Effects of Harassment on Behavior and Movement of Canada Geese (Branta canadensis) in an Urban Park

Increasing abundances of Canada geese (Branta canadensis) wintering in urban areas have led to a host of human-wildlife conflicts including feces deposition, human health risks, and aircraft collisions. Harassment is the primary tool wildlife managers use to deal with nuisance goose abundances yet has been deemed ineffective at changing goose abundances in an area or reducing issues in longer time periods. However, the effects of harassment at the individual level are poorly studied, especially in winter when harassment may have more dire consequences. The objectives of this study were to examine the effects of targeted harassment on 1) average daily movement distances, 2) habitat use, and 3) overall dynamic body acceleration (ODBA) as an index of energetic expenditure. To examine effects of harassment on individual Canada geese we used data from 41 geese marked with GPS transmitters in the Chicago Metropolitan Area. Harassment efforts were conducted December 2017- February 2018 by US Department of Agriculture – Wildlife Services personnel at an urban park near Midway International Airport as part of ongoing efforts to reduce risk to air traffic. We compared average daily movement distance and ODBA of geese that in and out of harassment areas. In addition, we quantified differences in proportional habitat use of geese between treatments. Canada geese subjected to harassment moved more than unharassed geese in December (x¯$_harassed $= 338.2 ± 19.3 SE, x¯$_unharassed $= 211.3 ± 8.4 SE), January (x¯$_harassed $= 409.0 ± 2.5 SE, x¯$_unharassed $= 269.0 ± 11.0 SE), and February (x¯$_harassed $= 447.0 ± 36.4 SE, x¯$_unharassed $= 232.8 ± 13.5 SE). Results of this study suggest that winter harassment of Canada geese in winter has effects on the behavior and energetic expenditure that could result in lower survival and reduced conflicts in urban parks where targeted harassment is conducted.