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