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Sex And Seasonal Differences In Cognition And The Brain In Brood-Parasitic Brown-Headed Cowbirds (Molothrus Ater), Mélanie F. Guigueno

Electronic Thesis and Dissertation Repository

The hypothesis underlying all of neuroecology proposes that natural selection can modify cognition and its neural mechanisms if these modifications enhance fitness. I tested for sex and seasonal differences in cognition and the brain of brood-parasitic brown-headed cowbirds (Molothrus ater) and the closely related non-brood-parasitic red-winged blackbird (Agelaius phoeniceus) to determine whether cognitive and neural patterns were associated with space use and singing in the wild. Cowbirds show a reversal of sex-typical space use often seen in mammals with only female cowbirds parasitizing, searching for, and revisiting host nests. Cowbird and blackbird males sing more than …