Human-Wildlife Interactions (Sep 2017)
Evaluating Lethal and Nonlethal Management Options for Urban Coyotes
Abstract
Human-coyote conflict in urban environments is a growing issue in cities throughout the United States with the primary problem being the development of problem individuals that are overly bold and aggressive with people and pets. Little research has focused on management options to deal with this conflict. We better define lethal and nonlethal management strategies associated with proactive and reactive management of coyotes with an emphasis on management of problem individuals. We then provide data from research in the Denver Metropolitan Area (DMA) that focused on reactive lethal removal of problem coyotes and reactive nonlethal hazing (i.e., community-level hazing, a commonly recommended strategy that we better define). The primary lethal management strategy being used in the DMA is to remove problem coyotes only when severe conflict (primarily threats to people) occurs. From 2009-2014 there were 27 removal events (4.5/year) with the average number of coyotes removed per event being 2.1 (range 1 – 11) and the average number of coyotes removed per year being 9.3. The estimated percentage of coyotes removed per year from the population was between 1.0 and 1.8%. We also measured recurrence of conflict (i.e., length of time until another severe conflict occurred in the vicinity of a removal event) as a measure of efficacy. Of the 27 removals, there were nine with recurrence with an average of 245 days (range 30-546) between removals, and 18 events without recurrence and with a mean time since conflict event of 1,042 days (range 133-2,159). For our community-level hazing experiment we used wildlife cameras to record activity of both people and coyotes at four sites (two treatment and two control). At treatment sites with prior history of conflict, we educated and encouraged people to haze visible coyotes and hypothesized that hazing would decrease the activity overlap between people and coyotes on treatment sites. We recorded over 50,000 independent sightings of people and coyotes and found activity overlap between humans and coyotes to be either similar or greater on treatment sites compared to control sites. Our results indicate that reactive nonlethal hazing as conducted in this study was ineffective in reducing human-coyote activity overlap. However, due to a variety of reasons we detail below, we encourage readers to interpret the hazing results with caution. We conclude that reactive lethal removal of problem individuals is an effective means of managing conflict and that proactive nonlethal strategies are critical as well.
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