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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 km² ) 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. [ABSTRACT FROM AUTHOR]

For species living in seasonal environments the understanding of demographic processes requires identifying the environmental factors during spring and summer that shape phenotypic variation. We assessed the effects of plant phenology and population abundance during spring-summer on variation in autumn body mass among cohorts (1995-2006) of juvenile alpine chamois (Rupicapra rupicapra). We computed several metrics based on the normalized difference vegetation index (NDVI) to assess interannual variation in plant phenology and productivity. Body mass of both sexes decreased similarly during years with late springs (-20%) and with increasing population abundance (-15%), with no interactive effect. Our results also suggested that forage quality more than forage quantity influenced body mass of juveniles. Variation in body mass of juveniles thus can be used as an indicator of the relationship between chamois populations and their environment. This study also demonstrates the utility of satellite-based data in increasing our understanding of the consequences of spring-summer conditions on life-history traits. [ABSTRACT FROM AUTHOR]

Predation risk from lions (Panthera leo) has been linked to habitat characteristics and availability and traits of prey. We separated the effects of vegetation density and the presence of drinking water by analyzing locations of lion kills in relation to rivers with dense vegetation, which offer good lion stalking opportunities, and artificial water points with low vegetation density. The spatial distribution of lion kills was studied at the Klaserie Private Nature Reserve, South Africa. The distance between 215 lion kills and the nearest water source was analyzed using generalized linear models. Lions selected medium-sized prey species. Lion kills were closer to rivers and to artificial water points than expected by random distribution of the kills. Water that attracted prey, and not the vegetation density in riverine areas, increased predation risk, with kills of buffalo (Syncerus caffer), kudu (Tragelaphus strepsiceros), and wildebeest (Connochaetes taurinus) as water-dependent prey species. Traits of prey species, including feeding type (food habits), digestion type (ruminant or nonruminant), or body size, did not explain locations of lion kills, and no seasonal patterns in lion kills were apparent. We argue that the cascading impact of lions on local mammal assemblages is spatially heterogeneous. [ABSTRACT FROM AUTHOR]

The golden takin (Budorcas taxicolor bedfordi) is a large, forest-dwelling ungulate endemic to the Qinling Mountains, China. A recent study showed that golden takin move to different elevations depending on the season, remaining at high elevations in summer, intermediate elevations in winter, and at low elevations for short periods in spring and autumn. We proposed the following hypotheses: seasonal movement of golden takin is a response to a shift in vegetation phenology, which affects forage quality; and uphill movement of golden takin in winter is an adaptation to select areas with higher thermal energy. To test the 1st hypothesis we used relative phenological development derived from the normalized difference vegetation index time series to link seasonal shifts in vegetation phenology to movement patterns of golden takin. Golden takin descended to a low elevation with the greening of vegetation in early spring, ascended to a high elevation in late spring, and descended again in autumn as vegetation senesced. To test the 2nd hypothesis we compared thermal energy in the winter habitat with that in other areas of the home range, using the amount of solar radiation calculated by a solar radiation model. In winter, preference of the golden takin for exposed southern slopes at intermediate elevations correlated closely with areas of higher solar radiation. Our results indicate that solar radiation and vegetation phenology are critical factors in driving seasonal movement of golden takin. [ABSTRACT FROM AUTHOR]

Individual differences in body mass exert a major influence on several life-history traits of mammals. We investigated the factors influencing variation in body mass of calves of migratory caribou (Rangifer tarandus) at birth (June, 19 years of data) and in autumn (October, 15 years of data) in the Rivière-aux-Feuilles (Feuilles, 1991-2003) herd and the Rivière-George (George, 1978-2003) herd in Québec and Labrador, Canada. Mass at birth (hereafter, birth mass) did not differ between herds, possibly because part of their winter ranges overlapped. However, Feuilles calves were smaller in autumn than George calves, possibly reflecting differences in summer ranges. The birth mass of calves also varied with year, likely as the outcome of both intrinsic and extrinsic factors. Birth and autumn body mass were influenced positively by habitat quality in June, estimated by the normalized difference vegetation index. The North Atlantic Oscillation of the previous winter was positively correlated with autumn mass of the George calves. Previous winter snowfall was negatively related to the mass of George calves, and daily movement rates in summer were negatively correlated with the mass of calves of both herds in autumn. Birth mass was positively related with productivity in October in the George herd and also with productivity 3 and 4 years later, which corresponds to the beginning of reproduction of females. We suggest that a mechanism of delayed quality effect of the calves could have been involved in the decrease of fall productivity and population size of the George herd. [ABSTRACT FROM AUTHOR]