Filters: Tags: resource partitioning (X)2 results (53ms)
Coyotes and recolonizing wolves: social rank mediates risk-conditional behaviour at ungulate carcasses
Wolf, Canis lupus, recolonization of the Greater Yellowstone Ecosystem provides a rare opportunity to identify behaviours facilitating coexistence between sympatric canids. We investigated interactions between coyotes, Canis latrans, and recolonizing wolves at ungulate carcasses in Montana's Madison Range. We used a field-experimental study design consisting of a two-level carcass treatment (wolf presence, wolf absence) to assess factors influencing coyote risk assessment, carrion consumption and aggressive encounters with wolves. Socially dominant coyotes (alphas and betas) responded to wolf presence by increasing the proportion of time spent vigilant while scavenging. Vigilance behaviour was more pronounced when...
Shifts in depth of water extraction and photosynthetic capacity inferred from stable isotope proxies across an ecotone of Juniperus osteosperma (Utah juniper) and Artemisia tridentata (big sagebrush)
* 1 In western North America, juniper trees (Juniperus spp.) are apparently encroaching into numerous communities including sagebrush-dominated (Artemisia tridentata) valleys, where, as density of juniper increases, the density and condition of sagebrush decline but juniper condition appears unaffected. * 2 We examined stable isotope proxies of plant gas exchange and relative depth of soil water extraction of Juniperus osteosperma and Artemisia tridentata as their relative densities changed across a transition zone in northern Utah, USA. Measurement of 13C and 18O of foliage allowed separation of the contributions of stomatal and biochemical factors to differences in mean intercellular CO2 concentration, while deuterium...