THE BEHAVIOUR, BREEDING, AND FOOD‐ECOLOGY OF THE SNOWY OWL NYCTEA SCANDIACA.

• Published in: Ibis
• Main Author: Watson, Adam
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1957
• Subjects: Baffin Island; Cumberland Peninsula; Baffin; Nyctea scandiaca; snowy owl
• Online Access: http://dx.doi.org/10.1111/j.1474-919x.1957.tb01959.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1474-919X.1957.tb01959.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1474-919X.1957.tb01959.x

Summary. During summer 1953, I studied Snowy Owls in Cumberland Peninsula, Baffin Island The wide range of call‐notes given by breeding owls is described Small passerines usually took little notice of the owls, though mobbing was common in July. The male owl usually chased other predators from his territory, which was exclusive of other Snowy Owls Some were shy of man, but others aggressive when disturbed at the nest, and males struck fiercely when they had young. Both sexes often did distraction display and displacement coition. Displacement feeding and hunting were also seen Threat and food‐begging, and the behaviour of the young in the nest, are described. The male brought all food to the female and young till about three weeks after the first young hatched, when the female also began to hunt The owls were confined to wet lowland areas where lemmings were abundant. Their density and breeding capacity were closely correlated with lemming density. Territories varied in size from a half to three or four square miles. One male was bigamous and five monogamous Nests were in prominent positions, and alternative sites used in previous years were found nearby Egg‐laying started in the third week of May as in most of the range. Mean clutch size was eight eggs The eggs hatched at different dates, resulting in a spread in development of the young. Most young left the nest in their fourth week; they began to fly short distances just after, but not well till about 60 days old, when they also began to hunt Proportionate changes in weight of the young were greatest in the first few days. On the whole they grew faster than young of various other predator species. Later‐hatched young tended to grow slower than earlier‐hatched young. All young that hatched also fledged, including 15 young in the one territory held by the bigamous male Each young ate an average of about two full‐grown lemmings a day while in the nest. Adults ate three to five each in a day, and in the London Zoo about 180 gm. each per day. An estimate was made ...