Vulture Exclusion Halves Large Carcass Decomposition Rates and Doubles Fly Abundance.

Carcass consumption by scavengers plays a critical role in wildlife and human health by providing services that maintain ecosystem functioning and potentially mitigate disease spreading. Vultures are particularly efficient scavengers, but their populations have sharply declined in Europe, Asia and Africa, raising concerns about similar declines in the comparatively less studied species of the Americas. While the effects of vulture absence on other vertebrate scavengers have been examined, the impact on invertebrate scavengers and their role in carrion decomposition remains unexplored.

Determination of hematologic reference intervals for free-living King vultures (Sarcoramphus papa).

Background: As obligate scavengers, New World vultures (Cathartiformes: Cathartidae) play a key role in carcass removal and disease control. Associated with this ecosystem service, vultures are exposed to the consumption of harmful substances such as poisons, heavy metals, antibiotics, or non-steroidal anti-inflammatory drugs. Monitoring the health status of vulture populations is a priority and an important conservation strategy, and hematologic analysis is a practical and effective method that can be useful for this purpose.

Disturbance-mediated changes to boreal mammal spatial networks in industrializing landscapes.

Compound effects of anthropogenic disturbances on wildlife emerge through a complex network of direct responses and species interactions. Land-use changes driven by energy and forestry industries are known to disrupt predator-prey dynamics in boreal ecosystems, yet how these disturbance effects propagate across mammal communities remains uncertain. Using structural equation modeling, we tested disturbance-mediated pathways governing the spatial structure of multipredator multiprey boreal mammal networks across a landscape-scale disturbance gradient within Canada's Athabasca oil sands region.

Mapping climate adaptation corridors for biodiversity-A regional-scale case study in Central America.

Climate adaptation corridors are widely recognized as important for promoting biodiversity resilience under climate change. Central America is part of the Mesoamerican biodiversity hotspot, but there have been no regional-scale analyses of potential climate adaptation corridors in Central America. We identified 2375 potential corridors throughout Central America that link lowland protected areas (≤ 500 m) with intact, high-elevation forests (≥ 1500 m) that represent potential climate change refugia.

Mammal responses to global changes in human activity vary by trophic group and landscape.

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely.

Mammalian predator and prey responses to recreation and land use across multiple scales provide limited support for the human shield hypothesis.

Outdoor recreation is widespread, with uncertain effects on wildlife. The human shield hypothesis (HSH) suggests that recreation could have differential effects on predators and prey, with predator avoidance of humans creating a spatial refuge 'shielding' prey from people. The generality of the HSH remains to be tested across larger scales, wherein human shielding may prove generalizable, or diminish with variability in ecological contexts.

Disappearance of an ecosystem engineer, the white-lipped peccary (Tayassu pecari), leads to density compensation and ecological release.

Given the rate of biodiversity loss, there is an urgent need to understand community-level responses to extirpation events, with two prevailing hypotheses. On one hand, the loss of an apex predator leads to an increase in primary prey species, triggering a trophic cascade of other changes within the community, while density compensation and ecological release can occur because of reduced competition for resources and absence of direct aggression. White-lipped peccary (Tayassu pecari-WLP), a species that typically co-occurs with collared peccary (Pecari tajacu), undergo major population crashes-often taking 20 to 30-years for populations to recover.

Behavioral "bycatch" from camera trap surveys yields insights on prey responses to human-mediated predation risk.

Human disturbance directly affects animal populations and communities, but indirect effects of disturbance on species behaviors are less well understood. For instance, disturbance may alter predator activity and cause knock-on effects to predator-sensitive foraging in prey. Camera traps provide an emerging opportunity to investigate such disturbance-mediated impacts to animal behaviors across multiple scales.

Human disturbance and shifts in vertebrate community composition in a biodiversity hotspot.

