Ecology and Conservation of Lowland Farmland
Birds. BOU, Tring.
Ausden, M., Bradbur y, R., Brown, A., Eaton, M., Lock, L.,
& Pearce-Higgins, J. 2015. Climate change and
Britain’s birdlife: what might we expect?
Brit. Wildlife 26: 161–174.
Balmer, D. E., Gillings, S., Caffrey, B. J., Swann, R. L.,
Downie, I. S., & Fuller, R. J. 2013. Bird Atlas 2007–11:
the breeding and wintering birds of Britain and Ireland.
BTO Books, Thetford.
Batten, L. A., Bibby, C. J., Clement, P., Elliott, G. D., &
Porter, R. F. 1990. Red Data Birds in Britain.
Poyser, London.
BirdLife International. 2004. Birds in Europe: population
estimates, trends and conservation status.
BirdLife International, Cambridge.
— 2015. European Red List of Birds. Office for Official
Publications of the European Communities,
Luxembourg.
British Ornithologists’ Union (BOU). 2008. Records
Committee: 36th Report. Ibis 150: 218–220.
— 2013. The British List: A Checklist of Birds of
Britain. (8th edition). Ibis 155: 635–676.
Broughton, R. K. 2009. Separation of Willow Tit and
Marsh Tit in Britain: a review. Brit. Birds 102: 604–
616.
Brown, D., Wilson, J., Douglas, D., Thompson, P., Foster,
S., McCulloch, N., Phillips, J., Stroud, D., Whitehead,
S., Crockford, N., & Sheldon, R. 2015. The Eurasian
Curlew – the most pressing bird conservation
priority in the UK? Brit. Birds 108: 660–668.
Burns, F., Eaton, M. A., Gregory, R. D., Al Fulaij, N.,
August, T. A., Biggs, J., Bladwell, S., Brereton, T., Brooks,
D. R., Clubbe, C., Dawson, J., Dunn, E., Edwards, B.,
Falk, S. J., Gent, T., Gibbons, D. W., Gurney, M.,
Haysom, K. A., Henshaw, S., Hodgetts, N. G., Isaac,
N. J. B., McLaughlin, M., Musgrove, A. J., Noble, D. G.,
O’Mahony, E., Pacheco, M., Roy, D. B., Sears, J.,
Shardlow, M., Stringer, C., Taylor, A., Thompson, P.,
Walker, K. J., Walton, P., Willing, M. J., Wilson, J., &
Wynde, R. 2013. State of Nature Report. The State
of Nature par tnership.
Butchart, S. H. M., Stattersfield, A. J., Baillie, J., Bennun,
L. A., Stuart, S. N., Akçakaya, H. R., Hilton-Taylor, C.,
& Mace, G. M. 2005. Using Red List indices to
measure progress towards the 2010 target and
beyond. Phil. Trans. Royal Soc. B. 360: 255–268.
Cramp, S., Bourne, W. R. P., & Saunders, D. 1974.
The Seabirds of Britain and Ireland. Collins, London.
Defra. 2014. UK Biodiversity Indicators 2014.
http://jncc.defra.gov.uk/pdf/UKBI2014.pdf
Eaton, M. A., Gregory, R. D., Noble, D. G., Robinson,
J. A., Hughes, J., Procter, D., Brown, A. F., & Gibbons,
D. W. 2005. Regional IUCN Red Listing: the process
as applied to birds in the United Kingdom. Cons.
Biol. 19: 1557–1570.
—, Brown, A. F., Noble, D. G., Musgrove, A. J., Hearn,
R. D., Aebischer, N. J., Gibbons, D. W., Evans, A., &
Gregory, R. D. 2009. Birds of Conser vation Concern
3: the population status of birds in the United
Kingdom, Channel Islands and Isle of Man. Brit. Birds
102: 296–341.
European Commission. 2015. The State of Nature in
the European Union. Report on the status of and
trends for habitat types and species covered by the
Birds and Habitats Directives for the 2007–2012
period as required under Article 17 of the Habitats
Directive and Article 12 of the Birds Directive.
European Commission, Brussels.
Frederiksen, M., Edwards, M., Mavor, R. A., & Wanless, S.
