Animals within social groups respond to costs and benefits of sociality by adjusting the proportion of time they spend in close proximity to other individuals in the group (cohesion). Variation in cohesion between individuals, in turn, shapes important group-level processes such as subgroup formation and fission-fusion dynamics. Although critical to animal sociality, a comprehensive understanding of the factors influencing cohesion remains a gap in our knowledge of cooperative behavior in animals.
View Article and Find Full Text PDFIn many southern boreal ecosystems of North America, wolves are the primary predators of white-tailed deer, and white-tailed deer are the primary prey of wolves. Furthermore, wolf-deer systems have and will continue to become more common as white-tailed deer range continues expanding northward in North America. Despite this, there is little information on kill rates of wolves on deer (i.
View Article and Find Full Text PDFRecolonization of predators to their former ranges is becoming increasingly prevalent. Such recolonization places predators among their prey once again; the latter having lived without predation (from such predators) for a considerable time. This renewed coexistence creates opportunities to explore predation ecology at both fundamental and applied levels.
View Article and Find Full Text PDFPredators can directly and indirectly alter the foraging behaviour of prey through direct predation and the risk of predation, and in doing so, initiate indirect effects that influence myriad species and ecological processes. We describe how wolves indirectly alter the trajectory of forests by constraining the distance that beavers, a central place forager and prolific ecosystem engineer, forage from water. Specifically, we demonstrate that wolves wait in ambush and kill beavers on longer feeding trails than would be expected based on the spatio-temporal availability of beavers.
View Article and Find Full Text PDFThe demands of raising dependent young can influence the feeding behaviors of social carnivores, especially for individuals that are primarily responsible for provisioning young. We investigated how the feeding and provisioning behavior of a social carnivore, gray wolves (Canis lupus), are connected and shaped by extrinsic and intrinsic factors, and whether and how these patterns changed throughout the pup-rearing season (April-August). We found breeding wolves had shorter handling times of prey, lower probability of returning to kills, and greater probability of returning to homesites after kills compared to subordinate individuals.
View Article and Find Full Text PDFHumans are increasingly recognized as important players in predator-prey dynamics by modifying landscapes. This trend has been well-documented for large mammal communities in North American boreal forests: logging creates early seral forests that benefit ungulates such as white-tailed deer (Odocoileus virginianus), while the combination of infrastructure development and resource extraction practices generate linear features that allow predators such as wolves (Canis lupus) to travel and forage more efficiently throughout the landscape. Disturbances from recreational activities and residential development are other major sources of human activity in boreal ecosystems that may further alter wolf-ungulate dynamics.
View Article and Find Full Text PDFThrough global positioning system (GPS) collar locations, remote cameras, field observations and the first wild wolf to be GPS-collared with a camera collar, we describe when, where and how wolves fish in a freshwater ecosystem. From 2017 to 2021, we recorded more than 10 wolves () hunting fish during the spring spawning season in northern Minnesota, USA. Wolves ambushed fish in creeks at night when spawning fish were abundant, available and vulnerable in shallow waters.
View Article and Find Full Text PDFRail and road infrastructure is essential for economic growth and development but can cause a gradual loss in biodiversity and degradation of ecosystem function and services. We assessed the influence of underpass dimensions, fencing, proximity to water and roads, Normalized Difference Vegetation Index (NDVI), presence of other species and livestock on underpass use by large and medium-sized mammals. Results revealed hyenas and leopards used the underpasses more than expected whereas giraffes and antelopes used the underpasses less than expected.
View Article and Find Full Text PDFUnderstanding sexual segregation is crucial to comprehend sociality. A comparative analysis of long-term lion data from Serengeti and Ngorongoro in Tanzania, and Gir in India, reveals that male-female associations are contingent upon male and female group size, prey-size and availability, and the number of prides that each male coalition currently resides. Males maintain proximity with females, whereas females are responsible for segregation except at large kills.
View Article and Find Full Text PDFRoadkill is one of the highest causes of wildlife mortality and is of global conservation concern. Most roadkill studies have focused on wildlife in developed countries such as the United States of America and temperate biomes, but there are limited data for the impacts of roads on wildlife in the African tropics, where road infrastructure development is projected to grow rapidly in natural environments and conservation areas. The Tsavo Conservation Area is an important biodiversity hotspot in eastern Kenya and is bisected by a major highway and railways that connect the port of Mombasa to the interior.
