Augiron S.,Societe dEtudes Scientifiques Independante |
Augiron S.,CNRS Chizé Center for Biological Studies |
Gangloff B.,CNRS Chizé Center for Biological Studies |
Brodier S.,CNRS Chizé Center for Biological Studies |
And 10 more authors.
Journal of Arid Environments | Year: 2015
The Montagu's Harrier (MH) and the Lesser Kestrel (LK) are two threatened raptors overwintering in the Sahel. To ensure their conservation, it is essential to gain better knowledge on their winter ecology in order to predict their spatial distribution and estimate their respective population sizes. Combining information on raptors, their prey and habitats, collected over the 2009-2013 period in a 17,000km2 study area located in central Senegal, we assessed spatio-temporal variations of grasshopper density, and consequently estimated the abundance and distribution of MHs and LKs. The distribution of grasshoppers highlighted areas with contrasted densities, declining along a North East/South West gradient which constrained the spread of raptors. Moreover both species selected heterogeneous landscapes of savannah, mixing semi-natural and anthropogenized habitats. Population size reached 3360 and 36,000 individuals for MH and LK, which represents ~5% and 50% of their European breeding populations. The challenge for their conservation resides in their use of habitats suffering from anthropogenic perturbations, both during breeding and wintering. In Africa, this situation will be exacerbated in the near future due to interactions between food security, implying the control of grasshopper outbreaks and agricultural intensification, and to ongoing climate changes. © 2014 Elsevier Ltd.
Mihoub J.-B.,University Pierre and Marie Curie |
Gimenez O.,CNRS Center of Evolutionary and Functional Ecology |
Pilard P.,LPO Mission Rapaces |
Sarrazin F.,University Pierre and Marie Curie
Biological Conservation | Year: 2010
In the context of attested global changes, accurate estimation of whether climatic fluctuations impact on population demographic parameters is needed for adequate management, especially for migratory species. We present a capture-recapture analysis linking survival rates of the vulnerable Lesser Kestrel (Falco naumanni) to annual rainfalls in the Sahel region, considered as a proxy of climatic conditions on wintering grounds. Recapture data were obtained from field observations of individuals ringed and sexed as juveniles over a 14-year monitoring period (1994-2007). We addressed a common but problematic situation in birds where: (i) sex is known with certainty for first-summer or older birds but only suspected for juveniles, and (ii) a large proportion of individuals never return to the study population (e.g. transient behavior). Transient behavior and unknown sexes were explicitly integrated considering a two age class in a multistate capture-recapture model. Survival was time-varying for juveniles (geometric mean: 0.499 ± 0.021) but constant - and higher - for adults (0.718 ± 0.013). Yearling survival probabilities were strongly correlated with rainfalls in the Sahel, suggesting a high dependence of juvenile upon the wintering conditions. While taking sex uncertainty into account, we detected no sex-dependence in survival. Incorporating the sensitivity of survival of wintering migratory birds to climatic variables such as precipitations in arid Sahelian ecosystem may allow to model conservation scenarios with a greater realism. Finally, we encourage the development of international management strategies for migratory species on wintering areas in addition to the existing conservation actions on summering Mediterranean grounds. © 2010 Elsevier Ltd. All rights reserved.
Night roosts of the Egyptian Vulture Neophron percnopterus in the Basque country in 2013 [Observation des dortoirs de vautours percnoptères Neophron percnopterus au pays basque au cours de l'année 2013]
Clouet M.,55 avenue des Capucines |
Gonzalez L.,Association SAIAK |
Kobierzycki E.,LPO Mission Rapaces |
Alauda | Year: 2014
The two communal roosts of Egyptian Vulture known in France are located in the Basque country where the birds are recorded while perching on dead trees. Counts were conducted on 32 visits at dawn and/or dusk between April and September 2013. The highest numbers were found in August with 36-40 individuals, a maximum not related to food availability. Adults and sub-adults were always the most abundant individuals while immature birds (1-3 years old) never accounted for more than 30 % of the birds present. Comparison with former years showed a decrease involving mainly immature birds. We suggest that camera trapping and GPS telemetry tracking are necessary in the future to improve our knowledge about the role played by these roosts in the species' dynamic and behaviour.
Coeurdassier M.,University of Franche Comte |
Riols R.,LPO Auvergne |
Decors A.,British Petroleum |
Mionnet A.,LPO Champagne Ardenne |
And 6 more authors.
