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Acta Herpetologica 9(2): 253-258, 2014
ISSN 1827-9635 (print) © Firenze University Press
ISSN 1827-9643 (online) www.fupress.com/ah
DOI: 10.13128/Acta_Herpetol-14968
Molecular assessment of Podarcis sicula populations in Britain, Greece
and Turkey reinforces a multiple-origin invasion pattern in this species
I S-R,*, D S, D. J H, S F, C D, J F,
G D, C A, M A. C
1 CIBIO-InBIO-UP, Research Centre in Biodiversity and Genetic Resources, Universidade do Porto, Campus Agrário de Vairão, Rua
Padre Armando Quintas 7, 4485-661 Vairão, Vila do Conde, Portugal. *Corresponding author. E-mail: irocha@cibio.up.pt
2 Amphibian & Reptile Conservation, e Witley Centre, Witley, Godalming, Surrey GU8 5QA, United Kingdom
3 Friedrich-Ebert-Str. 62, Biberach an der Riss, Germany DE-88400
4 Zoological Museum, Department of Biology, University of Athens, Panepistimioupolis, GR-15784, Greece
Submitted on 2014, 2nd September, revised on 2014, 17th October, accepted on 2014, 21st October
Editor: Gentile Francesco Ficetola
Abstract. Biological invasions are a challenge to conservation and constitute a threat to biodiversity worldwide. e
Italian wall lizard Podarcis sicula has been widely introduced, and seems capable of adapting to most of the regions
where it is established and to impact on native biota. Here we construct a phylogenetic framework to assess the origin
of the introduced populations in the United Kingdom, Greece and Turkey comparing cytochrome-b gene sequences
of lizards from ve locations to published sequences from the native range and other non-native locations. e results
support an origin from central Italy for the United Kingdom population, from the Adriatic region for the Greek pop-
ulation and from Calabria for the population from Turkey. ese results emphasise the multiple-source pattern of
introduction of this species identied in previous studies. e improvement in the knowledge of the origin and path-
ways by which invaders arrive in new areas, as well as the monitoring of their populations, are crucial for successful
strategies to deal with exotic species.
Keywords. Biological Invasions, Italian wall lizard, cytochrome b, human-mediated introductions.
Biological invasions are a major concern to biodi-
versity conservation due to the threat to native biota
(Simberlo et al., 2013). e Italian wall lizard, Podarcis
sicula, is one such reptile species that has been widely
introduced (Kraus, 2009). From its native distribution in
the Italian Peninsula, Sicily and the north Adriatic coast,
this species is considered to have been introduced in sev-
eral other places, such as the Tyrrhenian Islands, Corsica
and Sardinia, Menorca in the Balearics and in islands and
coastal areas of the eastern Adriatic Sea (Corti, 2006).
Besides these regions, scattered introduced populations
are also known from the Iberian Peninsula, in Canta-
bria (Meijide, 1981), Almería (Mertens and Wermuth,
1960), Lisbon (González de la Vega et al., 2001), La Rio-
ja (Valdeón et al., 2010) and near Barcelona (Rivera et
al., 2011); in Southern France, in Toulon and Château
d’If Island (Morgue, 1924; Orsini, 1984); in Switzerland
(Schulte and Gebhart, 2011); in Turkey, in Istanbul sur-
roundings and the Marmara Islands (Mollov, 2012; Ilgaz
et al., 2013); in North Africa, in Tunisia and Tripoli
(Arnold and Ovenden, 2002); and in the United States, in
Philadelphia, Kansas, New York and California (Deichsel
et al., 2010; Kolbe et al., 2013). Very recently, two addi-
tional introductions have been reported in the United
Kingdom (Hodgkins et al., 2012) and in Greece (Adamo-
poulou, 2014).
