Alterations in condition of cottontail rabbits (Sylvilagus floridanus) on rangelands following brush management.

Abstract

Although the use of herbicides and prescribed fire have been shown to increase density of cottontail rabbit (Sylvilagus floridanus) populations, the impact of such brush management practices on their condition has not been explored. We used discriminant analysis to investigate responses of overall physical condition of cottontail rabbits (n = 422 adults) to brush management and succession on replicated disturbed and undisturbed upland hardwood forest-tallgrass prairie over a 6-year period. Five different disturbed habitat types were experimentally created using herbicides (tebuthiuron or triclopyr), fire, or a combination of both. Parameters that were important discriminators of rabbit physical condition among habitat types and post-disturbance successional changes included indices of kidney fat and parasitism, and relative masses of spleen, liver, and dried stomach digesta. Brush management practices using herbicides influenced overall condition of rabbits, but the type of habitat disturbance was not important. Effects on overall body condition of cottontail rabbits from burning disturbed habitats were not apparent until later seral stages when production of herbaceous dicots declined and vegetative composition more closely resembled that of undisturbed areas.