Long-eared Owls, <em>Asio otus</em>: A Review of North American Banding

DIFFERENTIAL mIGRATION BY SEx IN NORTH AmERICAN SHORT-EARED OWLS

Differential migration of the sexes is known in over 60 bird species and may be the predominant pattern in migratory birds. Identifying the causes of differential migration has been difficult, in part because sex-specific migratory patterns have yet to be described for a majority of species. We used the Internet specimen-data portal Ornis to compile sex-specific data on the seasonal distributio...

Social Behavior of North American Owls

Gloger’s rule in North American Barn Owls

Studying the geographic variation of phenotypic traits can provide key information about the potential adaptive function of alternative phenotypes. Gloger’s rule posits that animals should be darkvs. light-colored in warm and humid vs. cold and dry habitats, respectively. The rule is based on the assumption that melanin pigments and/or dark coloration confer selective advantages in warm and hum...

Snowy Owl Predation on Short-eared Owls

A problem confronting Snowy Owls (Nyctea scandiaca) in their southern incursions is the shortage of food. This difficulty is raised by the presence of other raptors that feed on small mammals. This note shows how little food is found by migrant Snowy Owls and indicates a complex temporary ecological solution. At Tatoosh Island, Washington (48”24’ N, 124” 44’ W) on 25 November 1973, we observed ...

West Nile Virus Outbreak in North American Owls, Ontario, 2002

From July to September 2002, an outbreak of West Nile virus (WNV) caused a high number of deaths in captive owls at the Owl Foundation, Vineland, Ontario, Canada. Peak death rates occurred in mid-August, and the epidemiologic curve resembled that of corvids in the surrounding Niagara region. The outbreak occurred in the midst of a louse fly (Icosta americana, family Hippoboscidae) infestation. ...