is Mediterranean lizard is very eclectic regarding
habitat choice, being found both in natural areas, agri-
cultural environments and in urban areas (Capula, 1994;
Corti 2006). Exotic populations of P. sicula have become
254 I. Silva-Rocha et alii
established and undergone expansion in dierent regions
encompassing a wide spectrum of environmental con-
ditions, namely in North America (Burke et al., 2002;
Burke and Ner, 2005). erefore, this lizard appears to be
an eective and successful coloniser. e ecological and
behavioural traits of this species also contribute to the
success in the new area, causing a great impact on native
lizards with which P. sicula is able to compete. Behav-
ioural interference with native Podarcis species have
been reported, namely with P. melisellensis in the Adri-
atic coast (Downes and Bauwens, 2002) which can result
in the extinction of the latter when the introduction of
P. sicula takes place in small islets (Nevo et al., 1972).
Moreover, hybridisation with other Podarcis species is
also documented, namely with the endemic P. tiliguerta
in Sardinia (Capula, 2002), with P. raonei in the Aeo-
lian islands (Capula et al., 2002) and with P. wagleriana
in Sicily (Capula, 1994). ese negative eects on native
biota, hence, qualify this species as a problematic invader
(Kraus, 2009).
Given the potential adverse eects of P. sicula out of
its native range, it becomes crucial to develop eective
management strategies. Understanding the colonisation
patterns of this successful invader provides the basis for
delineating more eective preventive measures (Dorcas
et al., 2010). A single source of introduction might facili-
tate the introduction of control measures on target popu-
lations, regions and invasion pathways, while multiple
sources would indicate a general invasive character of the
species requiring more global measures at a species level.
Molecular evidence supporting the origin of P. sicula is
still lacking for many introduced populations. Recently,
taking advantage of the available phylogeographic infor-
mation for the native range of the species Podnar et al.
(2005), Silva-Rocha et al. (2012) and Kolbe et al. (2013)
revealed multiple sources for the populations of the Ibe-
rian Peninsula and Menorca, and of the United States.
Both studies concluded that the pathways by which the
species is being introduced are well distinct between
cases, ranging from the pet trade, to cargo and the nurs-
ery trade of olive trees (Valdeón et al., 2010; Rivera et al.
2011) as well as escaping from captivity and deliberate
release (Deichsel et al., 2010).
In this study, we use phylogenetic analyses to assess
the putative origin of three other recently introduced
populations, occurring in the United Kingdom, Greece
and Turkey. e UK population was introduced in 2010
and has already been eradicated (Hodgkins et al., 2012).
In Greece, the population was described as a very recent
introduction and was detected in 2014 (Adamopoulou,
2014). On the other hand, the population from Turkey
was introduced historically and is in apparent expansion
(Mollov, 2012; Ilgaz et al., 2013). e identication of the
origin of these three additional introduced populations is
expected to improve the picture of the colonization pat-
tern revealed by the previous studies.
One sample of P. sicula was collected from Mudan-
ya (locality reported by Mollov 2009; 40º22’5.844”N,
28º54’7.56”E), one sample from Güzelyah (40º21’
52.416”N, 28º54’7.56”E) and one sample from Iznik
(40º25’43.6434”N, 29º 43’ 45.7674”E) in Turkey, three
samples from Palaio Faliro (Athens; 37º55’9.38”N, 23º42’
0.50”E) in Greece and one sample from Buckinghamshire
(52º1’47.604”N, 1º1’10.308” W) in the United Kingdom.
