Cooper’s hawk nest success relative to habitat disturbance
Cooper’s hawks can survive in urban environments, but suffer from urban related factors such as collisions with windows and cars, and potential disturbance from people, pets, and ambient noise from traffic. We surveyed 45 sites in May and June 2014 that had active Cooper’s hawk nests in 2013 order to determine if there was an association between whether a nest was active and the level of disturbance at the site. Nest sites were classified as low, medium, or high disturbance, based upon levels of noise and physical pollution, human presence, urbanization, and traffic. After classifying a site, we spent 10 to 15 minutes searching for the presence of a Coopers hawk. A nest was deemed active if a Cooper’s hawk was seen or heard. The percentage of successful and unsuccessful nests per disturbance was then calculated.
We classified 7 of the 45 sites were classified as low disturbance, 24 of the sites were medium disturbance and the remaining 14 sites were high disturbance. Percentages of active nests within each category of disturbance were similar (low disturbance, 57%; medium disturbance, 58%; and high disturbance 50%). There is not a significant change in nest success rate between levels of disturbance. Level of disturbance did not appear to have a significant influence on whether Cooper’s hawks in Tucson began nesting activities.