Dr. Brian Walker

Research in Animal Physiology

I am interested in how animals adapt - physiologically - to different environments. Specifically, I focus on how anthropogenic (aka human) disturbances affect the stress physiology of free-living birds and mammals. I spend most of my energy on examining hormone changes in these free living beasts - a rather new discipline called "environmental endocrinology." While behavioral consequences of human perturbations are well documented in ecological studies - less attention focuses on the internal physiological changes that animals must make in order to successfully adapt to disturbed environments (or fail to make and thus do not adapt). Physiological consequences of disturbances are important, for patterns of behavior responses do not always exemplify internal changes in homeostasis. Thus, while certain species may outwardly "appear" to do well in human-disturbed locations, might there be internal affects - which are much more difficult to measure - that could be affecting their lives. These "masked" physiological effects might be particularly pertinent, as there is mounting support for the idea that physiological costs of current disturbances may not be manifest until much later is life.

The urban landscape surrounding Fairfield will be an excellent laboratory for the examination of human-wildlife interactions. My lab will initially focus on avian species (i.e., local passerines, and perhaps the feral monk parakeets - Myiopsitta monachus and the "wild" turkeys - Meleagris gallopavo - that patrol the Fairfield campus). Expansion to include resident mammal populations would also be exciting. In addition to this local work, I will continue working with penguins (the focus of my PhD dissertation) in collaboration with SeaWorld, in San Diego, CA. This work will likely focus on the effects of captive breeding on the development of the physiological stress response in a number of penguin species.

Courses Taught

• BI 76 Environmental Science
• BI 172 General Biology (Majors)
• BI 313 Comparative Physiology

Publications

Walker, BG, PD Boersma, and JC Wingfield. 2006. Habituation of adult Magellanic penguins to human visitation as expressed through behavior and corticosterone secretion. Conservation Biology 20:146-154.

Walker, BG, PD Boersma, and JC Wingfield. 2005. Physiological and behavioral differences in Magellanic penguin chicks in undisturbed and tourist-visited locations of a colony. Conservation Biology 19:1571-1577.

Walker, BG, PD Boersma, and JC Wingfield. 2005. Field Endocrinology and Conservation Biology. Integrative and Comparative Biology 45:12-18.

Walker, BG, JC Wingfield, and PD Boersma. 2005. Age and food deprivation affect expression of the glucocorticosteriod stress response in Magellanic penguin (Spheniscus magellanicus) chicks. Physiological and Biochemical Zoology 78:78-89.

Lynn, SE, BG Walker, and JC Wingfield. 2005. A phylogenetically controlled test of hypotheses for behavioral insensitivity to testosterone in birds. Hormones and Behavior 47:170-177.

Walker, BG, PD Boersma, and JC Wingfield. 2004. Physiological condition in Magellanic Penguins: Does it matter if you have to walk a long way to your nest? Condor 106:696-701.

Moore, IT, BG Walker, and JC Wingfield. 2004. The effects of combined aromatase inhibitor and anti-androgen on male territorial aggression in a tropical population of rufous-collared sparrows, Zonotrichia capensis. General and Comparative Endocrinology 135:223-229.

Walker, BG, and PD Boersma. 2003. Diving behavior of Magellanic penguins (Spheniscus magellanicus) at Punta Tombo, Argentina. Canadian Journal of Zoology 81:1471-1483.

Boveng, PL, BG Walker, and JL Bengtson. 1996. Variability in Antarctic fur seal dive data: Implications for TDR studies. Marine Mammal Science 12:543-554.

Walker, BG, and PL Boveng. 1995. Behavioral effects of time-depth recorders on lactating Antarctic fur seals. Canadian Journal of Zoology 73: 1538-1544.

Bengtson, JL, PL Boveng, L Hiruki, JK Jansen, WR Meyer, MK Schwartz, and BG Walker. 1994. Antarctic Marine Living Resources program: pinniped and seabird studies at Seal Island, South Shetland Islands, during the 1993-1994 austral summer. Antarctic Journal of the United States 29:200-201.

Walker, BG, and WD Bowen. 1993. Behavioural differences among adult male harbour seals during the breeding season may provide evidence of reproductive strategies. Canadian Journal of Zoology 71:1585-1591.

Walker, BG, and WD Bowen. 1993. Changes in body mass and feeding behaviour in male harbour seals, Phoca vitulina, in relation to female reproductive status. Journal of Zoology, London 231:423-436.

Bengtson, JL., JK Jansen, WR Meyer, RV Miller, MK Schwartz, and BG Walker. 1993. AMLR program: fur seal and seabird studies at Seal Island, South Shetland Islands, during the 1992-1993 austral summer. Antarctic Journal of the United States 27:200-201.