2007. Regional and annual variation in Black-legged
Kittiwake breeding productivity is related to sea
surface temperature. Marine Ecology Progress Series
350: 137–143.
Fuller, R. J., Noble, D. G., Smith, K. W., & Vanhinsbergh,
D. 2005. Recent declines in populations of
woodland birds in Britain: a review of possible
causes. Brit. Birds 98: 116–143.
Gibbons, D. W., Reid, J. B., & Chapman, R. A. 1993.
The New Atlas of Breeding Birds in Britain and Ireland:
745British Birds 108 • December 2015 • 708–746
Birds of Conservation Concern 4

746
Eaton et al.
British Birds 108 • December 2015 • 708–746
1988–1991. Poyser, London.
—, Avery, M. I., & Brown, A. F. 1996a. Population trends
of breeding birds in the United Kingdom since
1800. Brit. Birds 89: 291–305.
—, —, Baillie, S. R., Gregory, R. D., Kirby, J., Porter, R. F.,
Tucker, G. M., & Williams, G. 1996b. Bird species of
conservation concern in the United Kingdom,
Channel Islands and Isle of Man: revising the Red
Data List. RSPB Conservation Review 10: 7–18.
Gregory, R. D., Wilkinson, N. I., Noble, D. G., Robinson,
J. A., Brown, A. F., Hughes, J., Procter, D., Gibbons,
D. W., & Galbraith, C. A. 2002. The population status
of birds in the United Kingdom, Channel Islands and
Isle of Man: an analysis of conser vation concern
2002–2007. Brit. Birds 95: 410–448.
Harris, S. J., Massimino, D., Newson, S. E., Eaton, M. A.,
Balmer, D. E., Noble, D. G., Musgrove, A. J., Gillings, S.,
Procter, D., & Pearce-Higgins, J. W. 2015. The
Breeding Bird Sur vey 2014. BTO Research Report
673. BTO, Thetford.
Hayhow, D. B., Ewing, S., Baxter, A., Douse, A., Stanbury,
A., Whitfield, D. P., & Eaton, M. A. 2015. Changes in
the abundance and distribution of a montane
specialist bird, the Dotterel Charadrius morinellus,
in the UK over 25 years. Bird Study 62: doi:
10.1080/00063657.2015.1054145
—, Conway, G., Eaton, M. A., Grice, P. V., Hall, C., Holt,
C. A., Kuepfer, A., Noble, D. G., Oppel, S., Risely, K.,
Stringer, C., Stroud, D. A., Wilkinson, N., & Wotton,
S. 2014. The State of the UK’s Birds. RSPB, BTO,
WWT, JNCC, NE, NIEA, NRW & SNH. Sandy,
Bedfordshire.
Heath, M. F., & Evans, M. I. (eds.). 2000. Important Bird
Areas in Europe: priority sites for conservation. 1:
Northern Europe. BirdLife International, Cambridge.
Hoekstra, A. Y., & Wiedmann, T. O. 2014. Humanity’s
unsustainable environmental footprint. Science 344:
1114–1117.
Holling, M., & the Rare Breeding Birds Panel. 2014.
Rare Breeding Birds in the United Kingdom in 2012.
Brit. Birds 107: 504–560.
Holloway, S. 1996. The Historical Atlas of Breeding Birds
of Britain and Ireland: 1875–1900. Poyser, London.
Holt, C. A., Austin, G. E., Calbrade, N. A., Mellan, H. J.,
Hearn, R. D., Stroud, D. A., Wotton, S. R., &
Musgrove, A. J. 2015. Waterbirds in the UK in
2013/14: The Wetland Bird Sur vey. BTO, RSPB &
JNCC, in association with the WWT. BTO, Thetford.
del Hoyo, J., & Collar, N. J. 2014. Illustrated Checklist of
the Birds of the World. Volume 1: Non-passerines. Lynx
Edicions, Barcelona.
Huntley, B., Green, R. E., Collingham,Y. C., & Willis, S. G.
2007. A Climatic Atlas of European Breeding Birds.
Durham University, RSPB and Lynx Edicions,
Barcelona.
IUCN. 2012. Guidelines for Application of IUCN Red List
Criteria at Regional and National Levels: Version 4.0.
