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By regulating successional dynamics in Canada's boreal forest, fires can affect the distribution of the Threatened woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). Caribou tend to avoid areas burned within the last 40 years; however, few studies have compared pre-fire and post-fire caribou observations. In this study, we used caribou GPS locations from the Boreal Shield of Saskatchewan, Canada, to assess the short-term response of caribou to areas that burned while they were collared (hereafter recent burns). We used a 'before-after, control-impact' design to compare the overlap of pre-fire and post-fire seasonal home ranges to the overlap of year-to-year seasonal home ranges. Caribou rarely encountered recent burns and when they did, they adjusted their space use in variable and complex ways that were largely indistinguishable from regular, interannual variation. Caribou tended to reduce use of recent burns in summer-autumn and winter, but not during the calving season, in some cases shifting their home range to incorporate more burned habitat. We conclude that recently burned areas ( Key words: boreal forest, caribou, fire, habitat disturbance, home range, Rangifer tarandus, space use. En regulant la dynamique de succession dans la foret boreale du Canada, le feu peut influer sur la repartition du caribou des bois (Rangifer tarandus caribou (Gmelin, 1788)), une espece menacee. Si les caribous ont tendance a eviter les secteurs brules au cours des 40 annees precedentes, peu d'etudes ont toutefois compare les observations de caribous avant et apres un feu. Nous utilisons des emplacements de caribous obtenus par GPS dans le bouclier boreal de la Saskatchewan (Canada) pour evaluer la reaction a court terme des caribous a des zones brulees alors qu'ils etaient dotes d'un collier (des<< brulis recents >>). Nous employons un schema<>pour comparer le chevauchement des domaines vitaux saisonniers avant et apres le feu au chevauchement des domaines vitaux saisonniers d'une annee a l'autre. La frequence des rencontres de brulis recents par des caribous est faible et, quand elles se produisent, les caribous ajustent leur utilisation de l'espace de manieres variees et complexes qui sont difficiles a departager de la variation interannuelle normale. Les caribous ont tendance a moins utiliser les brulis recents en ete-automne et en hiver, mais non durant la saison de mise bas, deplacant dans certains cas leur domaine vital pour y integrer plus d'habitat brule. Nous concluons que les brulis recents ( Mots-cles: foret boreale, caribou, feu, perturbation de 1'habitat, domaine vital, Rangifer tarandus, utilisation de l'e space., Introduction Global ecosystems are experiencing accelerated rates of change as the frequency, extent, and intensity of natural and human disturbance increases (IPBES 2019). Habitat disturbance is contributing to population declines [...]

Structure in sociality is known to relate to intrinsic and extrinsic factors. Less understood are the mechanics of sociality expressed as fine-scale behaviours that maintain hierarchies, mediate competition, or transmit pathogens. A recent novel approach to quantifying fine-scale social behaviour has been to use proximity-logging biotelemetry collars. This technology continuously records data whenever collars are within a predefined distance of each other, at times of day, and in habitats where traditional ethological approaches to focal-individual sampling of behaviours are unfeasible. We tested a series of expectations on fine-scale ([less than or equal to] 1.4 m) interaction rates and durations consistent with competing hypotheses of seasonal and sexual segregation for elk (Cervus canadensis Erxleben, 1777). Female-female dyads interacted 4 times more frequently than male-male dyads (mean interaction rate per year: female-female = 62 vs. male-male = 14; P < 0.001), and male-male interactions were 1.5 times longer in duration than female-female interactions (mean interaction length: female-female = 30 s vs. male- male = 45 s; P < 0.001). We propose that fine-scale interactions among members of a population can be modeled as a trade-off between the frequency (quantity) and the duration (quality) of interactions. Our results have implications for understanding sex- based differences in sociality in gregarious herbivores and for disease transmission, which may follow from social intercourse. Key words: behaviour, Cervus canadensis, disease, elk, sexual segregation, sociality. Il est etabli que la structure dans la socialite est associee a des facteurs intrinseques et extrinseques. La mecanique de la socialite exprimee par l'entremise de comportements a petite echelle qui maintiennent les hierarchies, modulent la concurrence ou transmettent des pathogenes est toutefois moins bien comprise. Une nouvelle approche de quantification des comportements sociaux a petite echelle consiste a utiliser des colliers de biotelemetrie qui enregistrent la presence d'autres individus situes a proximite. Cette technologie enregistre des donnees en continu quand des colliers se trouvent en dec; a d'une distance donnee les uns des autres, a des heures du jour et dans des habitats ou les approches ethologiques traditionnelles d'echantillonnage des comportements a l'echelle individuelle ne peuvent etre utilisees. Nous avons verifie un ensemble de predictions concernant la frequence et la duree d'interactions a petite echelle ( Mots-cles: comportement, Cervus canadensis, maladie, wapiti, segregation sexuelle, socialite., Introduction Sociality, broadly defined as group living, has implications for several ecological phenomena (Krause and Ruxton 2002; Silk 2007). It may arise as an adaptive response to a number of [...]

