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Interactions Between Apex Predators


Image by Robert Thiemann

Foraging in a Landscape of Risk: The Predatory Behavior of Large Carnivores

The intensifying global extinction crisis is primarily driven by the impact of humans on wildlife populations. Large-bodied mammals are particularly at risk, including large carnivores that often come into conflict with humans, e.g., they kill livestock, game species, and occasionally, human beings. While a wealth of research attempts to understand the indirect effects of risk on prey populations and subsequent ecosystem function, we still have a limited understanding of how human-induced risk effects influence large carnivores. Our objective is to investigate how the predatory behavior of two large felids, snow leopard and lynx, is affected by anthropogenic and natural risk. Specifically, we aim to investigate how felid behavior around their kills, and subsequent access to food biomass, differs with relative risk at kill sites.

Competition Between Apex Predators

After a century or more of decline, wolf and brown bear populations are starting to rebound in some areas of the world and functionally coexist again. Yellowstone National Park and the Scandinavian Peninsula both support recently recovered wolf and brown bear populations. With respect to these two species, these systems are some of the most heavily studied in the world. Yet the majority of the research has generally focused on either wolves or bears, independently of one another. I am currently working with the Norwegian Institute for Nature Research, The Scandinavian Brown Bear Project, the Scandinavian Wolf Project, and Yellowstone National Park to understand how these two species affect each other.

Photo Credit: Dan Stahler - Yellowstone National Park

Foraging Ecology

Animals eat. This is a fundamental fact of life. But determining the extrinsic factors that affect what, when, where, and how they eat is less straightforward. My research focuses on how dangerous prey species alter predator hunting behavior and change predicted predation patterns. However, few studies have measured the behavioral relationships between predators and their most formidable and dangerous prey species. Understanding how predators modify their foraging behavior to cope with dangerous prey species is important for understanding the dynamics of natural systems. Wolf-bison interactions represent an ideal case study to understand relationships between predators and dangerous prey in carnivore-ungulate systems, which are classic model systems for studying predator-prey interactions. 

Photo Credit: Dan Stahler - Yellowstone National Park

Predator Reintroduction

Wolves were reintroduced to Yellowstone National Park in 1996-1997, and park researchers and managers are still trying to understand how their presence impacts the ecosystem. My research contributes to the current body of work addressing the effects of wolf-reintroduction in Yellowstone, and is unique because it focuses on wolf-bison interactions, which are a little-studied aspect of this system. Wolf-bison systems were almost completely wiped out during the turn of the 19th century, and the recovery and conservation of both species is an on-going objective of both government agencies and non-government organizations. Understanding the life-history traits that allow wolves to successfully hunt bison, the ability of wolves to incorporate bison into their diet, the spatial response of bison to wolf predation provides new insight into how wolf-bison systems function, and can help guide restoration and recovery efforts.


Photo Credit: Dan Stahler - Yellowstone National Park


Documentary: The Legacy Effects of Megaherbivores

The Legacy of Megaherbivores will ‘follow’ the life and death of an elephant in the African savanna, explaining their effect on ecosystem function in both life and death. The life cycle of these megaherbivores will be put into broader ecological context, showing how megaherbivores impact ecosystems and the current implications for ecosystems facing their disappearance. This documentary is part of the Broader Impacts program for an NSF funded grant, the Ecological legacy effects of megacarcasses in African savanna ecosystems.

Image by Nam Anh

Wolves Across Borders

Wolves Across Borders is an international conference on wolf ecology and management to be held in Stockholm, Sweden in May 2022. Wolves Across Borders is hosted by the Scandinavian Wolf Research Group and funded by the EPA's of Sweden, Norway, and Finland, WWF Sweden, and Interreg Sweden-Norway.

Science Education Nonprofit

Our World of Wildlife is a science outreach program that works with biologists to translate, communicate, and disseminate high-level scientific research, teach basic ecology and biology concepts, and engage young people in science. Our mission is to facilitate nature conservation efforts through science education and communication.

Children's Book Series

Sophie the Sea Otter, tells the story of Sophie, an otter who lives happily in a kelp forest in the ocean. When she and her friends are driven out of their home, however, their absence has disastrous results for the kelp forests that provide food and shelter for so many other species.


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