Meeting Abstract
33.2 Wednesday, Jan. 5 Variation in coyote skull morphology, biomechanics, and feeding behavior due to early bone processing opportunities LA CROIX, S.*; ZELDITCH, M.L.; SHIVIK, J.A.; LUNDRIGAN, B.L.; HOLEKAMP, K.E.; Michigan State Univ., E. Lansing; Univ. of Michigan, Ann Arbor; USDA/WS/National Wildlife Research Center and Utah State Univ., Logan; Michigan State Univ., E. Lansing; Michigan State Univ., E. Lansing lacroixs@msu.edu
Phenotypic plasticity, resulting from the sensitivity of developmental processes to environmental influences, enables ontogenies to produce multiple outcomes. We studied developmental plasticity in the morphology of the feeding apparatus and in feeding behavior with an experimental manipulation of diet in coyotes, a species at the highest trophic level of many North American ecosystems. Six-week old coyotes were assigned to two feeding groups, one with access to bones, and the other without. Subsequently, feeding performance trials were conducted at 18 months of age, followed by a geometric morphometrics analysis of the skulls. Animals with bone-processing opportunities during ontogeny had an adult skull shape that was significantly different from that of animals not afforded access to bones. Variation in morphology was specific to features associated with feeding performance – muscle attachment areas on the skull, biomechanical proportions, and mastication muscle mass. Animals with access to bones developed larger sagittal crests, broader zygomatic arches, broader upright arms of the coronoid, wider condylar and angular processes, and deeper horizontal rami. Further, early bone-processing opportunities improved adult feeding performance with faster consumption of dog biscuits and rawhide sticks, and greater reduction of shank bone mass. Thus, variation in early diet produced ontogenies leading to different outcomes for both adult form and function. This sensitivity of developmental processes to ecological variables, should, in turn, be expected to affect fitness.
