Research Interests

An animal's ability to move influences every aspect of its behavior, ecology, and evolution. At the most superficial level, locomotion is the ability of an animal to interact with its medium. However, locomotion is made possible by a complex set of well timed processes that include the ability to convert metabolic energy to mechanical work, the response loops used to react to external feedback, and the structures used to interact with the environment. Each of these processes is constrained by the fundamental laws of physics and chemistry, but is also the target of strong selective pressure because any failure can be fatal. I am interested in questions that look at the physical limitations of size and shape, and the real-world consequences of locomotor performance during high-stakes behavior in aquatic, aerial, and terrestrial organisms. My research interests include the following questions:

1) How do size and shape influence aquatic maneuvering performance? In spite of their enormous size, whales make their living as the world's largest predators. To catch their much smaller, more maneuverable prey, they have developed several unique locomotor strategies that require high energetic input, high mechanical power output, and a surprising degree of agility. Using non-invasive, suction-cup attached bio-loggers outfitted with accelerometers, magnetometers, and gyroscopes we can analyze maneuvering performance across several axes of motion. Understanding how cetaceans move across different geographic and temporal scales will help us understand how marine mammal populations are responding to changing environmental and climatic conditions. In collaboration with the Goldbogen Lab at Stanford University.

2) What is the relationship between morphology, physiology, maneuverability, and competitive success? Maneuverability, or the ability to change speed and direction, is thought to play an important role in competition, courtship, hunting and foraging, territory defense, escape from predation, and a variety of other behaviors. However, since maneuverability is rapid, dynamic and difficult to quantify, the mechanical and physiological basis for maneuvering performance is not well understood. My research on hummingbird maneuverability has used automated video tracking to demonstrate that: 1) individual maneuvering performance is directly related to the ability of the muscles to produce burst, anaerobic power; 2) as elevation increases, the ability to translate muscular power to aerodynamic power is reduced by the lower air density; and 3) across species of tropical hummingbirds, differential ability to produce burst muscular force results in different maneuvering capabilities. In collaboration with the Altshuler Lab at the University of British Columbia.

3) How do juvenile birds manage the trade-offs associated with growth and development while transitioning from terrestrial to aerial locomotion? During their fledgling stages juvenile birds undergo rapid physiological, neurological, and kinematic development as they transition from hindlimb dominated to forelimb dominated locomotor strategies. The length of this developmental period varies widely across species with different evolutionary lineages and life history strategies across the altricial-precocial spectrum. My research focuses on the kinematic and behavioral strategies that different species use to negotiate this critical life stage, both in a controlled laboratory environment and in their natural habitat. These types of studies on avian locomotor development for escape, foraging, and dispersal may explain much about the diversity of adult avian phenotypes. In collaboration with the University of Montana Flight Lab.