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| Fig. 1. Estimated daily predation rates (±1 SE) for ground and aboveground nests of grassland passerines with and without cameras, during incubation and nestling stages, in Stutsman and Barnes Counties, North Dakota, 1996-97. Numbers of nests and exposure days for each group were as follows: camera-ground-incubation 15, 68.5; camera-ground-nestling 23, 152.0; camera-aboveground-incubation 15, 36.0; camera-aboveground-nestling 17, 105.5; non-camera-ground-incubation 78, 413.5; non-camera-ground-nestling 83, 552.0; non-camera-aboveground-incubation 162, 782.5; non-camera-aboveground-nestling 138, 788.0. |
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| Fig. 2. Digitized images captured from videotapes: (A) Mouse (probably Peromyscus maniculatus) killing 5-day-old clay-colored sparrow nestlings, (B) thirteen-lined ground squirrel killing adult female chestnut-collared longspur at the nest (ground squirrel had already removed 4 of 5 nestlings), (C) long-tailed weasel inspecting the camera after depredating common yellowthroat nest, (D) muzzle of white-tailed deer removing nestlings from Savannah sparrow nest (black mark on lower mandible is diagnostic), (E) female brown-headed cowbird removing egg from unattended western meadowlark nest (cowbird destroyed entire 5-egg clutch), and (F) 2-day-old western meadowlark crawling back into nest 12 hr after is was displaced by the adult female when she flushed from the nest during the night. |