SPECIES

Snowy Owl Bubo scandiacus Scientific name definitions

Denver W. Holt, Matt D. Larson, Norman Smith, Dave L. Evans, and David F. Parmelee
Version: 1.0 — Published March 4, 2020

Figures from this Account

Distribution of the Snowy Owl
Figure 2. Schedule of breeding, migration, and molt for North American Snowy Owls.

Thick lines equal peak activity, thin lines off peak activity.

Figure 1. Breeding and wintering distribution of Snowy Owls in North America.
Figure 3. Frequency of Snowy Owl occurrence, Christmas Bird Counts 1960-1981.

Frequency = the proportion of counts reporting owls.

Figure 8. Snowy Owl Movements based on a summary of band recovery data.

Forty-one of 438 band encounters were encountered > 800 km from the banding location. Of these, 9 were banded at breeding latitudes from 4 different locations, the remaining 32 originating at banding sites at wintering latitudes. Straight line distance from bands associated with breeding locations averaged approximately 3200 km (1800-6000 km, n = 9). Most encounters > 800 km show general North-South directionality with no apparent longitudinal pattern. D. Holt.

Figure 4. Attitude of male during Territorial Hooting in May and early June.

Hooting males can be heard more than 2 miles away. By J. Zickefoose, after Taylor 1973.

Figure 9. Numbers of Snowy Owl Nests and Brown Lemmings caught during June trap session at ORI's longest running small mammal trap line (1992 to 2014).

Based upon 100 traps for 5 days = 500 trap nights. Snowy Owls did not nest in 1992, 1994, 1997, 1998, 2001, 2004, 2007, 2009, 2010, and 2013. Both regression lines (horizontal) suggest declining populations on Snowy Owls and Brown Lemmings. ⱡ No nests were found in 2007 and lemmings were not trapped (ORI unpublished data).

Figure 5. The aerial display used by males in courtship, an undulating flight over the tundra.

(A) The owl is shown at the point of delaying the wing beat, which results in his sinking before the next wing beat. (B) Side view. Drawing by J. Zickefoose, after Taylor 1973.

Figure 6. Ground display used by males during courtship.

(A) The early stage of the display is shown from the side. The posture is fairly erect. The owl may slowly turn or walk about on the ground carrying the lemming in his bill. (B) Transition from upright stance to lower stance in the ground display. When this posture is adopted, it frequently signals the closer approach of the female owl. By J. Zickefoose, after Taylor 1973.

Figure 7. Copulatory display of the female adopted before copulation; continued through and after a copulation.

Recommended Citation

Holt, D. W., M. D. Larson, N. Smith, D. L. Evans, and D. F. Parmelee (2020). Snowy Owl (Bubo scandiacus), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.snoowl1.01