Ecology of wintering Canada geese in the greater Chicago metropolitan area

• Main Author: Dorak, Brett Eugene
• Other Authors: Ward, Michael P., Eichholz, Michael W., Hagy, Heath M.
• Format: Text
• Language: English
• Published: 2016
• Subjects: Canada geese; urban; habitat selection; survival; movements; Canada; Branta canadensis; Subarctic
• Online Access: http://hdl.handle.net/2142/95265

Canada geese (Branta canadensis) breed in subarctic and temperate areas of North America, but both populations typically winter in temperate regions of the northern United States. During winter, Canada geese are increasingly using urban areas, but data are lacking on habitat use and selection, movements, potential thermal benefits of selected habitats, and survival of Canada geese during late autumn and winter in urban areas. I captured Canada geese during November‒February 2014‒2016 in the Greater Chicago Metropolitan Area (GCMA) in northeastern, Illinois, USA and fitted 41 geese with solar-powered GPS transmitters. Neck collar-mounted transmitters operated on the cellular phone network and collected hourly locations (n = 39,392). Canada geese selected green spaces (59.8%) in greater proportion than available (14%), but I also documented geese using novel habitats such as rooftops and rail yards (i.e., industrial urban; 11.3%). Habitat use shifted away from green spaces (36%) to industrial urban habitats (10.4%), riverine (12.8%), and deep-water habitats (37.8%) as temperatures decreased below the lower critical limit for Canada geese (i.e., temperature at which increased thermoregulatory costs are incurred to maintain core body temperature). During periods when temperature decreased and snow depth increased geese increasingly used industrial urban habitats. Both snow depth and minimum daily temperatures were associated with decreased movement distances within habitats. Movements by Canada geese within rail yard (x̅ = 224.0 m, SE = 13.0) and green space habitats (x̅ = 145.6 m, SE = 3.4) were the longest for any habitat type, while movements by geese in deep-water habitats (x̅ = 85.7 m, SE = 3) and rooftop habitats (x̅ = 52.9 m, SE = 5.5) were the shortest. When temperatures were below the lower critical temperature (-6 ⁰C) Canada geese transitioned from deep-water to green space habitat in greater proportion than all other possible transitions between habitat types. Proportion of use of green space habitat ...