Blanc L.,CNRS Center of Evolutionary and Functional Ecology |
Marboutin E.,Office National de la Chasse et de la Faune Sauvage |
Gatti S.,Office National de la Chasse et de la Faune Sauvage |
Gimenez O.,CNRS Center of Evolutionary and Functional Ecology
Journal of Wildlife Management | Year: 2013
Effective conservation and management require reliable monitoring methods and estimates of abundance to prioritize human and financial investments. Camera trapping is a non-invasive sampling method allowing the use of capture-recapture (CR) models to estimate abundance while accounting for the difficulty of detecting individuals in the wild. We investigated the relative performance of standard closed CR models and spatially explicit CR models (SECR) that incorporate spatial information in the data. Using simulations, we considered 4 scenarios comparing low versus high detection probability and small versus large populations and contrasted abundance estimates obtained from both approaches. Standard CR and SECR models both provided minimally biased abundance estimates, but precision was improved when using SECR models. The associated confidence intervals also provided better coverage than their non-spatial counterpart. We concluded SECR models exhibit better statistical performance than standard closed CR models and allow for sound management strategies based on density maps of activity centers. To illustrate the comparison, we considered the Eurasian lynx (Lynx lynx) as a case study that provided the first abundance estimates of a local population in France. © The Wildlife Society, 2012.
Peron G.,Colorado State University |
Ferrand Y.,Office National de la Chasse et de la Faune Sauvage |
Leray G.,Office National de la Chasse et de la Faune Sauvage |
Gimenez O.,CNRS Center of Evolutionary and Functional Ecology
Biological Conservation | Year: 2013
The population dynamics of waterbirds constitute an indicator of wetland conservation status. However, waterbird population censuses are difficult to implement because the individuals are very mobile within their range, and some species are elusive or breed in remote areas. Therefore, demographic models based on the estimation of survival and breeding success appear as a reliable alternative to population censuses. Here we present this model-based approach in the case of the French-wintering snipe population (Gallinago gallinago), which breeds mainly in Northern and Eastern Europe. Using a multi-state model to accommodate the mobile nature of waterbirds, we estimate snipe survival using a joint analysis of capture-recapture and ring-recovery data. Then, we use matrix population models to estimate the minimum recruitment rate required to maintain the population at its current size and derive a chart for using age-ratio of ringed birds as indicator of population trend. Although we call for more data collection in order to reduce uncertainty, we conclude that occasional declines are likely after years with poor breeding success, but that the French-wintering snipe population is on average stable. Individual-based monitoring data and population modeling make it possible to use waterbirds as indicator species at the flyway scale. © 2013 Elsevier Ltd.
Gaillard J.-M.,University Claude Bernard Lyon 1 |
Mark Hewison A.J.,French National Institute for Agricultural Research |
Klein F.,Office National de la Chasse et de la Faune Sauvage |
Plard F.,University Claude Bernard Lyon 1 |
And 3 more authors.
Ecology Letters | Year: 2013
How populations respond to climate change depends on the interplay between life history, resource availability, and the intensity of the change. Roe deer are income breeders, with high levels of allocation to reproduction, and are hence strongly constrained by the availability of high quality resources during spring. We investigated how recent climate change has influenced demographic processes in two populations of this widespread species. Spring began increasingly earlier over the study, allowing us to identify 2 periods with contrasting onset of spring. Both populations grew more slowly when spring was early. As expected for a long-lived and iteroparous species, adult survival had the greatest potential impact on population growth. Using perturbation analyses, we measured the relative contribution of the demographic parameters to observed variation in population growth, both within and between periods and populations. Within periods, the identity of the critical parameter depended on the variance in growth rate, but variation in recruitment was the main driver of observed demographic change between periods of contrasting spring earliness. Our results indicate that roe deer in forest habitats cannot currently cope with increasingly early springs. We hypothesise that they should shift their distribution to richer, more heterogeneous landscapes to offset energetic requirements during the critical rearing stage. © 2013 John Wiley & Sons Ltd/CNRS.
