Heron Expansion in the Atacama Desert
1975; Oxford University Press; Volume: 92; Issue: 2 Linguagem: Inglês
10.2307/4084570
ISSN1938-4254
Autores Tópico(s)Archaeology and Natural History
ResumoAuk, Vol.92 either because a dead trunk or branch of the nest tree or repeated attacks by parent owls made close inspection dangerous, or because of inadequate illumination.Eggs of other species were not noticed or recorded in any of the 328 Great Horned Owl nests in which the senior author banded young before 1968.The presence of these eggs gave rise to some speculation.As the eggs were all cold and most were discolored and presumably there for some time, and as none were partially eaten, we surmise that neither adult nor young owls take advantage of this potential food source.It seems most unlikely• therefore, that the egg alone was brought to the nest.A prey individual might on occasion be alive when brought to the nest and expel an egg from its oviduct in its death throes.Another possibility is that a female bird had a fully formed egg in its oviduct when it was killed and brought to the nest; the young owls then devoured all the flesh around it, leaving the egg intact in the nest.The distal, but as yet uneaten, portion of a Pintail carcass (Anas acura) containing such an egg offers good evidence to support this latter possibility.In the latter half of May in Saskatchewan, peak food consumption by nestling owls coincides with a time of active egg-laying by coots and many ducks.
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