Meeting Abstract
90.6 Thursday, Jan. 7 Skull development, functional integration and feeding performance in a top North American carnivore, Canis latrans LA CROIX, S.*; ZELDITCH, M.L.; SHIVIK, J.A.; LUNDRIGAN, B.L.; HOLEKAMP, K.E.; Michigan State Univ., East Lansing; Univ. of Michigan, Ann Arbor; USDA Wildlife Services National Wildlife Research Center & Utah State University, Logan; Michigan State Univ., East Lansing; Michigan State Univ., East Lansing lacroixs@msu.edu
The coordination of form and function is of particular interest during ontogeny, when developing animals must resolve the conflicting demands of growth and survival. Infant mammals do not directly compete with adults for food but must be competent to do so after weaning. During post-natal development, skull size and shape undergo tremendous changes across steep growth trajectories and must remain functional throughout that transition. Using an ontogenetic series of known-age coyote skulls, we address questions of form and of function concurrently. We find that, at birth, the shape of the coyote cranium is much less mature than the mandible. Both cranium and mandible exhibit significant changes in their ontogenetic allometries between pre- and postweaning life history stages as well as between postweaning and juvenile stages. Both cranium and mandible continue to grow and change shape past 20 wks of age, long after weaning at 6 wks of age. Cranial and mandibular shape are significantly correlated during the preweaning, postweaning and juvenile life history stages, a covariance that cannot be explained solely by age- or size-related allometry. Feeding performance improves beyond morphological maturation, with bite-force of adults exceeding that of subadults. Our results show that skull size and shape continue development after weaning, with feeding performance improving even after skull size and shape mature. That ongoing improvement in feeding function suggests an integration of the cranium and mandible beyond their individual size and shape allometries.
