Interspecific aggression and habitat partitioning in garter snakes.
Defense of a limited resource, such as space or food, has recently been discovered in snakes and has been widely documented in lizards. Garter snakes (Thamnophis spp.) are historically considered generalist predators such that food is not a limiting resource. However, in this study we show that the common garter snake (Thamnophis sirtalis) and the aquatic garter snake (Thamnophis atratus) show a strong preference for amphibians as their primary food source at the Santa Lucia Preserve (SLP), Monterey County, California. This food preference forces these snake species at SLP to exploit aquatic habitats. Our principle goal was to investigate the aggressive behavior of T. sirtalis and the potential that this aggression displaces T. atratus from its preferred habitat. We found that when individuals from either species are alone, a 100% preference for aquatic or near aquatic habitat is observed. In contrast, when these species are together, T. sirtalis occupy the aquatic habitat and T. atratus occupy an area far removed from water. Thamnophis sirtalis often physically force T. atratus from the aquatic habitat through repeated biting and other displays of aggression.
Department of Natural Science and Mathematics, Lewis-Clark State College, Lewiston, Idaho, United States of America.
Michael
M
Edgehouse
Department of Biology, Reed College, Portland, Oregon, United States of America.
Leigh C
LC
Latta
Department of Biology and Mountain Lake Biological Station, University of Virginia, Charlottesville, Virginia, United States of America.
Edmund D
ED
Brodie
Department of Biology, Utah State University, Logan, Utah, United States of America.
Edmund D
ED
Brodie
D000374:Aggression; D000818:Animals; D001522:Behavior, Animal; D017812:Colubridae / Q000502:physiology*; D017753:Ecosystem; D005247:Feeding Behavior; D005260:Female; D008297:Male