Postdoctoral Fellow / Migratory Bird Center
My current research focuses on birds' needs to acquire, maintain, and release energy, and how the interplay among the requirements influences their ecology and evolution. In particular, I'm investigating the selection pressures that these potentially conflicting requirements exert on bill morphology. I'm using the song sparrow as a study species, including 2 subspecies: the eastern song sparrow (Melospiza melodia melodia), which inhabits much of the eastern USA and has a smaller bill, and the Atlantic song sparrow (Melospiza melodia atlantica), which lives a short distance away, only in sand dunes along the Atlantic coast, and has a larger bill. My approaches are experimental, observational, and comparative, and employ developmental biology, functional morphology, and population genetics.
Danner, Raymond M. and Greenberg, Russell. A critical season approach to Allen's rule: bill size declines with winter temperature in a cold temperate environment, Journal of Biogeography, . 2014.
Danner, Raymond M., Greenberg, Russell, Danner, Julie, Kirkpatrick, Laila T. and Walters, Jeffrey R. Experimental support for food limitation of a short-distance migratory bird wintering in the temperate zone, Ecology, 94 (12) 2803-2816. 2013.
Greenberg, R. and Danner, R. M. Climate, ecological release and bill dimorphism in an island songbird, Biology Letters, 9 (3) 20130118. 2013.
Greenberg, Russell, Etterson, Matthew and Danner, Raymond M. Seasonal dimorphism in the horny bills of sparrows, Ecology and Evolution, 3 (2) 389-398. 2013.
Greenberg, Russell S. and Danner, Raymond M. The influence of the California marine layer on bill size in a generalist songbird, Evolution, 66 (12) 3825-3835. 2012.