title: The king of snakes: performance and morphology of intraguild predators (Lampropeltis) and their prey (Pantherophis).
abstract: Across ecosystems and trophic levels, predators are usually larger than their prey, and when trophic morphology converges, predators typically avoid predation on intraguild competitors unless the prey is notably smaller in size. However, a currently unexplained exception occurs in kingsnakes in the genusLampropeltisKingsnakes are able to capture, constrict and consume other snakes that are not only larger than themselves but that are also powerful constrictors (such as ratsnakes in the genusPantherophis). Their mechanisms of success as intraguild predators on other constrictors remain unknown. To begin addressing these mechanisms, we studied the scaling of muscle cross-sectional area, pulling force and constriction pressure across the ontogeny of six species of snakes (Lampropeltiscaliforniae,L.getula,L.holbrooki,Pantherophisalleghaniensis,P.guttatusandP.obsoletus). Muscle cross-sectional area is an indicator of potential force production, pulling force is an indicator of escape performance, and constriction pressure is a measure of prey-handling performance. Muscle cross-sectional area scaled similarly for all snakes, and there was no significant difference in maximum pulling force among species. However, kingsnakes exerted significantly higher pressures on their prey than ratsnakes. The similar escape performance among species indicates that kingsnakes win in predatory encounters because of their superior constriction performance, not because ratsnakes have inferior escape performance. The superior constriction performance by kingsnakes results from their consistent and distinctive coil posture and perhaps from additional aspects of muscle structure and function that need to be tested in future research.
authors.affiliation: Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70504-43602, USA davidapenning@gmail.com.|Department of Biology and Environmental Health, Missouri Southern State University, Joplin, MO 64801, USA.
authors.forename: David A
authors.identifier: 0000-0002-5368-9900
authors.initials: DA
authors.lastname: Penning
authors.affiliation: Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70504-43602, USA.
authors.forename: Brad R
authors.initials: BR
authors.lastname: Moon
mesh_terms: D000818:Animals; D049628:Body Size; D017812:Colubridae / Q000033:anatomy & histology* / Q000502:physiology*; D004924:Escape Reaction; D020387:Food Chain; D011235:Predatory Behavior
keywords: Constriction; Cross-sectional area; Force; Muscle; Pressure; Scaling