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Full-Text Articles in Life Sciences
The Breeding Biology Of The Northern Pygmy Owl: Do The Smallest Of The Small Have An Advantage?, John F. Deshler, Michael T. Murphy
The Breeding Biology Of The Northern Pygmy Owl: Do The Smallest Of The Small Have An Advantage?, John F. Deshler, Michael T. Murphy
Biology Faculty Publications and Presentations
We explored the breeding biology of the Northern Pygmy-Owl (Glaucidium gnoma) from 2007 to 2009 in a forested reserve in Portland, Oregon. Large body size is often assumed to give animals reproductive advantages, and we tested whether body size affected timing of breeding and examined variation in diet, breeding date, clutch size, and reproductive success to explore whether the presumed benefits of large body size are evident in this species. The average size of 13 clutches was 5.8, and nest success was high (92%); 22 successful nests fledged an average of 5.2 young. Dates of first laying varied …
Lifetime Reproductive Success Of Female Eastern Kingbirds (Tyrannus Tyrannus): Influence Of Lifespan, Nest Predation And Body Size, Michael T. Murphy
Lifetime Reproductive Success Of Female Eastern Kingbirds (Tyrannus Tyrannus): Influence Of Lifespan, Nest Predation And Body Size, Michael T. Murphy
Biology Faculty Publications and Presentations
I report on the lifetime reproductive success (LRS) of female Eastern Kingbirds (Tyrannus tyrannus) in central New York. I investigated the major correlates of LRS and specifi cally tested the hypothesis that small body size yields reproductive benefi ts. Lifetime reproductive success varied widely: 15–20% of females failed to fledge young over their life, whereas 50% of young were fledged by 20% of females. Female lifespan varied between one and eight years, and females that died after one breeding season tended to be smaller-bodied than long-lived females (≥2 seasons). I therefore conducted analyses of LRS for the entire sample and …