Pierre Defos Du Rau

Office Français de la Biodiversité · exploited species unit

Sea-level rise (SLR) is expected to cause major changes to coastal wetlands, which are among the world's most vulnerable ecosystems and are critical for nonbreeding waterbirds. Because strategies for adaptation to SLR, such as nature-based solutions and designation of protected areas, can locally reduce the negative effects of coastal flooding unde...

Connectivity shapes species distribution across fragmented landscapes. Assessing landscape resistance to dispersal is challenging because dispersal events are rare and difficult to detect especially for elusive species. To address these issues, spatial occupancy models have been developed to integrate the resistance surface concept of landscape eco...

Human pressure on ecosystems has strongly increased over the last decades and now impacts even the most remote regions. To help mitigate these impacts, it is crucial to designate protected areas in regions that retain a high level of ecological integrity. However, ecological data remain scarce for many such areas, making the systematic design of ne...

Wildlife count data are used to provide estimates of population abundance. To quantify changes in the size of populations, it is necessary to determine the precision of abundance estimates. Ground or aerial survey methods are often intended to be a census and thus do not provide estimates of precision. One solution is to switch approaches to a diff...

FAO/RESSOURCE Project poster published at the XVth Word Forestry Congress (Seoul, Korea, May 2022), FAO

Abundance of wild species is generally used to prioritize and evaluate networks of protected areas (PAs). Waterbird abundance information, collected through the International Waterbird Census (IWC), is widely used to identify key sites for migratory waterbirds, which are listed in the Critical Site Network (CSN) database. We reviewed IWC informatio...

The Mediterranean Basin is a biodiversity hotspot. Wetlands make a key contribution to this status, but many of them remain outside the Ramsar network fifty years after the establishment of the Ramsar Convention. Here we evaluate the extent to which the Mediterranean Ramsar network covers wetlands of international importance for wintering waterbird...

In biodiversity monitoring, large datasets are becoming more and more widely available and are increasingly used globally to estimate species trends and conservation status. These large‐scale datasets challenge existing statistical analysis methods, many of which are not adapted to their size, incompleteness and heterogeneity. The development of sc...

In several regions of the world, remoteness of potential bird hotspots and lack of trained observers have often prevented countries from effectively designing proper monitoring schemes at a national scale. For many countries, it is not known if certain bird strongholds have been missed that should be included for more complete censuses. Such gaps a...

Although biological conservation is based on international agreements, its effectiveness depends on how countries implement such recommendations as effective conservation tools. The Ramsar Convention is the oldest international treaty for wetland and waterbird conservation, establishing the world's largest network of protected areas. However, since...

En Camargue, plusieurs groupes de chasseurs ont expérimenté des changements dans leurs modalités de gestion des habitats et des prélèvements, dans l’objectif de pratiquer une activité cynégétique à la fois plus durable et plus favorable à la biodiversité. Nous présentons ici quelques exemples de ces différentes pratiques mises en œuvre sur cinq ter...

Since 2012, the Mediterranean waterbirds network, coordinated by Tour du Valat and ONCF, greatly improved IWC data quality in space and time in North African countries. However, among the overall waterbird monitoring dataset for North Africa, 67% are missing values: there was a specific issue to solve for analysing data to obtain a valuable result...

La combinaison d’interventions telles que le débroussaillage et le pâturage peut-elle efficacement limiter l’extension du séneçon en arbre dans les habitats naturels des zones humides côtières ? Une expérience menée pendant cinq années en Camargue démontre l’efficacité, mais aussi les limites, de ces modes de gestion.

The Mediterranean Waterbird Network works since 2012 on the improvement of the qulaity of data of waterbirds censuses in the North african region. The poster is about the success of the collaboration between the five north african countries and France but also on the potentiality of improvemnt of waterbird monitoring schemes and wetland conservatio...

Le plomb est un métal toxique dont l'utilisation dans les produits de consommation courante (peinture, essence, etc.) est progressivement éliminée par voie réglementaire dans la plupart des pays. Les projectiles de chasse ne font pas exception et bon nombre de pays ont désormais interdit l'utilisation du plomb pour la chasse dans les zones humides....

The International Waterbird Census (IWC) is one of the most widespread biodiversity monitoring programs, assessing waterbird populations in the framework of several international agreements including the African-Eurasian migratory Waterbirds Agreement and the Ramsar Convention. In 2013, the IWC was coordinated for the first time across the whole of...

Distribution and status of the Ocellated lizard Timon lepidus (Daudin, 1802) (Squamata, Sauria, Lacertidae) in western “Occitanie” (ancient “Midi-Pyrénées” region in the Southwest of France). The current knowledge of the Ocellated lizard Timon lepidus’s distribution and status in the former “Midi-Pyrénées” region is exposed. This lizard is at prese...

The Lesser Crested Tern Thalasseus bengalensis emigratus breeding population in the Mediterranean is found exclusively in Libya, on the two coastal islands of Gara and Elba and one wetland on the mainland coast at Benghazi. In order to improve knowledge of the species migration to wintering quarters in West Africa, a ringing programme was conducted...

The International Waterbird Census (IWC, coordinated internationally by Wetlands International), is one of the largest global biodiversity monitoring programmes. It contributes to the implementation of the African-Eurasian Waterbird Agreement (AEWA), the Ramsar Convention and the work of the Mediterranean Wetlands Observatory (MWO) as an advocacy t...

Scopoli’s Shearwater (Calonectris diomedea) is a Procellariiform endemic to the Mediterranean Basin which is considered to be vulnerable in Europe due to recent local declines and its susceptibility to both marine and terrestrial threats. In the 1970s–1980s, its population size was estimated at 57,000–76,000 breeding pairs throughout the Mediterran...

