Credit to Jeremy Cohen, Osprey

Improving species recovery and reintroductions

The rate of species extinctions and declines continues to rise at an alarming rate. Reversing these dire trends with limited conservation funds requires management efforts that lead to effective and long-lasting population recoveries.

In collaboration with U.S. Geographical Survey and the National Park Service, we used an Integrated Population Model to demonstrate that managing individual nests, scales-up to faster population recovery of bald eagles (Cruz et al. 2018, J. Applied Ecol.). We also evaluated top-down (i.e., recovering bald eagles) and bottom-up factors (i.e., food, weather and nesting habitat) influencing the joint recovery of osprey and great blue herons over 26 years in Minnesota (Cruz et al. 2019, J. Animal Ecol.). The recovery of bald eagles hindered the recovery of ospreys and herons. Achieving ecosystem benefits of returning top predators thus requires multi-species management. 

Bottom-up benefits of habitat restoration

Habitat loss and modification remain key drivers of species declines worldwide. Restoration aims to reverse these trends with the assumption that if habitat is restored, animals will return; but this is seldom assessed. The lab is currently evaluating how long-term changes in habitat influence prey demography (black-tailed jackrabbits and Piute ground squirrels) and predator behavior (Prairie Falcon) at the Morley Nelson Snake River Birds of Prey National Conservation Area. 

To tackle this challenge we are also validating novel techniques for surveying small mammals at a landscape scale. This project is supported by Epscor GEM3, in collaboration with USGS, FWS and the Idaho National Guard. 

Interactions among raptor species

Great Horned Owls are the most common and widespread owl species in North America. They are also dominant competitors and intra-guild predators of other raptors. The lab is quantifying how habitat mediate interactions between Great Horned Owls and subordinate species including Mexican Spotted Owls (in the Grand Canyon National Park) and Aplomado Falcons (in Texas). These projects are in collaboration with the National Park Service and The Peregrine Fund.   

Mexican Spotted Owls

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Evaluating ecological trade-offs of small mammals in semi-arid ecosystems under climate change

Animals survive by minimizing risk and acquiring resources. These ecological trade-offs are amplified in desert habitats, where conditions are becoming more extreme in the Anthropocene. The lab is evaluating how black-tailed jackrabbits in the Sagebrush Steppe ecosystem modify their habitat use to minimize heat stress and acquire food. This will allow us to determine which habitats will become increasingly important to small mammals with a changing climate.

Black-tailed jackrabbit