Effect of Coyotes on Urban Canada Geese Nest Dynamics in the Chicago Metropolitan Area

Justin Brown, M.S. Candidate
Advisor: Stan Gehrt

Predator-prey relationships between wildlife species are often poorly understood, especially in urban landscapes. We are going to identify important predators of Canada geese (Branta canadensis) nests in an urban landscape, with a specific focus on coyotes (Canis latrans), and their possible role as a biological control for urban geese. High nest success resulting from low predator density in urban and suburban settings is often cited as one of the reasons for the rapid growth of urban goose populations. A previous study on goose nesting success in this same area found nest depredation was the most common cause of nest failure (59% of failures), followed by desertion, flooding and egg failure, respectively. An on-going project focusing on coyote ecology using radio telemetry in the Chicago metropolitan area was initiated concurrent with the goose project. This study has documented habitat use by coyotes in the same area where the goose study was conducted. Currently ~25 coyotes are radio tracked each year in the NW Chicago metropolitan area as a continuation of the coyote study, and we will relate coyote land use to nest predation. Nest predation will be recorded using multiple methods: infrared (IR) time lapse video cameras, motion sensitive IR still cameras, and hollow domestic goose eggs filled with plasticine tied onto a stake at the bottom of the nest with braided fishing line. Nests in different landscape types will be monitored to determine the relationship between landscape use and coyote predation. Information from these relationships will be incorporated into an existing model of Canada goose population dynamics to determine the relative importance of coyotes for the population growth of resident urban Canada geese in the Chicago metropolitan area.

Funding Sources: Cook County Animal and Rabies Control, Max McGraw Wildlife Foundation