Influence of Anthropogenic Development on Burrowing Owl Habitat Selection, Survival, and Reproductive Success

• Author / Creator

  Scobie, Corey A

• Anthropogenic development may influence the choices animals make and their resulting reproductive success and survival. If such choices are maladaptive, the impact of changes to their habitat could be catastrophic to populations that are small or declining. The Canadian prairies have changed dramatically since European settlement. Over two thirds have been converted to cropland and the number of petroleum wells within the Burrowing Owl range has tripled over the last thirty years. It is assumed that the decline of the Burrowing Owl is linked to these changes to the prairie landscape, but so far no clear, direct links have been identified. I examined habitat selection of Burrowing Owls at several temporal and spatial scales and evaluated how habitat selection influenced survival and reproductive success. First, I identified landscape features that Burrowing Owls prefer to have surrounding their nests, and examined how these preferred features related to nest survival, fledging rate, and adult survival. Using arrival date as a measure of preference, I found Burrowing Owls prefer home ranges with more annual crop and more road surfaces. These anthropogenic landscape features had a positive influence on fledging rate, suggesting that these landscape features have not created an ecological trap for Burrowing Owls on the Canadian prairies at the home range scale. Second, I tracked adult male Burrowing Owls with GPS dataloggers and examined owl space-use during the day and night. During the day, Burrowing Owls spent more time near fences and posts, likely because they are good vantage points for detection of predators. They also avoided roads with high traffic speeds, possibly because auditory disturbance from passing vehicles interferes with their ability to communicate the presence of predators to their mates and young. At night, the infrastructure (towns, roads, petroleum facilities, and oil wells) that results from human development influenced where owls spent time much more than did sensory disturbances (artificial sound and light) emanating from these sources. However, owl selection of landscape features at night did not predict reproductive success. Instead, I found owls that spent more time near the nest burrow between sunset and sunrise had the greatest nest survival and fledging rates. The choices this endangered owl makes when hunting at night and when picking a landscape in which to settle do not seem to be maladaptive or fully explain their population decline in Canada. To better understand the Burrowing Owl decline, future studies need to focus on life history stages not examined here (e.g. post-fledging for juveniles), as well as stages that occur outside of their breeding range. My findings indicate that the Burrowing Owl has flexible habitat requirements and is able to breed successfully in a developed landscape. Such determinations will be important to make for a variety of other species to identify those that may be less likely to be able to adapt to changing landscapes.

• Subjects / Keywords

  • Burrowing Owl
  • Anthropogenic development
  • Ecological trap
  • Resource selection
  • Habitat selection

• Graduation date

  Fall 2015

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R36T0H75R

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.