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International audience; We recorded thirty 24-hours monitoring periods with 10-min sampling intervals on 7 (3 female; 4 male) GPS-collared adult free ranging red deer (Cervus elaphus), from June 1999 to December 2000, in the Parc National des Cévennes, France. We observed the duration of resting bouts (n=385) and then microhabitat variables (aspect, slope, presence of edge and litter, visibility, abundance of vegetation consumed or not) at 178 resting places. Resting bouts were shorter during the night than during the day from June to October, but did not vary between sexes. Resting places visibility was lower during the day, especially in August. Daytime resting places generally offered more litter, and fewer consumed plant species. Females used steeper slopes than males. We found higher variability in visibility and slope during the night. Aspect used did not vary from month to month, or between day and night. Observed differences between day and night resting place characteristics suggest that red deer were facing a clear trade-off between feeding and cover. Use of cover prevailed during the daytime whereas night resting place characteristics were more variable, indicating less constrained behaviour. Thus, cover (as a protection from disturbance), as well as food, is an important factor in red deer habitat use (at least during the day in disturbed areas) and should not be neglected in forest carrying capacity management.; Nous avons enregistré 30 suivis de 24h, avec des localisations programmées toutes les 10 minutes, sur 7 cerfs adultes en liberté (3 femelles; 4 mâles), équipés de colliers GPS, de juin 1999 à décembre 2000, dans le Parc National des Cévennes, France. Nous avons étudié la durée des périodes de repos (n=385) ainsi que les variables de microhabitat (exposition, pente, présence de lisière et de litière, visibilité, abondance de végétation consommée ou non) sur 178 places de repos. Les périodes de repos étaient plus courtes la nuit que le jour de juin à octobre, mais ne différaient pas entre sexes. La visibilité était plus faible sur les places de repos diurne, particulièrement en août. Les places de repos diurne présentaient aussi plus de litière et moins de plantes consommées. Les femelles utilisaient des pentes plus fortes que les mâles. Nous avons trouvé une plus forte variabilité de visibilité et de pente pendant la nuit. L'exposition utilisée ne différait ni entre mois, ni entre le jour et la nuit. Les différences observées sur les caractéristiques des places de repos de jour et de nuit suggèrent que les cerfs faisaient face à un compromis évident entre alimentation et couvert. L'utilisation du couvert prévalait durant la journée alors que les caractéristiques des places de repos nocturne étaient plus variables, indiquant moins de contraintes. Ainsi, le couvert (vu comme une protection contre le dérangement), au même titre que la nourriture, est un facteur important de l'utilisation de l'habitat par le cerf (au moins durant la journée dans les zones perturbées) et ne devrait pas être négligé dans l'aménagement de la capacité d'accueil en forêt.

Global Positioning System (GPS) is an important new technology for spatio-temporal behaviour studies of animals. Differential correction improves location accuracy. Previously, it mostly removed partially the influence of Selective Availability (SA). SA was deactivated in May 2000. The aim of this study was to quantify the influence of SA cancellation on location accuracy of various GPS receivers. We tested the accuracy of locations obtained from non-differential and differential GPS animal collars before and after SA removal. We found a significant improvement in accuracy for both types of GPS collars. However, differential GPS still provides more accurate locations.

Eight juvenile (3–8 months) wild boars belonging to two separate litters, and the mother of each litter, were radiolocated daily. The position of an individual juvenile at the time of each location was classified according to its association with its postnatal range, its mother, and its siblings. Preliminary analysis showed that location relative to the postnatal range was independent of association with the mother and siblings, while association with the mother was positively correlated. Although a degree of attachment to their postnatal range persisted in juveniles, surrounding areas were used preferentially. Juveniles were equally likely to be located in the presence of their mother as without her, but they generally separated from their mother during exploratory phases outside the postnatal range. Individual differences in exploratory behaviour occurred between juveniles from the same litter.

International audience; We investigated space-use patterns of the West African savanna buffalo (Syncerus caffer brachyceros), a little-studied subspecies occurring at the northern limit of the African buffalo's geographical range. This buffalo generally ranges in small herds (about 45 individuals) and has a low body mass (approximately 400 kg) relative to the Cape buffalo (S. c. caffer). We monitored the movements of 7 breeding herds in W Regional Park (Burkina Faso, Benin, Niger) using global positioning system collars and activity data loggers. Habitat selection was analyzed at both large (interseasonal) and small (intraseasonal) scales in a context where resources are segregated spatially at some times of year. Both biotic (primary production and vegetation types) and abiotic (timing of rainfall and surface water) covariates, and the extent to which neighboring herds shared space, were considered. In the dry season buffalo herds ranged close (within 5.3 +/- 2.0 km, mean +/- SD) to segments of permanent rivers. At the onset of the monsoon all herds but 1 (which had year-round access to suitable resources) performed a large (35 +/- 10 km) directional movement in response to a large-scale gradient of primary production. Spatiotemporal dynamics of forage and water resources thus jointly stimulated interseasonal directional movements and shaped large (335 +/- 167 km(2)) annual home ranges. Furthermore, the establishment of home ranges in the wet season appears to be conditioned by a threshold (about 10%) in the availability of perennial grasses. Habitat-selection analysis at intraseasonal scale also underlines the key role played by perennial grasses for buffaloes. The spatial arrangements of home ranges of neighboring herds also suggest that interherd behavioral avoidance is a high-level constraint on foraging processes. The ability of the African buffalo to cope with contrasting environmental conditions throughout most sub-Saharan ecosystems highlights the high behavioral plasticity of this species.

