Habitat use, dispersal and survivorship of juvenile Peregrine Falcons (Falco peregrinus) from Manitoba

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Martinez-Welgan, Isabel Michelle
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Satellite tracking technology was used to acquire previously unavailable data relating to habitat use, dispersal and survivorship of juvenile Peregrine Falcons, a species currently designated as “Endangered” in Manitoba. A partnership between Manitoba Conservation, Manitoba Hydro, the Sustainable Development Innovations Fund of the Province of Manitoba, Parkland Mews Falconry and Bird of Prey Education Centre, and the University of Manitoba facilitated the purchase and deployment of twenty solar-powered Global Positioning System-enabled Platform Transmitting Terminals (PTTs). Thirty Peregrine Falcons were equipped with PTTs between 2011 and 2013, including both wild and hacked falcons. Home range analysis based on kernel density estimation identified a space-filling pattern of landscape use as peregrines dispersed from the natal areas. Habitat associations determined for PTT-equipped peregrines confirm their association with open habitats, human developments and aquatic areas. Conversely, peregrines were generally not found in areas characterized by dense tree cover. Throughout the study area, juvenile falcons readily utilized human features including the support structures comprising the Manitoba Hydro Distribution and Sub-Transmission Line network. The period following fledging and dispersal from the natal area was characterized by expansive movement quantified using a Brownian Bridge Movement Model. The importance of the natal area was evident throughout the dispersal period. Fifteen falcons (50%) survived to initiate fall migration. Of these, ten (33%) successfully reached wintering grounds located in the United States, Mexico, and Belize. Four Peregrine Falcons were confirmed alive to project end (13%). Sixteen of 30 Peregrine Falcons were confirmed dead during the study period (53%); mortality was suspected for seven others (23%). Survivorship outcomes could not be determined for three falcons (10%). All of the observed mortality occurred during the first year of life. Although the annual production of peregrines in Manitoba currently shows an increasing trend, the population has not yet demonstrated the stability and growth to be considered secure. Ensuring a stable population will require continued active management. The provincial population may also benefit from supplementation based on delayed hack techniques.
Falco peregrinus, Peregrine Falcon, Habitat use, Mortality, Juvenile dispersal, Survival, Migration