Total genomic DNA was extracted from tail tissue and
a fragment of 687 base pairs of the mitochondrial gene
cytochrome b (cyt-b) was amplied by PCR using the
same primers and procedures described in Silva-Rocha et
al. (2012). e sequences generated in the present study
(GenBank accession numbers: KP036396-KP036402)
were aligned with 116 sequences downloaded from Gen-
Bank: 39 sequences from individuals of P. sicula from the
native range (Podnar et al., 2005), accession numbers:
AY185095, AY185094, AY770869–AY77090; 16 sequences
from the Iberia Peninsula and 7 from Menorca introduced
populations (Silva-Rocha et al., 2012), accession num-
bers: JX072938-JX072960; one sequence from Switzerland
(Schulte and Gebhart, 2011); 1 sequence from Califor-
nia (Deichsel et al., 2010), accession number: HQ154646;
and 52 sequences from Kolbe et al. (2013), from both
the introduced populations of the United States (nine
sequences) and from the native populations (43 sequenc-
es), accession numbers: JX186516-JX186568. Three
sequences from Podarcis muralis and P. melisellensis were
also downloaded from GenBank and used as outgroup
(accession numbers AY185096, AY185029 and AY185057),
following Podnar et al. (2005). We performed a Maximum
Likelihood (ML) phylogenetic analysis to infer the rela-
tionships between the cyt-b haplotypes using the soware
Mega 6 (Tamura et al., 2013). e model HKY + Gam-
ma was selected as the best model of sequence evolution
under the Bayesian Information Criterion (BIC), chosen
using Mega 6. Tree searches were performed using the
heuristic search mode. Node support was calculated over
1000 bootstrap replicates. In addition to the tree-build-
ing approach, we analysed the genealogical relationships
among the native and non-native haplotypes clustered in
the ‘Sicula’ clade (Podnar et al., 2005) by means of a sta-
tistical parsimony network using the soware TCS 1.21
(Clement et al., 2000), in order to get a better resolution
on relationships between closely related haplotypes.
e nal alignment includes 127 sequences of 687
base pairs. Four new haplotypes were identied from the
ve introduced locations here studied, and 78 haplotypes
255
Origin of introduced P. sicula
Fig. 1. ML Phylogenetic estimate of relationships between cytochrome b (cyt-b) haplotypes from native Podarcis sicula populations (Podnar
et al. 2005, Kolbe et al. 2013) and those from introduced populations generated in this study (Turkey and United Kingdom) and by Silva-
Rocha et al. 2012 and Kolbe et al. 2013 (Almeria, Cantabria, La Rioja, Lisbon, Menorca, New Jersey, California, New York and Kansas).
P. muralis and P. meliselensis were used as outgroups (not shown). Sequences downloaded from Genbank are named according to their
accession number. Main P. sicula haploclades are indicated by grey boxes and subclades are named according to the geographic origin of
haplotypes (native samples in italic). Samples from United Kingdom, Greece and Turkey are highlighted in grey and underlined. Bootstrap
support values are indicated above the nodes of interest.
256 I. Silva-Rocha et alii
were identied from the sequences generated by the pre-
vious studies (Podnar et al., 2005; Deischsel et al., 2010;
Schulte and Gebhart, 2011; Silva-Rocha et al., 2012; Kol-
be et al. 2013). In particular, one dierent haplotype was
found in the British and Greek locations each, while two
dierent haplotypes occurred in the Turkish populations.
e estimate of relationships based on ML indicates
that lizards from the United Kingdom belong to the
“Rome” clade found by Kolbe et al. (2013) (Fig. 1). is
result supports the hypothesis of Hodgkins et al. (2012)
that the origin of the lizards introduced in the Unit-
ed Kingdom was from a locality close to Rome. ese
authors stated that the lizards were found in June 2010
on a consignment of tufa (a type of so, porous lime-
stone) imported from Italy in March 2010 for a restora-
tion project of an 18th century landscape garden in Stowe,
Buckinghamshire. is hypothesis was also supported by
J. Foster (pers. comm.) who indicated Tivoli (ca. 30 km
east of Rome) as the origin of the building materials.
Lizards from Greece are included in the “Campestris-
sicula” clade, sharing the haplotype with lizards sampled in
the Adriatic region by Podnar et al. (2005) and with lizards
sampled in New Jersey by Kolbe et al. (2013). erefore,
the most probable origin for the Greek population is the
Adriatic region, which is geographically close to Greece.
