Animal Performance in nature
An earless lizard from Arizona. Photo by D. J. Irschick
One of the most basic questions in animal ecololgy is which environmental factors determine how animals move in nature. Many studies have examined animal locomotion under standardized laboratory conditions, but few have examined animal movement in nature, or have addressed which factors influence it. In both tropical and desert environments, we have examined how locomotion in lizards is influenced by many different environmental variables, such as the incline of hills (see below), perch diameter and height, and many other variables. Another question that is vitally important is what percentage of their maximum capacities do animals use in nature? Do animals always run at 100% of their capacities, or at only a small fraction of their abilities? Using video technology and tracking of footprints in the sand, we have been able to reconstruct in great detail the movements of these animals, and also determine which variables influence how fast they move, and what kind of locomotion they use. Together, this approach is a powerful and novel method that enables us to clearly understand the impacts of the environment on animal movement.
Irschick DJ, Losos JB. 1998. A comparative analysis of the ecological significance of locomotor performance in Caribbean Anolis lizards. Evolution 52:219-226
Irschick DJ, Jayne BC. 1999. A field study of effects of incline on the escape locomotion of a bipedal lizard, Callisaurus draconoides Physiological and Biochemical Zoology. 72:44-56
Jayne BC, Irschick DJ. 2000. A field study of incline use and preferred speeds for the locomotion of lizards. Ecology. 81:2969-2983.
Irschick DJ. 2000. Comparative and behavioral analyses of preferred speed: Anolis lizards as a model system. Physiological and Biochemical Zoology. 73:428-437
Irschick DJ. 2000. Effects of behavior and ontogeny on the locomotor performance of a West Indian lizard Anolis lineatopus. Functional Ecology. 14:438-444.
Irschick DJ, Garland T. Jr. 2001. Integrating function and ecology in studies of adaptation: Studies of locomotor capacity as a model system. Annual Review of Ecology and Systematics. 32:367-396.
DJ, Herrel A, VanHooydonck
B, Huyghe K, Van Damme R. 2005. Locomotor compensation creates a mismatch between laboratory and field
estimates of escape speed in lizards: A cautionary tale for performance to
fitness studies. Evolution
McElroy E, Meyers JJ, Reilly SM, Irschick DJ. 2007. Dissecting the effects of behavior and habitat on the locomotion of a lizard (Urosaurus ornatus). Animal Behaviour. 73:359-365.
Hammerschlag, N, Luo J, Irschick DJ, Ault JS. 2012 A comparison of spatial and movement patterns between sympatric predators: Bull sharks (Carcharhinus leucas) and Atlantic Tarpon (Megalops atlanticus). PLOS ONE. 10.1371/journal.pone.0045958.
Gilman C, Irschick DJ. 2012. Foils of flexion: the effects of perch compliance on lizard locomotion and perch choice in the wild. Functional Ecology. In press.