Edgehouse Michael, Latta Leigh C, Brodie Edmund D, Brodie Edmund D
Department of Natural Science and Mathematics, Lewis-Clark State College, Lewiston, Idaho, United States of America.
Department of Biology, Reed College, Portland, Oregon, United States of America.
PLoS One. 2014 Jan 22;9(1):e86208. doi: 10.1371/journal.pone.0086208. eCollection 2014.
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.
最近在蛇类中发现了对有限资源（如空间或食物）的防御行为，并且在蜥蜴中也有广泛记载。束带蛇（美洲束带蛇属）在历史上被认为是广食性捕食者，因此食物不是限制资源。然而，在本研究中我们发现，普通束带蛇（西部束带蛇）和水生束带蛇在加利福尼亚州蒙特雷县的圣卢西亚保护区（SLP）表现出强烈偏好将两栖动物作为其主要食物来源。这种食物偏好迫使SLP的这些蛇类物种去利用水生栖息地。我们的主要目标是研究西部束带蛇的攻击行为以及这种攻击行为将水生束带蛇从其偏好栖息地赶走的可能性。我们发现，当任一物种的个体单独存在时，会观察到它们100%偏好水生或近水生栖息地。相比之下，当这些物种在一起时，西部束带蛇占据水生栖息地，而水生束带蛇则占据远离水域的区域。西部束带蛇经常通过反复撕咬和其他攻击行为将水生束带蛇从水生栖息地赶走。