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: KBBE-2008-1-3-03 | Award Amount: 4.43M | Year: 2009
Although classical swine fever (CSF) has been eradicated in wide areas within the EU the disease is endemic in some new member states particularly in back yard pigs. In order to improve the eradication strategies the project aims are a) the final development and testing of a live marker vaccine candidate for the prevention and improved control of CSF, both orally and intramuscularly applicable; b) the development and optimisation of accompanying discriminatory diagnostic tests; c) the production of an effective, oral delivery system for the marker vaccine for use in wild boar and back yard pigs; d) the easy selection of diseased animals. The improved knowledge on immunological reactions and pathogenesis will support a more efficient vaccine application and provide data for the epidemiological models. Epidemiological studies of CSF in domestic and back yard pigs and in wild boar including molecular epidemiology intend to increase the insight of CSF transmission and persistence. Epidemiological models will be developed to support risk assessment as well for conventional eradication strategies as for new strategies using the new vaccines and diagnostic tools including the role of CSF reservoirs. The results concerning anti-viral treatment will be evaluated and compared with the traditional eradication strategies.
Benoist S.,Center National Detudes Et Of Recherche Appliquee Sur La Faune Of Montagne |
Garel M.,Center National Detudes Et Of Recherche Appliquee Sur La Faune Of Montagne |
Cugnasse J.-M.,Office National de la Chasse et de la Faune Sauvage |
Blanchard P.,CNRS Biological Evolution and Diversity Laboratory
PLoS ONE | Year: 2013
In prey species, vigilance is an important part of the decision making process related to predation risk effects. Therefore, understanding the mechanisms shaping vigilance behavior provides relevant insights on factors influencing individual fitness. We investigated the role of extrinsic and intrinsic factors on vigilance behavior in Mediterranean mouflon (Ovis gmelini musimon6Ovis sp.) in a study site spatially and temporally contrasted in human pressures. Both sexes were less vigilant in the wildlife reserve compared to surrounding unprotected areas, except for males during the hunting period. During this period, males tended to be less strictly restricted to the reserve than females what might lead to a pervasive effect of hunting within the protected area, resulting in an increase in male vigilance. It might also be a rutting effect that did not occur in unprotected areas because males vigilance was already maximal in response to human disturbances. In both sexes, yearlings were less vigilant than adults, probably because they traded off vigilance for learning and energy acquisition and/or because they relied on adult experience present in the group. Similarly, non-reproductive females benefited of the vigilance effort provided by reproductive females when belonging to the same group. However, in the absence of reproductive females, non-reproductive females were as vigilant as reproductive females. Increasing group size was only found to reduce vigilance in females (up to 17.5%), not in males. We also showed sex-specific responses to habitat characteristics. Females increased their vigilance when habitat visibility decreased (up to 13.8%) whereas males increased their vigilance when feeding on low quality sites, i.e., when concomitant increase in chewing time can be devoted to vigilance with limited costs. Our global approach was able to disentangle the sex-specific sources of variation in mouflon vigilance and stressed the importance of reserves in managing and conserving wild sheep populations. © 2013 Benoist et al.
Guillemain M.,Office National de la Chasse et de la Faune Sauvage
Wildlife Biology | Year: 2010
Many ringing programmes rely heavily on rings returned by hunters, yet the motivation of hunters to participate in such schemes has not so far been examined. A questionnaire survey was launched while French hunters reported hunted teal Anas crecca rings. The main aim was to quantify the proportion of rings returned by different means, to ask hunters about their previous knowledge of the ringing programme and about their motivation to report rings. Hunters reporting rings exhibited altruistic behaviour, sending their data with little knowledge of what they will be used for, and indicated their willingness to help research as their main motivation. They showed little interest in an internet-based ring return system or internet information, but relied mostly on a phone-reporting system when the phone number was indicated on nasal saddles (although the sole presence of a nasal saddle in addition to a metal ring also likely improved the reporting rate of such marked birds). Considering these sociological aspects in the advertisement of ringing programmes may help improve ring recovery rates of quarry species. © 2010 Wildlife Biology, NKV.