The population was found in a narrow zone of sand
(dimensions approx. 90 × 15 m) between an overcrowded
beach and the tram station on the main avenue. e occu-
pied area is a small articial “park” of various trees planted
on bare sand. e park ocer noticed the presence of the
lizards since he started to plant the trees, so this could be
a probable vector by which the animals arrived. Unfor-
tunately, it is not possible to know the origin of the trees
since they were collected from the garbage. Furthermore,
we cannot exclude other potential introduction pathways,
since there is a big yacht marina less than 500 meters away
from the colony and a large port, Port of Piraeus, approxi-
mately 8km away (Adamopoulou, pers. comm.).
Fig. 2. Map of the introduced populations of Podarcis sicula analysed. (A) populations in Iberian Peninsula, United Kingdom and Switzer-
land, (B) populations in United States, (C) populations in Greece and Turkey.
257
Origin of introduced P. sicula
Regarding the Turkish population, their cyt-b haplo-
type clusters in the “Sicula” clade of Podnar et al. (2005)
(Fig. 1). e haplotype from Turkey seems to correspond
to the Calabrian stock, since is closely related to the
ones found in the Calabrian region. Accidental historical
introductions by people or merchant vessels are possible
pathways through which this population arrived in Tur-
key from southern Italy (Mollov, 2009).
Our ML results are in accordance with previous stud-
ies (Silva-Rocha et al., 2012; Kolbe et al., 2013), as can
be seen both in the ML tree (Fig. 1) and in the summary
map of Fig. 2.
Based on the additional sequences generated by Kol-
be et al. (2013) from lizards sampled in the native range,
it is possible to rene the inferred origin for the popula-
tions of Lisbon and Cantabria (northern Spain). Indeed,
our ML tree supports an origin from northwestern Tus-
cany for the Cantabria population in and from central
Italy around Rome for the Lisbon population which clus-
tered within the “Rome” clade.
e results of this study reinforce the multiple source
and pathways pattern suggested by Silva-Rocha et al.
(2012) and Kolbe et al. (2013) and conrm the invasive
potential of this species as a whole (Fig. 2). is reveals
once more the tendency of P. sicula to use man-made
objects as refuges and the role of these as an eective
vector for the introductions of this lizard. Regarding the
British population, the early detection and fast collection
of the individuals was the key to preventing the expan-
sion of this species from the formal garden where it was
rst observed (see details of the eradication in Hodg-
kins et al. 2012). e Greek population is established
and already has at least 50-60 individuals (Adamopou-
lou, 2014). Early eradication of this population is rec-
ommended. On the other hand, the Turkish populations
seem to be of more longstanding origin and are current-
ly in expansion towards the south of the Marmara Sea
(Mollov, 2009; Tok et al., 2014). A specic monitoring
program would be needed to assess in detail the extent
and progress of this expansion.
Overall, results obtained here accumulated to the
previous evidence demonstrating that the Italian wall
lizard P. sicula can be an eective invader. Its successful
acclimatization to environmental conditions dierent for
those prevailing in its original Mediterranean range such
as those in Switzerland or Central USA increases conser-
vation concern, since the probability to become invasive
is boosted by the adaptability of the species. Certainly,
documenting the origin and pathways of introduced pop-
ulations and monitoring the expansion of the populations
are needed to define effective management strategies
(Kraus, 2009; Simberlo et al., 2013).
ACKNOWLEDGMENTS
DS is supported by the FCT post-doctoral grant
SFRH/BPD/66592/2009 and IS-R by the FCT PhD grant
SFRH/BD/95745/2013 under the Programa Operacional
Potencial Humano – Quadro de Referência Estratégico
Nacional funds from the European Social Fund and Por-
tuguese Ministério da Educação e Ciência. e molecular
work of this study was funded by FCOMP-01-0124-FED-
ER-007062 FCT project PTDC/BIA-BEC/102179/2008,
PTDC/BIA-BEC/101256/2008, and partially nanced by
the project “Biodiversity, Ecology and Global Change”
co-nanced by North Portugal Regional Operational Pro-
gramme 2007/2013 (ON.2 – O Novo Norte), under the
National Strategic Reference Framework (NSRF), through
the European Regional Development Fund (ERDF) and
by the project “Biodiversity Conservation in a Changing
World” nanced by the Portuguese Integrated Program
of IC&DT Call Nº 1/SAESCTN/ALENT-07-0224-FED-
ER-001755.
