Diagnosing Mechanisms of Decline and Planning for Recovery of an Endangered Brown Bear (Ursus arctos) Population

Background: The usual paradigm for translocations is that they should not take place in declining populations until the causes(s) of the decline has been reversed. This approach sounds intuitive, but may not apply in cases where population decline is caused by behavioral or demographic mechanisms that could only be reversed by translocation itself. Methodology/Principal Findings: We analyzed a decade of field data for Pyrenean brown bears (Ursus arctos) from two small populations: the growing Central population- created from a previous translocation and the endemic Western population- believed to be declining because of excessive human-caused mortality. We found that adult survival rates for both populations were as high as those observed for most other protected brown bear populations. However, the Western population had much lower reproductive success than the Central population. Adult breeding sex ratio was male-biased in the Western population and female-biased in the Central population. Our results exclude high anthropogenic mortality as a cause for population decline in the West but support low reproductive success, which could result from sexually selected infanticide induced by a male-biased adult sex ratio or inbreeding depression. Using a stochastic demographic model t

Reciprocal modulation of internal and external factors determines individual movements

Summary 1. Movement is fundamental to individual and population dynamics, as it allows individuals to meet their basic requirements. Although movement patterns reflect interactions between internal and external factors, only few studies have examined the effects of these factors on movement simultaneously, and they generally focused on particular biological contexts (e.g. dispersal, foraging). 2. However, the relative importance of these factors in driving individual routine movements might reflect a species' potential flexibility to cope with landscape changes and therefore buffer their potential impact on fitness. 3. We used data from GPS collars on Scandinavian brown bears to investigate the relative role of these factors, as well as an additional factor (period of the year) on routine movements at two spatial scales (hourly and daily relocations). 4. As expected, internal factors played a major role in driving movement, compared to external factors at both scales, but its relative importance was greater at a finer scale. In particular, the interaction between reproductive status and period of the year was one of the most influential variables, females being constrained by the movement capacity of their cubs in the first periods of the year. The effect of human disturbance on movement was also greater for females with cubs than for lone females. 5. This study showed how reciprocal modulation of internal and external factors is shaping space use of brown bears. We stress that these factors should be studied simultaneously to avoid the risk of obtaining context-dependent inferences. Moreover, the study of their relative contribution is also highly relevant in the context of multiple-use landscapes, as human activities generally affect the landscape more than they affect the internal states of an individual. Species or individuals with important internal constraints should be less responsive to changes in their environment as they have less freedom from internal constraints and should thus be more sensitive to human alteration of the landscape, as shown for females with cubs in this study

Autonomie et activite de surveillance chez le sanglier (Sus Scrofa): approche descriptive, experimentale et evolutive

Available from INIST (FR), Document Supply Service, under shelf-number : TD 83642 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Importance of movement constraints in habitat selection studies.

Ecological niche Movement paths Trajectories Ursus arctos Habitat selection a b s t r a c t The aim of this study is to empirically illustrate the importance of taking movement constraints into account when testing for habitat selection with telemetry data. Global Positioning System relocations of two Scandinavian brown bears were used to compare the results of two different tests of habitat selection by the bears within their home range. Both relied on the comparison of observed dataset with datasets simulated under the hypothesis of random habitat use. The first analysis did not take movement constraints into account (simulations were carried out by randomly distributing a set of points in the home range) whereas the second analysis accounted for these constraints (simulations were carried out by building random trajectories in the home range). The results for the two analyses showed contrasted results. Therefore, not accounting for movement constraints in analyses may result in a misleading biological interpretation. Autocorrelation between relocations is not undesirable: it contains information about ecological processes that should be integrated in habitat selection analyses. © 2007 Elsevier B.V. All rights reserved. Introduction During the last decade, the Global Positioning System (GPS) has been used increasingly by biologists to study the habitat selection by animals. The study of habitat selection with this kind of data implies a comparison between the habitat used by this animal and a null model describing the habitat that would have been used under the hypothesis that no habitat selection occurs (random habitat use

Spatiotemporal depredation hotspots of brown bears, Ursus arctos, on livestock in the Pyrenees, France