We studied the genetic (microsatellite) diversity of a feral population of horses (Equus caballus L., 1758) on Sable Island, Nova Scotia, Canada (1983-2003), at two spatial scales: (1) for the island as a whole and (2) at the level of four equally sized subdivisions along the length of Sable Island, which is a long (42 km) and narrow (1.5 km) vegetated sand bar. At the island scale (n = 264 horses), observed heterozygosity over 10 loci was 0.647 ± 0.035 (mean ± 1 SE), while expected heterozygosity was 0.696 ± 0.029; we observed significant heterozygote deficiency with all loci considered (P < 0.0001). At the subdivision scale, observed heterozygosity ranged from 0.589 to 0.694 in a gradient from west to east. We observed a corresponding gradient in effective number of alleles and allelic richness. Pairwise values of [F.sub.ST] were significant for most subdivision pairs, ranging as high as 0.067 from west to east. Western areas showed highest levels of inbreeding ([F.sub.IS] = 0.113) with outbreeding indicated in the east ([F.sub.IS] = -0.008). Our results suggest that for a large mammal that lives in polygynous social groups, like the feral horse, gene flow along linear habitats (corridors) may be restricted (relative to the dispersal capabilities of the species), even over short distances. Nous avons etudie la diversite genetique (des microsatellites) dans une population de chevaux (Equus caballus L., 1758) sur l'ile de Sable, Nouvelle-Ecosse, Canada (1983-2003), a deux echelles spatiales, soit (1) de l'ile dans son ensemble et (2) de quatre subdivisions de meme taille le long de l'ile de Sable qui est une longue (42 km) et etroite (1,5 km) barre de sable couverte de vegetation. A l'echelle de l'ile (n = 264 chevaux), l'heterozygotie observee dans 10 locus est de 0,647 ± 0,035 (moyenne ± 1 ecart type) alors que l'heterozygotie attendue est de 0,696 ± 0,029; il y a une carence significative d'heterozygotes lorsqu'on tient compte de tous les locus (P < 0,0001). Au niveau des subdivisions, l'heterozygotie observee varie de 0,589 a 0,694 selon un gradient d'ouest en est. Nous observons un gradient correspondant du nombre effectif d'alleles et de la richesse allelique. Les mesures appariees de [F.sub.ST] sont significatives pour la plupart des paires de subdivisions d'ouest en est, atteignant des valeurs aussi elevees que 0,067. Les regions de l'ouest possedent les niveaux les plus eleves de consanguinite ([F.sub.IS] = 0,113) et il y a des indications d'exogamie dans l'est ([F.sub.IS] = -0,008). Nos resultats laissent croire que chez de grands mammiferes qui vivent en groupes sociaux polygynes, comme le font les chevaux sauvages, le flux genique le long d'habitats lineaires (corridors) peut etre restreint (relativement aux capacites de dispersion de l'espece), meme sur de courtes distances. [Traduit par la Redaction], Introduction Erosion of genetic variation in populations with little or no migration is expected to arise primarily from genetic drift and inbreeding (Falconer and Mackay 1996; Frankham 1998; Frankham et [...]

The relationship between individual performance and nonrandom use of habitat is fundamental to ecology; however, empirical tests of this relationship remain limited, especially for higher orders of selection like that of the home range. We quantified the association between lifetime reproductive success (LRS) and variables describing lifetime home ranges during the period of maternal care (spring to autumn) for 77 female roe deer (Capreolus capreolus) at Trois-Fontaines, Champagne-Ardenne, France (1976-2000). We maintained population growth rate (adjusted to account for removals of non-focal animals) near [r.sub.max], which enabled us to define the fitness habitat relationship in the absence of density effects. Using a negative binomial model, we showed that a roe deer's incorporation into its home range of habitat components important to food, cover, and edge (meadows, thickets, and increased density of road allowances) was significantly related to LRS. Further, LRS decreased with increasing age of naturally reclaimed meadows at the time of a deer's birth, which may have reflected a cohort effect related to, but not entirely explained by, a decline in quality of meadows through time. Predictive capacity of the selected model, estimated as the median Correlation ([r.sub.s]) between predicted and observed LRS among deer of cross-validation samples, was 0.55. The strength of this relationship suggests that processes like selection of the site of a home range during dispersal may play a more important role in determining fitness of individuals than previously thought. Individual fitness of highly sedentary income breeders with high reproductive output such as roe deer should be more dependent on home range quality during the period of maternal care compared to capital breeders with low reproductive output. Identification of the most important habitat attributes to survival and reproduction at low density (low levels of intraspecific competition) may prove useful for defining habitat value ('intrinsic habitat value'). Key words: Capreolus capreolus; fitness; habitat; home range; life history; lifetime reproductive success (LRS); resource selection function; roe deer; Trois-Fontaines, France.

Life-history theory allows predictions of how changes in environmental selection pressures along a species’ geographic distribution result in discrete shifts in life-history traits. We tested for spatial patterns of 24 populations of brown bears Ursus arctos across North America that grouped according to the following environmental and population parameters: evapotranspiration as a correlate of primary productivity of vegetation, coefficient of variation of monthly evapotranspiration values as a measure of seasonality, population density, and adult female weight. Cluster analysis grouped brown bear populations into two regions: Pacific-coastal populations characterized by high population density and large females that lived in areas of high primary productivity and low seasonality, and inland and barren-ground populations characterized by relatively low density and small bears that lived in areas of low productivity and high seasonality. For each region, we tested whether life-history traits (age at maturity and interbirth interval) related to primary productivity or seasonality. High altitude (interior; >1000 m) and high latitude (barren-ground; >65 °N) populations respond to extremes in seasonality with risk-spreading adaptations. For example, age at maturity and interbirth interval increased with greater seasonality. In contrast, Pacific-coastal populations living on the western edge of brown bear geographic range respond to intraspecific competition at high densities by maximizing offspring competitive ability. For example, age at maturity increased with greater primary productivity and high population density. In each region, the female parent decided on the life-history trade-offs required to reduce the risks of offspring mortality depending on the environmental pattern. [ABSTRACT FROM AUTHOR]