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Ferruginous Hawk (Buteo regalis) response to energy development and inclement weather in southern Alberta

  • Author / Creator
    Parayko, Nicholas W.
  • Growing global energy demand is projected to increase by nearly 30% in coming decades. As such, wildlife is increasingly required to persist in altered landscapes resulting from energy-related changes and development. In breeding birds, anthropogenic structures are often used as perches and, in many cases, are depended upon as nest supports. I investigated (1) the influence of temporary habitat alterations for energy development on a population of provincially Endangered Ferruginous Hawks (Buteo regalis), and (2) if artificial nest platforms (ANP) can mitigate the negative effects of extreme weather events on Ferruginous Hawk reproduction in southern Alberta, Canada. First, I applied a robust Before-During-After Control-Impact study design between 2013 and 2019 to assess the influence of three phases of transmission line development on the nesting density of the local study population, and examine whether temporary habitat alterations could result in a sink population or ecological trap. Using generalized linear and logistic mixed models, I found no differences in nest success, nest productivity, nest site reoccupancy, or community composition between or among treatment types. However, I reported a significant change in Ferruginous Hawk nest density following construction activities (tower addition or removal). Nest densities fluctuated positively with the number of transmission line towers present on the landscape. Though I found no evidence of an ecological trap, the influence of temporary alterations to nesting and perching substrates significantly influenced Ferruginous Hawk nest density. In addition to following existing industrial protocols for mitigation measures and post-construction monitoring, I recommend that future projects are proactive and begin monitoring activities at least 2 years prior to scheduled developments. Next, I investigated the effects of inclement weather during the Ferruginous Hawk breeding season and the importance of nest substrate on nest persistence, productivity, and the daily survival rate of nestlings (DSR). Variation in both timing and severity of extreme weather (wind, precipitation, and temperature) are predicted to increase under future climate scenarios. I used data from 8 years (2010–2017) of weekly nest monitoring to examine the influence of weather on 973 nesting attempts by pairs at 507 nests. Extreme wind events strongly influenced nest persistence rates, and DSR was significantly lower at sites with higher daily average wind speeds. Nest substrate type was also an important predictor of both nest persistence and DSR. Nests in ANPs had significantly higher survival rates where days with high average wind speeds and extreme wind events were more frequent. My results provide new insights and additional support for the use of ANPs as a practical and cost-effective management tool for open grassland raptors. I recommend that areas with both high daily average and extreme wind speeds receive higher priority when selecting sites for ANP installation.

  • Subjects / Keywords
  • Graduation date
    Spring 2021
  • Type of Item
    Thesis
  • Degree
    Master of Science
  • DOI
    https://doi.org/10.7939/r3-js8d-4a93
  • 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.