International audience; Using data from a global positioning system (GPS), seven adult red deer (Cervus elaphus L.) were tracked in the Parc National des Cévennes, southern France, between November 1998 and December 2000 to assess the factors affecting large-range movement patterns and habitat use. The home range varied from a single compact area for females to three distinct seasonal ranges for males, which used alternative migratory strategies (i.e. non-, downward- and upward-migrants). The migrants used mainly southerly and easterly aspects, and wintered in areas having steeper slopes than were used during summer or the rut season. For males, the time of rut migration was mid-September and they finally entered wintering ranges from mid-December to the beginning of January. Exploratory behaviour (i.e. individuals found outside the limits of their familiar area but returning to it a few days later) occurred in both sexes and for all individuals monitored during at least a 6-month period. Velocity and efficiency of exploratory movements were higher than usual movements. During these exploratory movements, hinds may have used different landscape attributes (elevation, slope, canopy cover) while stags did not. These results provide new empirical information that could be used for building and applying broad-scale spatial and landscape use models in ecological research.

Movement and activity of free-roaming wild boar were studied in a hunted forest area. Thirty-six 24-h radio-tracking sessions were conducted on 2 sets: 5 subadult males (26 sessions) and 4 breeding females (10 seesions).

International audience; To determine the performance of Global Positioning System (GPS) for habitat studies in free-ranging animals, we tested differential 6- and 8-channel GPS collars under six representative canopies and one open-field reference site in the 'Parc national des Cevennes'. Southern France. The proportion of successful locations decreased under taller trees and worsened with snow accumulation in mixed coniferous habitats. The mean location Success of seven free-ranging red deer fitted with 6-channel GPS collars in the same study area increased with a shorter interval between location attempts and during the leaf-off period. Our data suggested that the differences in location success between leaf-on and leaf-off periods might reflect shifts in habitat use rather than a leaf effect under deciduous trees; Performances de colliers GPS différentiels en forêt de montagne tempérée. Pour évaluer les performances des colliers GPS utilisés dans les études sur l’utilisation de l’habitat par les animaux sauvages, nous en avons testé deux types (6 et 8 canaux) dans six peuplements forestiers de montagne tempérée et en milieu ouvert. La proportion de localisations réussies par les GPS diminue lorsque la taille des arbres augmente ainsi que sous les peuplements de conifères lorsqu’ils sont couverts de neige. La proportion de localisations réussies, recueillies dans les mêmes milieux sur sept cerfs élaphes équipés de colliers GPS 6 canaux, augmente quand l’intervalle de temps entre les localisations est plus court, et quand les arbres sont dépourvus de feuilles. Nos résultats laissent à penser qu’il s’agit là plus de la conséquence d’un changement d’habitat par l’animal qu’un effet lié à la présence ou à l’absence des feuilles

International audience; Differential Global Positioning System technology can provide series of accurate locations of free-ranging animals with a short, fixed interval. The sum of straight-line distances between valid locations (y) plotted against number of attempted fixes per day (x) should fit a hyperbolic function (i.e., y = x/[ax - b]) after removing inaccurate fixes and inactive periods. Its asymptotic value (1/a) can provide an estimate of real travel distance. The ratio of 1/a and y is a correction factor to apply to perceived straight-line distance to estimate real distance traveled. We achieved a good model fit on free-ranging adult red deer (Cervus elaphus) from data obtained every 15 min for a male and a female in winter 1997-1998, with a narrow range of correction factors. To validate this model, we used independent datasets from 3 other adult red deer roaming in the same area in winter 2000. We applied the procedure to distances perceived with fixed intervals ranging from 30 to 240 min and found consistent results in estimated real distances. Application of various steps of this analytical method could further development of a general approach to assess real distance traveled by individuals, thus offering new ways of studying habitat use or energetic requirements

L’agnelage en plein air intégral a été observé pendant 4 années dans un troupeau d’une cinquantaine de brebis Lacaune élevées sur le Causse du Larzac (Aveyron). Le taux de mortalité des agneaux à 48 h s’élève à 24 %. Dans ces conditions, 33,5 % de cette mortalité sont attribués à des causes physiques ou biologiques relatives aux mères et aux nouveau-nés, 38,5 % au comportement des mères et 12 % aux rigueurs des conditions météorologiques, 16 % des causes de mortalité restent inconnues. Parmi les 38,5 % des causes de mortalité dues au comportement des mères, le non isolement pre-partum occasionne 7 % de mortalité ; cette cause de mortalité affecte plutôt les agneaux des femelles primipares qui, s’éloignant en moins grand nombre que les femelles multipares pour mettre bas, sont dérangées par la présence du troupeau au moment de la reconnaissance de leur agneau. Par contre, le comportement d’isolement expose les nouveau-nés à la prédation et/ou favorise leur disparition, provoquant 5 % de mortalité. Cette cause de mortalité affecte plutôt les agneaux nés de femelles multipares (puisqu’elles s’isolent plus que les femelles primipares) ainsi que ceux des portées doubles. Enfin 26,5 % de la mortalité due au comportement des mères résultent de troubles de comportement maternel qui conduisent au rejet-abandon des nouveau-nés ; cette cause de mortalité concerne 8 fois plus les agneaux des femelles primipares. La mortalité moyenne due aux conditions météorologiques est de 12 %. En fait ce taux de mortalité est très variable, il fluctue selon les années en fonction des aléas climatiques entre 0 et 27 %. Ainsi, même si par vent fort ( ≥ 3 m/s), plus de la moitié des brebis se réfugient, pour mettre bas à l’abri, dans des zones arbustives, cette utilisation d’abris ne suffit pas à protéger les nouveau-nés lorsque ce vent fort est accompagné de pluies intenses. C’est ainsi que le taux de mortalité dû aux intempéries triple les années où sont réunies un maximum de conditions climatiques rigoureuses.

Communication au colloque de Nancy; National audience

National audience

National audience

National audience