Understanding how human modification of the landscape shapes vertebrate community composition is vital to understanding the current status and future trajectory of wildlife. Using a participatory approach, we deployed the largest camera-trap network in Mesoamerica to date to investigate how anthropogenic disturbance shapes the occupancy and co-occurrence of terrestrial vertebrate species in a tropical biodiversity hotspot: the Osa Peninsula, Costa Rica. We estimated species richness in different categories of land protection with rarefaction analysis and estimated the expected occupancy with a joint species distribution model that included covariates for anthropogenic disturbance, land protection, habitat quality, and habitat availability.

African forest elephant movements depend on time scale and individual behavior.

The critically endangered African forest elephant (Loxodonta cyclotis) plays a vital role in maintaining the structure and composition of Afrotropical forests, but basic information is lacking regarding the drivers of elephant movement and behavior at landscape scales. We use GPS location data from 96 individuals throughout Gabon to determine how five movement behaviors vary at different scales, how they are influenced by anthropogenic and environmental covariates, and to assess evidence for behavioral syndromes-elephants which share suites of similar movement traits. Elephants show some evidence of behavioral syndromes along an 'idler' to 'explorer' axis-individuals that move more have larger home ranges and engage in more 'exploratory' movements.

Forest elephant movement and habitat use in a tropical forest-grassland mosaic in Gabon.

Poaching of forest elephants (Loxodonta cyclotis) for ivory has decimated their populations in Central Africa. Studying elephant movement can provide insight into habitat and resource use to reveal where, when, and why they move and guide conservation efforts. We fitted 17 forest elephants with global positioning system (GPS) collars in 2015 and 2016 in the tropical forest-grassland mosaic of the Wonga Wongué Presidential Reserve (WW), Gabon.

Age-related declines in immune response in a wild mammal are unrelated to immune cell telomere length.

Senescence has been hypothesized to arise in part from age-related declines in immune performance, but the patterns and drivers of within-individual age-related changes in immunity remain virtually unexplored in natural populations. Here, using a long-term epidemiological study of wild European badgers (Meles meles), we (i) present evidence of a within-individual age-related decline in the response of a key immune-signalling cytokine, interferon-gamma (IFNγ), to ex vivo lymphocyte stimulation, and (ii) investigate three putative drivers of individual variation in the rate of this decline (sex, disease and immune cell telomere length; ICTL). That the within-individual rate of age-related decline markedly exceeded that at the population level suggests that individuals with weaker IFNγ responses are selectively lost from this population.

Sex differences in senescence: the role of intra-sexual competition in early adulthood.

Males and females frequently differ in their rates of ageing, but the origins of these differences are poorly understood. Sex differences in senescence have been hypothesized to arise, because investment in intra-sexual reproductive competition entails costs to somatic maintenance, leaving the sex that experiences stronger reproductive competition showing higher rates of senescence. However, evidence that sex differences in senescence are attributable to downstream effects of the intensity of intra-sexual reproductive competition experienced during the lifetime remains elusive.

Age-related declines and disease-associated variation in immune cell telomere length in a wild mammal.

Immunosenescence, the deterioration of immune system capability with age, may play a key role in mediating age-related declines in whole-organism performance, but the mechanisms that underpin immunosenescence are poorly understood. Biomedical research on humans and laboratory models has documented age and disease related declines in the telomere lengths of leukocytes ('immune cells'), stimulating interest their having a potentially general role in the emergence of immunosenescent phenotypes. However, it is unknown whether such observations generalise to the immune cell populations of wild vertebrates living under ecologically realistic conditions.

Five years' experience of transverse groin incision for femoral artery access in arterial reconstructive surgery: parallel observational longitudinal group comparison study.

Vertical groin incisions (VGIs) have been used to access femoral vessels, but reports allude to wound complications. Our aim was to compare VGI with transverse groin incision (TGI) for femoral artery exposure. Over a 5-year interval, 196 patients with 284 femoral artery exposures for supra- and infrainguinal procedures were studied.