Girard O.,Office National de la Chasse et de la Faune Sauvage
Alauda | Year: 2012
From 1994 to 2009, 7,816 dead birds belonging to 92 species were sampled on roads in Atlantic France mainly in the Vendée region. Barn Owl, Common Moorlien, Blackbird and House Sparrow were the most involved species. The highest mortality rate was found in June and December and the lowest In April-May and July-August. More of 50% of the corpses have been found along hedge-lined roads. The influence of weather conditions on road mortality is difficult to assess, except for a few species (Robin, Thrushes, Chaffinch) whose mortality was higher during cold spells. About 55% of birds were killed during day-time. We tried to estimate the annual road mortality in birds for the whole of France by using three approaches. Thus it is likely that at least some 30 millions of birds are killed each year by road traffic in France. Besides predation by cats, road traffic may be considered as the second most important non-natural cause of bird mortality in that country.
Girard O.,Office National de la Chasse et de la Faune Sauvage
Alauda | Year: 2012
During the first half of February 2012 a severe and sudden cold spell occurred in France. Surveys by car and by walking (mainly in the Vendée region in West France) allowed to determine the number of dead birds found to amount 1,300-1,700 individuals/100km. These birds died either by collision with cars or by starvation or contacts with salt spread on roads. The Northern Lapwing was the main species involved (1,200-1,500 individuals/100km) followed by Common Blackbird, Song Thrush and Redwing. A very high mortality of some raptors was also observed.
Broyer J.,Office National de la Chasse et de la Faune Sauvage |
Curtet L.,Office National de la Chasse et de la Faune Sauvage
Hydrobiologia | Year: 2012
Fishponds are artificial ecosystems in which biodiversity may be strongly affected by fish farming management. We studied biodiversity variation along a gradient of fish farming intensification within a 180-pond sample of a French region to establish whether biodiversity primarily depended on extensive management with the alternative hypothesis that some habitat characteristics could compensate for the effect of intensification. We compared the relationships of three biodiversity indicators (breeding birds, protected plants, macrophytes) to an index of intensification and to habitat characteristics likely to influence each indicator. In all selected indicators, species richness did not vary according to the composite intensification gradient. Protected plant richness was best explained by periodic drainage, which could thus benefit biodiversity in intensified fishponds provided that shallow littoral areas are still present. Bird richness was linked to macrophyte cover and probably to reed bed areas. Macrophyte richness and coverage were negatively influenced by low water transparency and high fish biomass which seemed likely to affect bird habitat above 350-400 kg/ha. Aquatic vegetation, which may reflect interactive effects of environmental factors and fish farming management, may then contribute to assessment of the ecological status of fishponds under the E. U. Water Framework Directive. © 2012 Springer Science+Business Media B.V.
Broyer J.,Office National de la Chasse et de la Faune Sauvage
Bird Study | Year: 2011
Capsule Mowing postponement in 25% of a meadow system may lead to improved but instable population dynamics in meadow birds. Aim To monitor the long-term effects of mowing postponement on the abundance and territory density of meadow passerines in 25% of a 3000-ha hay-meadow area in the Saone Valley (eastern France). Methods From 1993 to 2009, passerine abundance was measured annually in 78 plots using point counts and territory density was assessed in two study areas by Territory Mapping. Results The programme of mowing postponement led to substantially increased passerine abundance and territory density, with the highest increase detected in Whinchats Saxicola rubetra. No positive trend was observed in Corn Buntings Emberiza calandra. Immediately after the increase in abundance, bird distribution within the study area was not influenced by the timing of mowing. The hatching success, assessed by the systematic observation of food carrying, was negatively influenced by early mowing (40% recorded when 60% of the meadow area was already harvested on 1 July) or, in late mown areas, by high meadow passerine territory density (40% when territory density was 10 per 10 ha). Hatching rate was usually higher in Whinchats than in Corn Buntings. Conclusion By improving meadow passerine breeding outputs and density, mowing postponement led to instable population dynamics with dominance of certain species and density-dependent breeding success. © 2011 British Trust for Ornithology.