1. Seasonal occupancy patterns of eastern coyotes in urban parks in Bronx, NY
Christopher Nagy, Mianus River Gorge; Bedford, NY
Mark Weckel, American Museum of Natural History; New York, NY
Suzanne Clemente, Pace University; Pleasantville, NY
Introduction - Coyotes (Canis latrans) are common in most of the East Coast, including New York State. More recently, they have begun to colonize the boroughs of New York City (NYC), beginning with large parks in the Bronx.
Since 2012, we have surveyed 10 parks biannually to record site occupancy and breeding status, activity patterns, and the presence of other wildlife.
Here, we examined seasonal changes in occupancy across multiple breeding and non-breeding seasons.
Results –The top models (AICc wi >0.95) for all breeding seasons included constant estimates for all parameters. In two non-breeding seasons, we found a positive relationship between park size and detection rate (mean β = ; SE = ), but no other relationships between size and other parameters.
Occupancy did not change greatly from year to year (Fig 2). However, R increased from 0.39 in 2012 to 0.74 in 2014.
Detection of adults (p1) ranged from 0.57 to 0.87 across seasons while detection of pups (p2) was more variable, ranging from 0.35 to 0.90.
Discussion – Site occupancy was higher in the non-breeding than in the breeding seasons (Fig 2). Coyotes may concentrate their activity near their dens during breeding and roam farther in the non-breeding season. This shift could also reflect dispersal of juveniles in the fall and subsequent mortality or return to natal site by spring.
We identified two “levels” of site occupancy from our observations: 1) parks used only during the non-breeding season and, 2) parks occupied seasonally that then transition to breeding sites within 1 – 2 years. We also observed 1 park go from unoccupied to successful breeding in 2 years. These patterns suggest that, given suitable habitat patches, coyotes can find such patches and begin breeding rapidly even in the most urban landscapes.
Coyotes are well-distributed in the Bronx, but crossing the Long Island Sound is still a significant barrier; only one coyote has established a permanent territory in Queens. However, we believe the establishment of a Queens/Long Island population is a matter of time.
Our analysis did not identify park size as a meaningful covariate. There may be a more complex relationship where area, habitat, and/or human activity play roles in determining the breeding suitability of a site. Research examining site quality and dispersal in NYC is ongoing.
Figure 1. New York City site map and coyote detection history,
Field methods - In , cameras were deployed in 10 parks in the Bronx (6 parks), Manhattan (1), and Queens (3; Figure 1). Camera density was kept at >2/km2.
In 2012, we deployed cameras continuously for 13.5 months. In 2013 and 2014 we conducted week studies in the winter and summer to sample the breeding (Apr 1 - Sept 30) and non-breeding (Oct 1 - Mar 31) seasons.
Analysis – Each season was divided into surveys of 2 weeks each for analysis. Single-season occupancy analyses were performed on each season individually, with multi-state analyses used on the 3 breeding seasons. Pups could not be observed in non-breeding seasons, which would have confounded a multi-season, multi-state analysis.
We modeled occupancy (ψ), the proportion of occupied sites with breeding (R), and detection (p) as constants and as functions of park size.
Figure 2. Seasonal occupancy (ψ) and breeding proportion (R) of coyotes in NYC Parks (mean ± SE) in breeding (B) and non-breeding (NB) seasons,
Acknowledgments: This research was supported by the Campfire Conservation Fund and the American Wildlife Conservation Foundation.
More info on the Gotham Coyote Project can be found at gothamcoyote.com