Does prey availability affect the reproductive performance of Barn Swallows (Hirundo rustica) breeding in Ontario, Canada? (original) (raw)

Animal populations are often limited by food availability, particularly during the breeding season. In birds, food limitation can impact several components of the reproductive cycle, including the timing of reproduction and reproductive output. Barn Swallows (Hirundo rustica Linnaeus, 1758) have experienced a population decline over the past 40 years in North America that is thought to be related to changes in prey availability. We monitored Barn Swallow reproductive behaviour and prey availability throughout two breeding seasons at 10 sites in Ontario, Canada, to test the hypothesis that limited prey availability during the breeding season affected reproductive behaviour. We found no relationship between food availability and number of eggs laid or number of young fledged. Neither did we observe higher rates of second brooding or more pairs nesting at breeding sites with higher food availability. Barn Swallows did not time their reproductive effort to maximize prey availability dur...