Gill lab @ WMU


© 2011 Sharon A. Gill.

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Last updated November 2013

Behavioral and hormonal responses to brood parasitism

One of the most fascinating reproductive strategies among animals is brood parasitism in which the parasite leaves its offspring to be cared for by unrelated adults, often of a different species. The most widespread avian brood parasite in North America is the brown-headed cowbird, which have been recorded parasitizing over 200 species across its range. For my MSc research, I investigated interactions between cowbirds and a common host, the yellow warbler. Yellow warblers are unusual in how they respond to cowbirds - giving a specialized alarm call and performing a type of nest-protection behavior which limits the access of cowbirds to the nest  - compared with their generalized response to other birds around their nests. We’ve been exploring these responses in more detail as well as asking whether there are hormonal changes associated with being parasitized.


Photo by A. Bierema

All in the family: understanding natal dispersal and genetic structure of neotropical wrens

During my doctoral and post-doc research, I studied buff-breasted wrens, a neotropical species that shows a unique and understudied form of social behavior. These birds live in family groups for most of the year, which in itself isn’t that unusual, but unlike most birds with this social structure, there is no cooperative breeding. To understand the evolution of social behavior, studies of family living but non-cooperative species are important because they allow researchers to target the key question of why offspring stay for prolonged periods with their parents, which has been a vexing issue for many years. My previous work in this system has included studies on genetic and social mating systems, parental effort, and duetting. We are currently investigating the influence of short-distance natal dispersal on fine-scale genetic structure, social evolution within the wren clade, and a comparison of life history with closely related temperate Carolina wrens in collaboration with Thomas Haggerty at the University of Northern Alabama.


Life in the city: what contributes to species persistence in urban landscapes?

Photo by S. Alessi

The United Nations projects that by 2050 more than 5 billion people will live in cities. During the process of urbanization, natural landscapes are converted to human-dominated ecosystems, and the resulting landscapes are warmer, more polluted, and are less biologically diverse than natural landscapes. We are interested in understanding organismal-level processes that underlie the persistence of native species in urban centers, and are currently focusing on behavior and physiology of birds in urban and natural landscapes. Our primary study species is the chipping sparrow, a species that has apparently increased with urbanization and is widespread in urban areas in Michigan and throughout its range. This year, we’ll also be studying frogs along an urbanization gradient.

Photo by MDF used under GNU Free Documentation License.