Migration

Partial migrant. Thought to be highly migratory in northern part of its range. Nomadism in search of food, migration, and juvenile dispersal may be confused. Although present year-round at mid-latitudes, U.S. Fish and Wildlife Service band data indicate seasonal north/south migration and west/southwest movements for such individuals (Clark 1975).

In Europe, breeders above 50°N latitude usually migrate; those south of 50°N usually resident (Mikkola 1983). In the Galapagos Islands, De Vries (1973) found evidence of inter-island movements (see also Cramp 1985).

Routes not well known; can cross water -- 4 Short-eared Owls landed on board ships during autumn in the Pacific Ocean approximately 80, 800, and 1,088 km from land (Henshaw 1901, Bryan 1903, Gray 1945). Bryan (1903) believed that Hawaiian Short-eared Owls most likely originated from Alaskan stock. Distribution on oceanic islands illustrates this owl’s ability to migrate over vast expanses of ocean.

In the US, early dates of spring arrival, north of normal winter range (Bent 1938):

Alaska: Mt. McKinley – Apr. 10; Ft. Yukon – May 7

Quebec: Kamouraska – Apr. 10; Godbout – May 3

Manitoba: Treesbank – Mar 31; Margaret – Apr 5; Shoal Lake – Apr 30

Fall departure, late dates:

N. Dakota: Keene – Nov 2; Jamestown – Nov 17.

Alaska: St. Paul I. – Nov 8; Baranof I. – Nov 27. 

Ontario: Pt. Pelee – Nov 22; Port Dover – Nov 5; Ottawa – Nov 28.

In Europe (Czech Republic; Zvaral et al. 2005), 1997-2002, first fall migrants trapped in late Aug, with peak migration Oct - Nov; influx of new birds, nomadic wanderers, trapped Dec-Feb; total of 582 individuals trapped during this period.

Few data, but see above.

Not known.