REFERENCES
Adamopoulou, C. (2014): First record for Podarcis siculus
(Ranesque-Schmaltz, 1810) from Greece. Herpeto-
zoa 27 (in press).
Arnold, E.N., Ovenden, D.W. (2002): A eld guide to the
reptiles and amphibians of Britain and Europe. Harp-
er Collin.
Burke, R.L., Hussain, A.A., Storey, J.M., Storey, K.B.
(2002): Freeze tolerance and supercooling ability in
the Italian wall lizard, Podarcis sicula, introduced to
Long Island, New York. Copeia 2002: 836-842.
Burke, R.L., Ner, S.E. (2005): Seasonal and diel activity
patterns of Italian Wall Lizards, Podarcis sicula camp-
estris, in New York. Northeast. Nat. 12: 349-360.
Capula, M. (1993): Natural hybridization in Podarcis sic-
ula and P. wagleriana (Reptilia: Lacertidae). Biochem.
Syst. Ecol. 21: 373-380.
Capula, M. (1994): Population genetics of a colonizing
lizard: Loss of variability in introduced populations of
Podarcis sicula. Experentia 50: 691-696.
Capula, M. (2002): Genetic evidence of natural hybridi-
zation between Podarcis sicula and Podarcis tiliguerta
(Reptilia). Amphibia-Reptilia 23: 313-321.
Capula, M., Luiselli L., Bologna M. A., Ceccarelli A.
(2002): e decline of the Aeolian wall lizard, Podar-
cis raonei: causes and conservation proposals. Oryx
36: 66-72.
Clement, M., Posada, D., Crandall, K.A. (2000): TCS: a
computer program to estimate gene genealogies. Mol.
Ecol. 9: 1657-1660.
258 I. Silva-Rocha et alii
Corti, C. (2006): Podarcis sicula. Lucertola campestre,
Italian wall lizard. In: Atlante degli Anbi e dei Reit-
tili d’Italia. Atlas of Italian Amphibians and Reptiles.
p. 486-489. Sindaco R., Doria G., Razzeti E., Bernini
F., Eds, Polistampa, Firenze, Italy.
Deichsel, G., Nas, G., Hakim, J. (2010): Podarcis siculus
(Italian Wall Lizard) USA: California. Herpetol. Rev.
41: 513-514.
Dorcas, M.E., Wilson, J.D., Gibbon, J.W. (2010): Can
invasive Burmese pythons inhabit temperate regions
of the southeastern United States? Biol. Invasions 13:
793-802.
Downes, S., Bauwens, D. (2002): An experimental dem-
onstration of direct behavioural interference in two
Mediterranean lacertid lizard species. Anim. Behav.
63: 1037-1046.
Gonzalez de la Vega, J.P., Gonzalez-Garcia, J.P., Garcia-
Pulido, T., Gonzalez-Garcia. G. (2001): Podarcis sicula
(Lagartija italiana), primera cita para Portugal. Bol.
Asoc. Herpetol. Esp. 12: 9.
Hodgkins, J., Davis, C., Foster, J. (2012): Successful rapid
response to an accidental introduction of non-native
lizards Podarcis siculus in Buckinghamshire, UK.
Conserv. Evid. 9: 63-66.
Ilgaz, C., Kumlutas, Y., Sozen, M. (2013): New locality
record for Podarcis siculus hieroglyphicus (Berthold,
1842) (Squamata: Lacertidae) in the western Black Sea
region of Anatolia. Turk. J. Zool. 37: 123-127.
