2000 – Present: Adaptation and Evolution of Plumage Pattern in Myioborus Redstarts
The Myioborus redstarts (also known as whitestarts) comprise 12 species of small insectivorous birds ranging from the southwestern United States to the southern Andes. All 12 species are noted for their white outer tail feathers and their animated foraging displays designed to startle and flush potential insect prey, which can then be pursued and captured in flight. During a spring 2000 sabbatic leave, I initiated a study of the flush-pursuit foraging behavior of the Slate-throated Redstart (Myioborus miniatus) in Monteverde, Costa Rica. I used tail-dyeing experiments to demonstrate that the white outer tail feathers are critical to flush-pursuit foraging success; experimental darkening of tail feathers significantly reduced the probability of flushing potential prey, prey attack rates, and feeding rates at nests. In collaboration with Piotr Jablonski of the University of Arizona, I am currently trying to understand the complex pattern of interspecific and intraspecific geographic variation in the amount of white in the tail and wings of Myioborus redstarts. My research in Costa Rica has been supported by a grant from the Committee for Research and Exploration of the National Geographic Society.
Selected Publications
Previous Research
1986 – 2000: Behavioral Ecology and Conservation Biology of the Florida Scrub-Jay (Aphelocoma coerulescens)
For 15 years my research focused on the behavioral ecology and conservation biology of the Florida Scrub-Jay (Aphelocoma coerulescens), a threatened species that is restricted to the unique oak scrub of peninsular Florida. My research was designed to extend and complement the long-term demographic studies of this species by Glen E. Woolfenden, John W. Fitzpatrick, and their colleagues at Archbold Biological Station in Highlands County, Florida. Florida Scrub Jays are permanently monogamous and permanently territorial. About half of all breeding pairs share their territories with 1-6 nonbreeders that are usually independent offspring of the breeding pair and that usually act as helpers by assisting the resident breeders in rearing the young of subsequent broods. My research pursued four general themes; (1) an experimental analysis of the role of helpers in enhancing reproductive success of recipient breeders, (2) examination of the endocrinological basis of breeding suppression and helping behavior (in collaboration with Steve Schoech of the University of Memphis), (3) the demographic consequences of road mortality on source-sink population dynamics, and (4) the utility of translocation as a technique for restoration of this threatened and declining species.
Selected Publications
1978-1986: Behavioral Ecology of the Acorn Woodpecker (Melanerpes formicivorus)
For my Ph.D. dissertation research at the University of California, Berkeley, I participated in a long-term study of the ecology and social behavior of the Acorn Woodpecker at Hastings Natural History Reservation in the upper Carmel Valley, Monterey County, California. The Acorn Woodpecker has perhaps the most complex social system of any North American bird; it lives in permanently territorial family groups of 2-15 birds, generally containing 1-2 breeding females, 1-4 breeding males, and 0-10 nonbreeders that are typically group offspring produced in previous breeding seasons. In groups containing two co-breeding females (usually sisters or mother-daughter combinations), both females lay eggs in a single nest and cooperate to rear the young, a phenomenon called joint nesting. Similarly, in groups with two or more co-breeding males, the males are closely related (brothers or father-son combinations) and compete with one another for access to females during her fertile period prior to egg laying. My dissertation research focused on the mix of cooperation and competition that characterized this species' complex social system.
Selected Publications
• Koenig, W. D., and R. L. Mumme. 1997. The great woodpecker egg-destruction derby. Natural History 106 (5): 32-37.
• Koenig, W. D., P. B. Stacey, M. T. Stanback, and R. L. Mumme. 1995. Acorn Woodpecker (Melanerpes formicivorus). In The Birds of North America, No. 194 (A. Poole and F. B. Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The American Ornithologists’ Union, Washington, D. C.
• Koenig, W. D., and R. L. Mumme. 1987. Population ecology of the cooperatively breeding Acorn Woodpecker. Monographs in Population Biology 24, Princeton University Press.
