Title
A Comparison of Direct Observations and Collections of Prey Remains in Determining the Diet of Golden Eagles
Document Type
Tech Pub
Publication Date
4-1-1983
Journal Title/Publication Source
Journal of Wildlife Management
Volume
47
Issue Number
2
Page Numbers
360-368
Abstract
Two techniques were used to determine the diets of 4 pairs of nesting golden eagles (Aquila chrysaetos) in southwestern Idaho during 1978 and 1979; direct observations of prey deliveries to nests were compared with estimates of food habits derived from analyses of systematic collections of pellet and prey remains. There was no difference (P > 0.05) between the 2 methods in the estimated species composition, either by percent frequency or percent biomass. Comparisons of the daily capture rates derived using the 2 techniques demonstrated that collections of pellet and prey remains consistently underestimated observed prey delivery. Estimates of the time period collections reflected prey deliveries ranged from 1.6 to 5.5 days, but were consistent for each nest. Periodic observations of food delivery at nest sites can be used to correct for prey biomass unaccounted for in the collections; this procedure would enable researchers to use collections of pellet and prey remains to estimate prey biomass delivered to nests.
Publication Information
Collopy, Michael W., "A Comparison of Direct Observations and Collections of Prey Remains in Determining the Diet of Golden Eagles" (1983).
Journal of Wildlife Management
, 47 (2), 360-368
https://scholarworks.boisestate.edu/bop/Bibliography/Bibliography/106
A Comparison of Direct Observations and Collections of Prey Remains in Determining the Diet of Golden Eagles
Two techniques were used to determine the diets of 4 pairs of nesting golden eagles (Aquila chrysaetos) in southwestern Idaho during 1978 and 1979; direct observations of prey deliveries to nests were compared with estimates of food habits derived from analyses of systematic collections of pellet and prey remains. There was no difference (P > 0.05) between the 2 methods in the estimated species composition, either by percent frequency or percent biomass. Comparisons of the daily capture rates derived using the 2 techniques demonstrated that collections of pellet and prey remains consistently underestimated observed prey delivery. Estimates of the time period collections reflected prey deliveries ranged from 1.6 to 5.5 days, but were consistent for each nest. Periodic observations of food delivery at nest sites can be used to correct for prey biomass unaccounted for in the collections; this procedure would enable researchers to use collections of pellet and prey remains to estimate prey biomass delivered to nests.