Kolbe, J.J., Lavin, B.R., Burke, R.L., Rugiero, L., Capula,
M., Luiselli, L. (2013): e desire for variety: Italian
wall lizard (Podarcis siculus) populations introduced
to the United States via the pet trade are derived from
multiple native-range sources. Biol. Invasions. 15:
775-783.
Kraus, F (2009) Alien Reptiles and Amphibians: A
Scientific compendium and analysis. Springer, New
Yo r k .
Meijide, M. (1981): Una nueva población de Lacerta sic-
ula Ranesque para el norte de España. Acta Verte-
brata 8: 304-305.
Mertens, R. and Wermuth, H. (1960): Die Amphibien
und Reptilien Europas. Verlag Waldemar Kramer,
Frankfurt am Main.
Mollov, I. (2009): A new locality of the Italian wall lizard
Podarcis siculus (Rafinesque-Schmaltz, 1810) from
Turkey. ZooNotes 6: 1-3.
Morgue, M. (1924): Note succinte sur les espèces de Lac-
erta muralis des îles du Golfe de Marseille. Bull. Soc.
Linn. Lyon 3: 55.
Nevo, E., Gorman, G. C., Soulé, M., Yang, E. J., Clo-
ver, R., Jovanovic, V. (1972): Competitive exclusion
between insular Lacerta species (Sauria, Lacertidae).
Oecologia 10: 183-190.
Orsini, J.P. (1984): A propos du Lézar sicilien Podarcis
sicula en Provence. Bull. C.R.O.P 6: 8.
Podnar, M., Mayer, W., Tvrtković, N. (2005): Phyloge-
ography of the Italian wall lizard, Podarcis sicula, as
revealed by mitochondrial DNA sequences. Mol. Ecol.
14: 575-588.
Rivera, X., Arribas, O., Carranza, S., Maluquer-Margalef,
J. (2011): An introduction of Podarcis sícula in Cata-
lonia (NE Iberian Peninsula) on imported olive trees.
Bull. Soc. Catalana Herpetol. 19: 79-85.
Schulte, U. Gebhart, J. (2011): Geographic origin of a
population of the Italian Wall Lizard Podarcis siculus
(Ranesque-Schmaltz,1810), introduced north of the
Alps. Herpetozoa 24: 96-97.
Silva-Rocha, I., Salvi, D., Carretero, M.A. (2012): Genetic
data reveal a multiple origin for the populations of the
Italian Wall lizard Podarcis sicula (Squamata: Lacerti-
dae) introduced in the Iberian Peninsula and Balearic
Islands. Ital. J. Zool. 79: 502-510.
Simberlo, D., Martin, J.L., Genovesi, P., Maris, V., War-
dle, D., Aronson, J., Courchamp, F., Galil, B., Garcia-
Berthou, E., Pascal, M., Pysek, P., Sousa, R., Tabacchi,
E., Vila, M. (2013): Impacts of biological invasions:
what’s what and the way forward. Trends Ecol. Evol.
28: 58-66.
Tamura, K., Stecher, G., Peterson, D., Filipski, A., Kumar,
S. (2013). MEGA6: Molecular Evolutionary Genetics
Analysis version 6.0. Mol. Biol. Evol. 30: 2725-2729.
Tok, C.V., Çiçek, K., Hayretdag S., Tayhan, Y., Yakin, B.Y.
(2014). Range extension and morphology of the Ital-
ian wall lizard, Podarcis siculus (Ranesque-Schmaltz,
1810) (Squamata: Lacertidae), from Turkey. Turk. J.
Zool. 38: 1-7.
Valdeón, A., Perera, A., Costa, S., Sampaio, F., Carretero,
M.A. (2010): Evidencia de una introducción de Podar-
cis sicula desde Italia a España asociada a una import-
ación de olivos (Olea europaea). Bol. Asoc. Herpetol.
Esp. 21: 122-126.
