A live broadcast of a peregrine falcon nesting at the University of Pittsburgh's Cathedral of Learning shows the bird feeding three hatchlings to her first chick.
The Pittsburgh Post-Gazette reports thousands watched the infanticides over recent days through a National Aviary stream.
Ornithologist Bob Mulvihill says scientists don't yet know whether to consider the acts "abhorrent.''
The falcon, Hope, was incubating two eggs in March when her mate was found dead. She laid a third egg days later that was fertilized by that male. A fourth sired by another male was later laid.
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Mulvihill says the first egg hatched and that Hope fed the second and third to the first. She killed the fourth while it hatched, ate part of it and fed the rest to the lone survivor.