Research

My research broadly focuses on spatial demography of wild populations. Specifically, I investigate factors influencing spatial and temporal variation in demographic rates, habitat use, and species distributions to better understand wildlife-habitat relationships and improve conservation and monitoring programs. While diverse in taxa, my research unifies complementary topics in population ecology, movement ecology, and landscape ecology through integrated modeling approaches that link field data to population processes in terrestrial and aquatic ecosystems.

Some examples of my recent projects are provided below.

JOINTLY ESTIMATING ABUNDANCE, DEMOGRAPHIC RATES, AND MOVEMENT

Objectives: Understand spatio-temporal variation in polar bear abundance, movement, and demographic rates through the development of field protocols and integrated modelling approaches linking mark-recapture, telemetry, count, and age data.

Collaborators:  University of Washington, U.S. Geological Survey – Washington Cooperative Fish and Wildlife Research Unit, U.S. Geological Survey – Patuxent Wildlife Research Center, U.S. Fish and Wildlife Service, Environment and Climate Change Canada, Polar Science Center – University of Washington

Funding: North Pacific Research Board, U.S. Geological Survey, U.S. Fish and Wildlife

Publications: Integrated population modeling provides the first empirical estimates of vital rates and abundance for polar bears in the Chukchi Sea (here) and more to come from this on-going project.

SPATIOTEMPORAL OCCUPANCY DYNAMICS AT A SPECIES RANGE BOUNDARY

Objectives: Develop a large-scale monitoring protocol and dynamic occupancy modeling framework to track spatiotemporal Canada lynx occurrence, link occupancy dynamics to habitat covariates, and identify multi-year core use areas at the southern periphery of the species range.

Collaborators: Superior National Forest, U.S. Fish and Wildlife Service, University of Washington

Funding: U.S. Fish and Wildlife

Publications: Quantifying spatiotemporal occupancy dynamics and multi-year core use areas at a species range boundary (In-review).

MIGRATION DYNAMICS AND SPATIOTEMPORAL ABUNDANCES

Objectives: Integrate count and mark-resight data to jointly estimate abundance and migration dynamics. We apply these methods to estimate Atlantic sturgeon spawning abundances, the cumulative number of individuals that used the spawning area (i.e. superpopulation), and variation in individual-level arrival and departure timing in the Hudson River, New York.

Collaborators:  Cornell, Delaware State University, University of Delaware, University of Washington – Washington Cooperative Fish and Wildlife Research Unit, U.S. Geological Survey

Funding: National Marine Fisheries Service, the Hudson River Foundation Bain Fellowship Program, DuPont Clear into the Future Program

Publications: Integrating side-scan sonar and acoustic telemetry to estimate the annual spawning run size of Atlantic sturgeon in the Hudson River (here).

QUANTIFYING THE IMPACT OF PREDATION ON PREY POPULATIONS IN COMPLEX MULTI-PREDATOR SYSTEMS

Objectives: Multi-year study investigating Endangered Species Act listed salmonid survival, predator-prey dynamics, and the impacts of colonial waterbird predation on population recovery.

Collaborators:  Oregon State University, Real Time Research Inc., University of Washington, U.S. Geological Survey – Oregon Cooperative Fish and Wildlife Research Unit

Funding: Bonneville Power Administration, Grant County Public Utility District, Oregon Department of Fish and Wildlife, U.S. Army Corps of Engineers

Publications: (10+ peer-reviewed publications) Cumulative Effects of Avian Predation on Upper Columbia River Steelhead (here), Wanted dead or alive: a state-space mark–recapture–recovery model incorporating multiple recovery types and state uncertainty (here), see Publications section for growing list of publications from this work.

ABUNDANCE AND THE COMPONENTS OF DETECTION PROBABILITY IN UNMARKED POPULATIONS

Objectives: We develop a framework to estimate abundance in unmarked populations by integrating common survey methods including spatially and temporally replicated counts, distance sampling, and time-of-detection data. Application of these approaches are used to estimate Island Scrub-Jay abundance for the available, present, and superpopulation of individuals, and tease apart the detection processes for presence during a survey, availability given presence, and detection given availability and presence.

Collaborators:  Migratory Bird Center – Smithsonian Conservation Biology Institute, North Carolina State University, University of Washington

Funding: The Nature Conservancy, University of California’s Santa Cruz Island Reserve, North Carolina State University

Publications: An integrated model decomposing the components of detection probability and abundance in unmarked populations (here).

OPTIMIZING RELEASE STRATEGIES FOR SPECIES REINTRODUCTIONS

Objectives: Evaluation of alternative management strategies enables informed decisions to accelerate species recovery. Here, we develop a novel multievent modelling framework integrating encounter history and biotelemetry data to evaluate the success of reintroduction strategies for the critically endangered Vancouver Island marmot. Results from this work provide a generalizable framework to evaluate species reintroduction programs and have directly informed the management of Vancouver Island marmots.

Collaborators:  Calgary Zoo, Marmot Recovery Foundation, University of Washington, U.S. Geological Survey – Washington Cooperative Fish and Wildlife Research Unit

Funding: Fish and Wildlife Compensation Program, Ministry of Forests, Lands and Natural Resource Operations

Publications: Optimizing release strategies: a stepping‐stone approach to reintroduction (here). Future directions to escalate benefits of the stepping-stone approach for conservation translocations (here).