International audienceOne of the main factors limiting the acceptance of large carnivores is livestock depredation. Reducing damages on livestock requires understanding how depredation varies in space and time. The conservation of the brown bear (Ursus arctos) population in the Pyrenees offers a relevant study case to illustrate this issue, with a minimum population size of 41 individuals recorded in 2016 and an average of 103.3 ± 18.9 attacks per year on domestic animals between 2010 and 2016 during the summer pasture period. We analysed the spatial aggregation of depredation events by using the local Getis-Ord analysis of spatial dependence at the management scale (pastoral units) and at a finest scale (250 × 250 m grain). Our results uncover the absence of coldspots of brown bear depredation in the French Pyrenees and the presence of significant hotspots. Depredation hotspots are consistent in time, meaning that a hotspot in one year is likely to exist in the following year(s). The fine scale analysis allowed identifying both inter-and intra-pasture hotspots and we propose a simple method to rescale these fine scale results. We linked this spatial pattern of hotspots (at 250 m resolution) to environmental factors. Hotspot presence is characterized by being close to forest and buildings with a high proportion of grassland and on steep slopes. Moreover, a nonlinear relationship with brown bear activity describes the presence of hotspots. The assessment of depredation hotspots and their link with environmental factors offers some practical guidance about where to focus efforts in order to decrease this human-large carnivore conflict

Data from: High-throughput microsatellite genotyping in ecology: improved accuracy, efficiency, standardization and success with low-quantity and degraded DNA

Microsatellite markers have played a major role in ecological, evolutionary and conservation research during the past 20 years. However, technical constrains related to the use of capillary electrophoresis and a recent technological revolution that has impacted other marker types have brought to question the continued use of microsatellites for certain applications. We present a study for improving microsatellite genotyping in ecology using high-throughput sequencing (HTS). This approach entails selection of short markers suitable for HTS, sequencing PCR-amplified microsatellites on an Illumina platform and bioinformatic treatment of the sequence data to obtain multilocus genotypes. It takes advantage of the fact that HTS gives direct access to microsatellite sequences, allowing unambiguous allele identification and enabling automation of the genotyping process through bioinformatics. In addition, the massive parallel sequencing abilities expand the information content of single experimental runs far beyond capillary electrophoresis. We illustrated the method by genotyping brown bear samples amplified with a multiplex PCR of 13 new microsatellite markers and a sex marker. HTS of microsatellites provided accurate individual identification and parentage assignment and resulted in a significant improvement of genotyping success (84%) of faecal degraded DNA and costs reduction compared to capillary electrophoresis. The HTS approach holds vast potential for improving success, accuracy, efficiency and standardization of microsatellite genotyping in ecological and conservation applications, especially those that rely on profiling of low-quantity/quality DNA and on the construction of genetic databases. We discuss and give perspectives for the implementation of the method in the light of the challenges encountered in wildlife studies

De l’individu à la population – en passant par l’ontogenèse et l’Umwelt

Poussé par quelques étudiants préférant observer le bouquetin ibérique et l’isard en nature plutôt que le grillon en laboratoire, Raymond Campan commence une incursion dans le domaine de l’éco-éthologie des grands herbivores à la fin des années 70. En 1986, il devient directeur de l’Institut de Recherche sur les Grands Mammifères (IRGM), une unité principalement composé d’agents INRA étudiant l’écologie de la faune sauvage, mais qui accueillera désormais des étudiants formés à l’étude du comportement animal, dont nous aurons la chance de faire partie. En devenant directeur de l’IRGM, Raymond introduit un thème de recherche assez vague mais fédérateur, « De l’individu à la population », parfois décliné en « Contribution des stratégies individuelles à la dynamique des populations » ou en « Contribution de la variabilité interindividuelle à la dynamique des populations ». Ce thème était une invitation à l’analyse des traits d’histoire de vie, et à l’étude de la contribution à la dynamique des populations de ce que l’on nomme aujourd’hui « les personnalités ». Mais il était aussi une invitation à étudier trois aspects de l’éco-éthologie qui, dans l’esprit de Raymond, n’étaient pas nécessairement aussi compatibles avec le néo-darwinisme : les phénomènes d’émergence collective, le développement du comportement et le monde propre de l’individu. Raymond ne proposait pas de théorie toute faite à ce sujet, mais les pistes qu’il nous a indiquées et les échanges que nous avons entretenus avec lui durant nos années de thèse ont largement contribué à la façon dont nous percevons, encore aujourd’hui, le vivant et son évolution