View Article and Find Full Text PDFGray wolves are a premier example of how predators can transform ecosystems through trophic cascades. However, whether wolves change ecosystems as drastically as previously suggested has been increasingly questioned. We demonstrate how wolves alter wetland creation and recolonization by killing dispersing beavers.
View Article and Find Full Text PDFThe influence of kinship on animal cooperation is often unclear. Cooperating Asiatic lion coalitions are linearly hierarchical; male partners appropriate resources disproportionately. To investigate how kinship affect coalitionary dynamics, we combined microsatellite based genetic inferences with long-term genealogical records to measure relatedness between coalition partners of free-ranging lions in Gir, India.
View Article and Find Full Text PDFAccording to the ideal-free distribution (IFD), individuals within a population are free to select habitats that maximize their chances of success. Assuming knowledge of habitat quality, the IFD predicts that average fitness will be approximately equal among individuals and between habitats, while density varies, implying that habitat selection will be density dependent. Populations are often assumed to follow an IFD, although this assumption is rarely tested with empirical data, and may be incorrect when territoriality indicates habitat selection tactics that deviate from the IFD (e.
View Article and Find Full Text PDFStudies that assess mercury bioaccumulation in small carnivores in terrestrial habitats are limited. We quantified total mercury (THg) in American marten () that were harvested for fur in Michigan, US, during 2013 and 2014. We quantified THg (dry weight) in hair, kidney, and liver samples and further analyzed hair for potential demographic and ecological factors that influence THg bioaccumulation.
View Article and Find Full Text PDFHabitat selection is a process that spans space, time and individual life histories. Ecological analyses of animal distributions and preferences are most accurate when they account for inherent dynamics of the habitat selection process. Strong territoriality can constrain perception of habitat availability by individual animals or groups attempting to colonize or establish new territory.
View Article and Find Full Text PDFEstimation of population trends and demographic parameters is important to our understanding of fundamental ecology and species management, yet these data are often difficult to obtain without the use of data from population surveys or marking animals. The northeastern Minnesota moose ( Linnaeus, 1758) population declined 58% during 2006-2017, yet aerial surveys indicated stability during 2012-2017. In response to the decline, the Minnesota Department of Natural Resources (MNDNR) initiated studies of adult and calf survival to better understand cause-specific mortality, calf recruitment, and factors influencing the population trajectory.
View Article and Find Full Text PDFThe decomposition of animal biomass (carrion) contributes to the recycling of energy and nutrients through ecosystems. Whereas the role of plant decomposition in ecosystems is broadly recognised, the significance of carrion to ecosystem functioning remains poorly understood. Quantitative data on carrion biomass are lacking and there is no clear pathway towards improved knowledge in this area.
View Article and Find Full Text PDFPhysiological stress in wildlife can be a useful indicator of a population's response to environmental factors. By using non-invasive endocrinological techniques, such as fecal sampling, potential confounding factors associated with the stress of capture can be avoided. A potential drawback of fecal sampling, however, is degradation of samples which may produce aberrant measurements of fecal glucocorticoid metabolites.
View Article and Find Full Text PDFPhilos Trans R Soc Lond B Biol Sci
October 2018
Trophic rewilding maintains that large mammals are functionally important to resource subsidies and nutrient repletion, yet this prediction is understudied. Here, I report on the potential magnitude and variability of nitrogen that moose populations move from aquatic to terrestrial ecosystems. My aim is to provide justified approximations of the role of moose in the flux of a limiting nutrient across ecotones and to illustrate how this role is linked to wolf predation and climate warming.
View Article and Find Full Text PDFLocating wolf () homesites is valuable for understanding the foraging behavior, population dynamics, and reproductive ecology of wolves during summer. During this period wolf pack members (adults and pups) readily respond to simulated wolf howls (i.e.
View Article and Find Full Text PDFUnderstanding landscape patterns in mortality risk is crucial for promoting recovery of threatened and endangered species. Humans affect mortality risk in large carnivores such as wolves (), but spatiotemporally varying density dependence can significantly influence the landscape of survival. This potentially occurs when density varies spatially and risk is unevenly distributed.
View Article and Find Full Text PDFBackground: Recent findings indicate that cougars (Puma concolor) are expanding their range into the midwestern United States. Confirmed reports of cougar in Michigan, Minnesota, and Wisconsin have increased dramatically in frequency during the last five years, leading to speculation that cougars may re-establish in the Upper Great Lakes (UGL) region, USA. Recent work showed favorable cougar habitat in northeastern Minnesota, suggesting that the northern forested regions of Michigan and Wisconsin may have similar potential.
View Article and Find Full Text PDF