Research
Molt dynamics
Feathers are amazing biological structures. The feathers of the wing and tail help to make the flapping flight of birds the most energetically-efficient form of locomotion among terrestrial vertebrates. The feathers of the body form a protective, insulative, and streamlined coat.
So, what happens when feathers inevitably wear out?
All birds replace their feathers periodically in a process
called “molt”, but species differ widely in terms of when,
where, and how quickly they molt. I conduct studies of
free-living birds, and studies using research specimens from museums, to illustrate the molt dynamics of populations and species, with the aims of understanding the ecological factors that have resulted in the evolutionary diversification of molt strategies, and the challenges of molting in a time of rapid global change.
Functional significance of structural variation in body feathers
Body feather structure varies greatly across birds (see the images below). We can expect that much of
this structural variation reflects functional variation (the rest probably reflects trade-offs associated with
feather production), but we know surprisingly little about how different body feather functions are
served by different body feather structures. I am interested in describing sources of variation in body
feather structure, and explaining their functional significance.
1 cm
1 cm
Adult American robin (Turdus migratorius)
Juvenile American robin (Turdus migratorius)
Physiological and behavioral effects of disturbance
Anyone who spends much time outdoors knows that it takes considerable effort to find large, contiguous landscapes that are undisturbed by humans. How do animals respond to the various forms of human disturbance, many of which are unpredictable? I am interested in the physiological and behavioral responses of birds to ecological and human disturbance. This work involves sampling birds for the stress-related hormone corticosterone, as well as other physiological and behavioral measures.
This file provides an explanation of the basics of taking blood from the wing of a small bird: BleedExplainer.pdf
Left wing of a molting Carolina Chickadee, showing new feathers (central 3 feathers), short, growing feathers (left-of-center) and old, worn feathers (left-most 3 feathers). Can you find the molting and old feathers on the inner wing?
A road bisecting prime habitat for the endangered Golden-cheeked Warbler (mature oak-juniper forest, central Texas).