IUCN, Gland, Switzerland & Cambridge, UK.
Johnson, J. A., Watson, R. T., & Mindell, D. P. 2005.
Prioritizing species conservation: does the Cape
Verde Kite exist? Proc. Royal Soc. B: 272: 1365–1371;
doi: 10.1098/rspb.2005.3098
Lack, P. C. 1986. The Atlas of Wintering Birds in Britain
and Ireland. Poyser, London.
Lawson, B., Robinson, R. A., Colvile, K. M., Peck, K. M.,
Chantrey, J., Pennycott, T. W., Simpson, V. R., Toms,
M. P., & Cunningham, A. A. 2012. The emergence
and spread of finch trichomonosis in the British
Isles. Phil. Trans. Royal Soc. B. 367: 2852–2863.
Lloyd, C ., Tasker, M. L., & Partridge, K. 1991. The Status
of Seabirds in Britain and Ireland. Poyser, London.
Mitchell, P. I., Newton, S., Ratcliffe, N., & Dunn, T. E.
2004. Seabird Populations of Britain and Ireland.
Poyser, London.
Musgrove, A. J., Aebischer, N. J., Eaton, M. A., Hearn,
R. D., Newson, S. E., Noble, D. G., Parson, M., Risely,
K., & Stroud, D. A. 2013. Population estimates of
birds in Great Britain and the United Kingdom.
Brit. Birds 106: 64–100.
Pearce-Higgins, J. W. 2013. Evidence of climate change
impacts on populations using long-term datasets:
Technical Paper 7. Terrestrial Biodiversity Climate
Change Report Card. LWEC, Norwich.
Sharrock, J. T. R. 1976. The Atlas of Breeding Birds in
Britain and Ireland. Poyser, Berkhamsted.
Stroud, D. A., Chambers, D., Cook, S., Buxton, N.,
Fraser, B., Clement, P., Lewis, P., McLean, I., Baker, H.,
& Whitehead, S. 2001. The UK SPA Network: its
scope and content. Vol. 2: Species accounts. JNCC,
Peterborough.
—, Bainbridge, I., Maddock, A., Anthony, S., Buxton, N.,
Chambers, D., Enlander, I., Hearn, R., Jennings, K.,
Wilson, J., & Whitehead, S. (eds.). In prep. The Status
of UK SPAs in the 2000s: the third network review.
JNCC, Peterborough.
Tucker, G. M., & Heath, M. F. 1994. Birds in Europe: their
conservation status. BirdLife International,
Cambridge.
Vickery, J. A., Ewing, S. R., Smith, K. W., Pain, D. J., Barlein,
F., Skorpilova, J., & Gregory, R. D. 2014. The decline
of Afro-Palearctic migrants and an assessment of
potential causes. Ibis 156: 1–22.
Wetlands International. 2015. Waterbird Population
Estimates. Retrieved from http://wpe.wetlands.org
White, S., & Kehoe, C. 2015a. Report on scarce
migrant birds in Britain in 2011–12: part 1, non-
passerines. Brit. Birds 108: 126–157.
— & — 2015b. Report on scarce migrant birds in
Britain in 2011–12: part 2, passerines. Brit. Birds 108:
192–219.
Whitfield, D. P., Fielding, A. H., Mcleod, D. R., Mor ton, K.,
Stirling-Aird, P., & Eaton, M. A. 2007. Factors
constraining the distribution of Golden Eagles
Aquila chrysaetos in Scotland. Bird Study 54: 199–
211.
Mark A. Eaton, Leigh Lock and Richard D. Gregory, The RSPB Centre for Conservation Science,
The Lodge, Sandy, Bedfordshire SG19 2DL; e-mail Mark.Eaton@rspb.org.uk
Nicholas J. Aebischer, Game & Wildlife Conservation Trust, Fordingbridge, Hampshire SP6 1EF
Andy F. Brown, Natural England, Northminster House, Peterborough PE1 1UA
Richard D. Hearn, WWT, Slimbridge, Gloucestershire GL2 7BT
Andy J. Musgrove and David G. Noble, BTO, The Nunnery, Thetford, Norfolk IP24 2PU
David A. Stroud, JNCC, Monkstone House, City Road, Peterborough PE1 1JY