Hyena-Tiger-Leopard-Jackal Competition

Our new paper on competition among large carnivores in India has been published: https://link.springer.com/article/10.1007/s13364-022-00663-1

We studied how striped hyenas compete with tigers, leopards, and golden jackals for carrion in Rajasthan, India, using camera traps. We found that tigers dominated carcasses, greatly limiting the feeding opportunities of hyenas and other scavengers. Leopards and hyenas coexisted with little conflict, but jackals and hyenas strongly reduced each other’s feeding efficiency. Our results show how traits like body size and social foraging shape competition at carcasses and directly affect the energy animals gain from scavenging.

Using video camera collars to understand bear diet

Our new article explores using video cameras in bear collars to understand nuances of their diet: https://academic.oup.com/jmammal/article/104/1/184/6847075

We used video cameras mounted on collars we placed on Asian black bears to compare video footage of their foraging with traditional fecal analysis. We found that video provided unique insights—such as detecting leaves or mammal prey that are hard to identify in feces—while fecal analysis still captured items that were quickly or rarely eaten. Together, these methods give a more complete picture of bear diets, showing that video collars are a valuable new tool for studying individual differences in feeding behavior.

Carnivore Community in the Apostle Islands

Our new research paper studying the carnivore community in the Apostle Islands has been published. The distribution and occupancy of carnivores in the Apostle Islands is largely unknown. We monitored 19 islands with 160 functioning camera traps from 2014-2017, from which we collected 203,385 photographs across 49,280 trap nights.

We documented detected 10 of the 12 terrestrial carnivores found in Wisconsin. Detection rates for species were generally higher in summer than winter. We estimated that terrestrial carnivore species varied in the number of islands they were detected on from 1 island for gray wolves to 13 islands for black bears. The number of carnivores occupying an island also varied substantively from 1 species on Michigan Island to 10 species on Stockton Island. Island size and connectivity between islands appear important for the persistence of the carnivore community in the Apostle Islands

State Space Model for Black Bear Populations

Our new paper describing our population model for black bears in Wisconsin has been published in Scientific Reports.

Population estimation is essential for the conservation and management of fish and wildlife, but accurate estimates are often difficult or expensive to obtain for cryptic species across large areas. We developed a two-stage state-space Bayesian model for black bears with age-at-harvest data, but little demographic data and no auxiliary data available. We created a statewide population estimate and tested the sensitivity of the model to bias in the prior distributions of parameters and initial population size.

The posterior abundance estimate from our model was similar to an independent capture-recapture estimate from tetracycline sampling and the population trend was similar to the catch-per-unit-effort for the state. Our model was also robust to bias in the prior distributions for all parameters, including initial population size, except for reporting rate. Our state-space model improves on previous models by using little demographic data, no auxiliary data, and not being sensitive to initial population size.

New Paper in Ecology

We published a manuscript in Ecology. The manuscript focuses on determining the traits and other values that determine who wins during competition between mesocarnivores. Encounter competition theory has never been tested with carnviores, and so I created foraging arenas and recorded fights between mesocarnivores over food. Surprisingly, bobcats and spotted skunks won more encounters than expected, while canines lost more often than expected. I think bobcats and skunks were able to win because of their unique weapons.