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

Tables and Appendices

Table 1

Snowy Owl Morphometric Data from North American Winter Studies.

The data in Table 1 are the result of several dedicated researchers who spend their winters trapping and banding Snowy owls. This is the largest data set of winter body mass records on live Snowy Owls anywhere in the world. Collectively these researchers provided ~150 years of experience.

LocationMean Live MassMean ChordMean Tail
Maleg (n)mm (n)mm (n)
Massachussets11674.2 (286)386.9 (286)223.3 (286)
Minnesota21657.0 (170)393.9 (170)209.6 (160)
New York31596.9 (197)393.1 (197)223.1 (143)
Alberta41525.5 ( 26 )385.5 ( 26 )204.6 ( 26 )
Alberta51650.9 (162)396.0 (165)217.9 (162)
Saskatchewan61600.9 (154)392.7 (153)209.8 (137)
Total1636.9 (995)391.7 (869)217.4 (914)
Femaleg (n)mm (n)mm (n)
Massachussets12128.4 (165)424.3 (165)239.7 (165)
Minnesota22179.9 (262)429.5 (262)225.9 (252)
New York32087.3 (196)434.4 (196)246.3 (142)
Alberta41893.2 ( 69 )420.1 ( 69 )219.3 ( 69 )
Alberta52096.1 (289)428.6 (292)236.6 (288)
Saskatchewan62119.0 (208)428.6 (206)226.5 (188)
Total2109.8 (1189)428.6 (1190)233.5 (1034)

Source:

1Norman Smith, unpublished data; 2David Evans, unpublished data; 3Thomas McDonald, unpublished data; 4Mike Blom, unpublished data; 5Hardy Pletz, unpublished data; 6Dan Zazelenchuk, unpublished data.

Table 2

Food-niche breadth and dietary evenness of Snowy Owls.

Food-niche breadth (FNB) and dietary evenness (DIEV) of Snowy Owls from seven North American studies reporting 100 or more prey items, representing 5888 prey. Only prey identified to species were used in the calculations.

LocationNo. Prey% Mammals% Microtusa% AvianFNBDIEVSource
Montana4680 99.899.5 0.21.280.428Detienne et. al. 2008
Ontario, Can314 100 90.4 0.01.490.441Catling 1973
Alberta, Can24093.3 29.9 6.73.260.647Boxall and Lein 1982
Br. Col., Can2120.0 0.01007.730.584Campbell & MacColl 1978
Michigan185100 85.90.0 1.650.509Chamberlin 1980
New England13651.525.747.813.850.559Gross 1944
Michigan12199.266.70.82.990.552Allan 1977
Mean4.610.531
SD±4.64±0.078

a % Microtus = % of Mammals that are Microtus spp.

Source: Detienne et. al 2008

Table 3

Measures of Snowy Owl reproductive success.

Measures of Snowy Owl reproductive success at Barrow, AK (1993-2014). Number of nests, eggs, or nestlings given in parentheses (Owl Research Institute, unpublished data)

YearAverage Clutch SizeHatching Success1Nestling Success2Minimum Fledging Success3Maximum Fledging Success4
19936 (18)79 (100)84 (79)18 (79)66 (79)
19955 (48)69 (232)63 (160)46 (160)52 (160)
19967 (19)90 (129)66 (116)62 (116)63 (116)
19995 (26)59 (127)57 (75)45 (75)55 (75)
20006 (15)73 (91)83 (66)62 (66)76 (66)
20025 (4)76 (21)31 (16)19 (16)19 (16)
20036 (6)39 (38)47 (15)13 (15)27 (15)
20058 (4)77 (30)61 (23)48 (23)57 (23)
20066 (35)91 (216)87 (196)32 (196)80 (196)
20086 (31)87 (175)85 (152)78 (152)80 (152)
20116 (3)61 (18)73 (11) 73 (11)73 (11)
20126 (11)69 (68)74 (47)62 (47)68 (47)
20146 (19)51 (114)50 (58)40 (58)45 (58)
Total6 (239)75 (1359)73 (1014)48 (1014)65 (1014)

1Percent eggs laid that hatched

2Percent nestlings hatched that dispersed from nest

3Percent nestlings hatched that were confirmed to fledged

4Percent nestlings hatched that were presumed to fledge based on age of last observation

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