Key Findings
Male and female bobcats had different responses to the landscape, but in general a greater proportion of residential and agricultural land uses was associated with higher cortisol levels. Larger bobcats had lower cortisol levels. Cortisol in all bobcats was lower in the spring than in the fall. Finally, below-average temperatures in the fall related to lower cortisol levels.
About the Co-Author
Thomas Foxall, Professor of Biological Sciences
Contact information: Tom.Foxall@unh.edu
603-862-2354
This research first published in The Journal of Wildlife Management.
Researchers: R. Carroll, M. Litvaitis, and T. Foxall.
Using hair samples of bobcats (Lynx rufus), UNH scientists discovered that bobcats living closer to residential and agricultural areas have higher cortisol levels. All mammals – including humans – have a stress response where, when faced with difficult and threatening situations, the hormone cortisol is released. Increased cortisol in hair samples often is a marker of higher stress levels because the more of the hormone circulating in the bloodstream, the more that will end up in our hair.
Under normal conditions, cortisol helps regulate energy and provide the resources needed to deal with a stressful situation. However, chronically high cortisol levels can worsen individual bobcats’ health and lower reproduction rates of populations
According to the New Hampshire Fish and Game and UNH researchers, New Hampshire has approximately 1,400 bobcats. Small predators such as bobcats and coyotes now are the top “apex” predators in the region. As such, they have a large impact on the state's forest ecosystems, helping sustain balanced wildlife communities of smaller mammals such as rodents, rabbits, and groundhogs that can carry diseases and disrupt production on commercial farms and backyard gardens.
“Populations are always changing, and we want to understand what has caused some pretty dramatic rises and falls [in bobcat populations] over the decades,” described wildlife ecologist Rory Carroll '19G, a Ph.D. graduate from UNH. “They are currently pretty abundant across the region despite a huge human influence on the landscape. Knowledge on how they are learning to live alongside humans will ultimately help us be better and more responsible neighbors of our wildlife species and target conservation efforts in critical areas to sustain healthy populations.”
Knowledge on how [bobcats] are learning to live alongside humans will ultimately help us be better and more responsible neighbors of our wildlife species and target conservation efforts in critical areas to sustain healthy populations of bobcats.
This material is based upon work supported by the NH Agricultural Experiment Station, through joint funding of the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 1009906, and the state of New Hampshire. It also was supported by the National Science Foundation Graduate Research Fellowship, under award number 147766, and the Southern Arkansas University Foundation. New Hampshire Fish and Game, Vermont Fish and Wildlife, Squam Lake Natural Science Center, and the Buttonwood Park Zoo made vital contributions to sampling efforts for this study. Co-authors include R. Carroll, M. Litvaitis, and T. Foxall.
