Coyote Inventory at Cape Hatteras and Cape Lookout National Seashores and Pea Island National Wildlife Refuge

Sossover, Daniel; Kierepka, Elizabeth; Kays, Roland

Over the past two decades, coyotes colonized North Carolina’s barrier-island chain where they have been documented depredating protected shore-nesting birds and sea turtles. Following their arrival, federal agencies have trapped and removed > 170 coyotes, yet the species persists. We combined non-invasive genetic mark-recapture with GPS tracking to describe coyote population and behavior within Cape Hatteras and Cape Lookout National Seashores and Pea Island National Wildlife Refuge. We implemented a multistate robust design model to provide estimates of island-specific abundance, apparent survival, inter-island movement, and detection probability. Average site densities ranged from 0.05 to 0.86 coyotes/km², with Bodie having the highest average density, followed by Pea Island, Shackleford Banks, South Core Banks, Hatteras, Ocracoke, and North Core. We used tracking data to quantify space use, characterize inter-island movement, and evaluate the efficacy of fladry, a non-lethal deterrent, at reducing entry in sensitive nesting areas. While most monitored coyotes remained on the island where they were first detected, we documented inter-island movement with both datasets: genetic recaptures revealed a resident female moving from North Core Banks to Ocracoke and back (~4 km), and another female on Cape Lookout made >50 crossings among Shackleford Banks, Morgan Island, and South Core Banks, predominately at night and often near low tide. While these events are uncommon, they demonstrate functional connectivity which appears to be at a level sufficient to refill vacancies caused by lethal removal. Additionally, pack sizes on Hatteras and Bodie remained stable across seasons despite over a dozen animal removals. Furthermore, we did not find clear population reduction in our population due to removal. Our model showed that apparent survival tended to be lower where predator management occurred, but the effect size was small and highly uncertain with credible intervals overlapping zero, and abundance did not consistently decline following culling events. The fladry experiment coincided with an overall reduction in boundary crossings at the group level (~66% reduction) demonstrating its ability to reduce incursions into sensitive nesting areas. Overall, our results demonstrate that sustained suppression or eradication of coyote populations on the Outer Banks is unlikely, and that management aimed at modifying their behavior has a greater potential to reduce their impacts on vulnerable nesting species.

Coyote Inventory at Cape Hatteras and Cape Lookout National Seashores and Pea Island National Wildlife Refuge

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