The use of lead shot for wildfowling is a severe threat to waterbirds through ingestion of toxic lead pellets. Consequently, lead shot has been banned in many countries since the late 1990s and on Tour du Valat estate since 1994 (Camargue, France). An experimental study was undertaken to check if hunters would habituate to this new type of cartridg...

The increases in mute swan (Cygnus olor Gmelin) population size have caused concern among stakeholders, who sometimes consider it as a pest species. Here, we aim to review existing studies on the ecological effects that mute swans have on wetlands. Claim that mute swans threaten other waterbirds were partly supported: mute swans sometimes behave te...

Dans le cadre du Plan national d’actions pour la loutre, l’ONCFS et le Conservatoire d’espaces naturels de Midi-Pyrénées ont coordonné entre 2011 et 2013 une étude visant à caractériser la situation de l’espèce dans cette région. Les résultats indiquent une dynamique de population positive. Les améliorations méthodologiques apportées dans le cadr...

The avifauna of the Obi archipelago is rather poorly studied and current understanding is essentially based on several historic collecting efforts and few recent visits by modern ornithologists, none of which reached the mountains above 750 m. Furthermore, the taxonomic position of many bird populations restricted to the archipelago or shared with...

Richement illustré, ce petit guide de poche permet l’identification de 200 espèces d’oiseaux d’eau présentes du nord du Soudan jusqu’à la Mauritanie, en passant par l’Egypte, la Libye, la Tunisie, l’Algérie et le Maroc. Chaque espèce est présentée avec ses noms arabes vernaculaires utilisés dans les 7 pays, des dessins et des textes d’identificatio...

It's a bilingual book (English/Arabic) reporting the winter distribution of 101 waterbird species on 110 wetlands censused between 2005 and 2010. Maps are provided for each species and ring recoveries are discussed for species such as the Spoonbill (Platalea leucorodia), Greater Flamingo (Phoenicopterus roseus) and Lesser Black-backed Gull (Larus f...

The largest population of Scopoli's Shearwater Calonectris diomedea was previously estimated on Zembra Island, Tunisia at 15,000-25,000 pairs. A distanc e-s ampling survey c onducted in 2009 and 2010 resulted in a new estimate of 141,780 breeding pairs (95 % CI: 113,720-176,750). This results in a re-estimation of the global population size, also s...

Les systèmes insulaires et plus particulièrement les petites îles constituent un patrimoine commun à la Méditerranée dont la gestion conservatoire s’avère prioritaire. Dans toute la Méditerranée, on dénombre près de 15.000 îles et îlots, le seul bassin occidental en compte plus de 1000, toutefois seulement 35 archipels sont officiellement gérés. Le...

Twenty-four wetlands have been designated by the French government as wetlands of international importance for wildfowl (Anatidae sp.) under the Convention on Wetlands of International Importance especially as Waterfowl Habitat (more usually known as the Ramsar Convention). These 24 current and 12 candidate Ramsar sites together cover 3,170,000 ha...

Vingt espèces d’Odonates ont été recensées au cours de prospections réalisées dans la Réserve Nationale de Chasse et de Faune Sauvage d’Orlu (Pyrénées ariégeoises, milieu montagnard : 915-2765 m). Les recherches de larves et exuvies ont permis la récolte de données supplémentaires par rapport aux inventaires d’imagos. Une petite population de Coena...

Species introduction may constitute an important threat to indigenous biodiversity. The naturalization of Brook Trout Salvelinus fontinalis in the Orlu Protected Area (Ariège. France) may affect local communities, especially Odonates. We surveyed the wetlands of this protected area in order to compare the distributions of Odonates and salmonids. Ou...

Systematic surveys of mainly coastal wetlands in Libya were carried out for the first time in January 2005 and 2006, to identify sites of major importance for waterbirds in winter. In 2005, nearly 30,000 waterbirds were found, and in 2006 over 52,000, with large numbers of gulls recorded in both years. The surveys showed that Libyan wetlands are use...

Summary report on an Ornithological Survey in Libya from 19 to 31 January 2006 Hichem Azafzaf, Nicola Baccetti, Pierre Defos du Rau, Habib Dlensi, Mohamed Feisal Essghaier, Khaled Etayeb, Abdulmaula Hamza, Michael Smart 1. Introduction: A first ever comprehensive winter ornithological survey of coastal wetlands in Libya had been carried out in Ja...

The biology of the Jack Snipe Lymnocryptes minimus is poorly known and recent estimates of its population size are contradictory. To encourage ringing and marking studies of this cryptic species, we tested and improved a trapping technique in the Camargue during winter and migration periods. This capture method consists of walking with a horizontal...

Studies describing habitat use in animal species need to take into account detectability of individuals in order to reach more robust conclusions. However, the importance of detectability in habitat selection analyses of rare and cryptic species has received little investigation, although robust methods for estimating detectability have been made r...

The present survey was organized under a Memorandum of Understanding between AEWA, RAC/SPA (the Regional Activities Centre on Specially Protected Areas of the UNEP Mediterranean Action Programme, based in Tunis), and the EGA (Environment General Authority of Libya). The Action Plan for the conservation of bird species listed in Annex II of the Prot...

La Réserve Nationale de Chasse et de Faune Sauvage d’Orlu s’intègre au réseau Natura 2000. Alors que le Document d’objectifs du site est en cours de rédaction, il est aujourd’hui crucial d’identifier les problèmes de gestion qui s’y posent ou s’y poseront à l’avenir et leurs solutions socio-économiques éventuelles. La conservation des prairies suba...

Western European populations of red-crested pochard (Netta rufina) are characterized by low size and high fragmentation, which accentuate their sensitivity to hunting. Uncertainties regarding the demographic trends of these populations highlight the need for pertinent hunting regulations. This requires identification of the limits of the population...