Merlin Parental Behavior and Chick Development as Revealed by Webcam

Abstract

Previous knowledge of the Merlin’s (Falco columbarius) nesting behavior was based on observation from the ground or data recorded during nest checks. Similarly, descriptions of chicks’ behavioral development were restricted to studies of captive birds. We used a webcam to observe adult Prairie Merlins (F. c. richardsonii) and their four young on an artificial nest platform located in Weyburn, Saskatchewan, from 25 April to 22 July 2020. Our observations extended from prior to egg-laying until 12 days after fledging, being most intensive after hatching. Activities revealed by the webcam largely confirmed previous ground-based observations and studies involving either nest visits or captive rearing. Eggs were laid at roughly 2-day intervals followed by a 30-day incubation period and a 31-day nestling period. The female dominated activity at the nest until the chicks achieved homeothermy (7–10 days after hatching); the male was seldom seen except when delivering prey to the female. The female stopped brooding chicks during the night after day 14 and during daylight on day 16. The male began bringing food directly to the chicks starting 17 days after hatching. The chicks’ development matched published reports with constant competition for food among chicks but also apparent efforts by the adult female to ensure that each chick received sufficient food. The webcam enabled us to gather more detailed information about the Merlin’s behavior at the nest than previously possible and provided an opportunity for citizen science involving a common but little studied falcon.