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Unraveling A Paradox Of Habitat Relationships: Scale-Dependent Drivers Of Temporal Occupancy-Abundance Relationships In A Cooperatively Breeding Bird, Natasha D.G. Hagemeyer, Mario B. Pesendorfer, Walter D. Koenig, Eric L. Walters

Biological Sciences Faculty Publications

Context Spatial occupancy and local abundance of species often positively covary, but the mechanisms driving this widespread relationship are poorly understood. Resource dynamics and habitat changes have been suggested as potential drivers, but long-term studies relating them to abundance and occupancy are rare. In this 34-year study of acorn woodpeckers (Melanerpes formicivorus), a cooperatively breeding species, we observed a paradoxical response to changes in habitat composition: despite a reduction in the availability of high-quality breeding habitat, the population increased considerably.

Objectives We investigated the role of annual variation in food availability and long-term changes in habitat composition as predictors …

Lifetime Inclusive Fitness Effects Of Cooperative Polygamy In The Acorn Woodpecker, Walter D. Koenig, Sahas Barve, Joseph Haydock, Eric L. Walters

Biological Sciences Faculty Publications

Although over 50 y have passed since W. D. Hamilton articulated kin selection and inclusive fitness as evolutionary explanations for altruistic behavior, quantifying inclusive fitness continues to be challenging. Here, using 30 y of data and two alternative methods, we outline an approach to measure lifetime inclusive fitness effects of cooperative polygamy (mate-sharing or cobreeding) in the cooperatively breeding acorn woodpecker Melanerpes formicivorus. For both sexes, the number of offspring (observed direct fitness) declined while the number of young parented by related cobreeders (observed indirect fitness effect) increased with cobreeding coalition size. Combining these two factors, the observed inclusive …