Conservation Biology | Year: 2014
In Europe, bromadiolone, an anticoagulant rodenticide authorized for plant protection, may be applied intensively in fields to control rodents. The high level of poisoning of wildlife that follows such treatments over large areas has been frequently reported. In France, bromadiolone has been used to control water voles (Arvicola terrestris) since the 1980s. Both regulation and practices of rodent control have evolved during the last 15 years to restrict the quantity of poisoned bait used by farmers. This has led to a drastic reduction of the number of cases of poisoned wildlife reported by the French surveillance network SAGIR. During the autumn and winter 2011, favorable weather conditions and high vole densities led to the staging of several hundreds of Red Kites (Milvus milvus) in the Puy-de-Dôme department (central France). At the same time, intensive treatments with bromadiolone were performed in this area. Although no misuse has been mentioned by the authorities following controls, 28 Red Kites and 16 Common Buzzards (Buteo buteo) were found dead during surveys in November and December 2011. For all these birds, poisoning by bromadiolone as the main cause of death was either confirmed or highly suspected. Other observations suggest a possible impact of bromadiolone on the breeding population of Red Kites in this area during the spring 2011. French regulation of vole control for plant protection is currently under revision, and we believe this event calls for more sustainable management of rodent outbreaks. Based on large-scale experiments undertaken in eastern France, we propose that direct control of voles at low density (with trapping or limited chemical treatments) and mechanical destruction of vole tunnels, mole control, landscape management, and predator fostering be included in future regulation because such practices could help resolve conservation and agricultural issues. © 2014 Society for Conservation Biology.
Rodriguez A.,CSIC - Doñana Biological Station |
Alcaide M.,Harvard University |
Negro J.J.,CSIC - Doñana Biological Station |
Pilard P.,LPO Mission Rapaces
Animal Conservation | Year: 2011
Gathering knowledge about the migratory routes and wintering areas of threatened populations is fundamental for their successful conservation. Here, we used a non-invasive approach that relies on major histocompatibility complex (MHC) polymorphism to infer the breeding origin of a long-distance migratory bird, the lesser kestrel Falco naumanni, in its most important wintering quarters in the Sub-Saharan Africa (Senegal and South Africa). Private alleles support a strong connectivity between wintering Senegalese and western European breeding populations. On the other hand, birds wintering in South Africa were genetically differentiated with respect to western European breeding populations and might therefore gather individuals from the eastern distribution range. This study demonstrates that, at least at wide continental scales, MHC genes can be powerful intrinsic markers to study migration and migration connectivity, thus adding value to its role in conservation and management. © 2011 The Authors. Animal Conservation © 2011 The Zoological Society of London.
Mihoub J.B.,CNRS Science Conservation Center |
Mouawad N.G.,CNRS Science Conservation Center |
Pilard P.,LPO Mission Rapaces |
Jiguet F.,CNRS Science Conservation Center |
And 2 more authors.
Journal of Avian Biology | Year: 2012
Adjusting breeding phenology to climate fluctuations can be problematic for migratory birds as they have to account for local environmental conditions on the breeding grounds while migrating from remote wintering areas. Predicting general responses to climate change is not straightforward, because these responses vary between migrant species due to the species-specific ecological drivers of breeding behaviour. Therefore more information is needed on species with different ecological requirements, including data on heritability of migration, factors driving phenological changes and how climate affects selection pressures. Here, we measure heritability in settlement dates and the effect of local climate at the breeding grounds on settlement dates, reproductive success and selection patterns in a French population of a trans-Saharan migratory insectivorous raptor, the lesser kestrel Falco naumanni, monitored and ringed since 1996. Heritability of settlement dates was low (0.07±0.03), indicating a weak evolutionary potential. Nevertheless, plasticity in settlement dates in response to temperatures allowed earlier settlement when early spring was warmer than average. Reproductive success and selection patterns were strongly affected by temperature during settlement and chick rearing respectively. Warmer spring decreased selection for earlier settling and warmer early summer increased reproductive success. Interestingly, selection for earlier settling was more intense in cooler springs, contrasting with patterns from passerines lagging behind food peaks. Altogether, these results suggest a positive effect of warmer temperatures on breeding performances of lesser kestrels most likely because the French population is at the coolest boundary of the species European breeding range. © 2012 The Authors. Journal of Avian Biology © 2012 Nordic Society Oikos.