Neonatology of reptiles

Neonatal reptiles are here defined as an age class of young eureptilian amn iotes (excluding birds) that express attributes most influenced by the pre- paritive development environment (oviduct, egg, and egg nest) and by the de mands of parition and first dispersal. Neonatal character states are typica lly transformed, reduced, or eliminated during the first 10% of their prere productive development. Traditionally, neonates have not been distinguished from juvenile reptiles. As a result the neonatology of reptiles has rarely been addressed in past literature. Recent studies reveal a complex array o f developmental scenarios involving character state transformations, hetero chrony, unique character states in morphology, behavior, physiology, nutrit ion, dispersion and health. Unique morphological features (such as egg teet h) and limited skeletal ossification characterize many neonates. Distinguis hing behaviors include "reversal" movements, utilization of bright color pa tterns, and startling movements with both serving as anti-predation mechani sms. Prolonged association with protective parents, group migration, unique agonistic behavior, and tendencies toward rapid dispersion characterize th e neonates of individual species. Neonatal physiological attributes include : a special availability to inoculation by symbiont fermenting anaerobes in herbivores, rapid conforming responses to their external environments in t hermal and hydric exchanges, and in the case of some turtles, extraordinary capacities for supercooling (8.9 C). Post-paritive lecithotrophy (nutritio n from residual yolk) sustain both the ovenwintering of nestlings and the d ispersion of nonfeeding young for as long as several months. Resistance to infections (such as mycoplasmas) from their maternal parents,combine with n utritive reserves of residual yolk and a common tendency for rapid dispersi on to make neonates attractive candidates for augmentation and translocatio n programs. Coupled with the practical advantages of maintaining and manipu lating small animals in a laboratory environment, these qualities distingui sh neonates as particularly useful models for experimentally evaluating the relative apportionment of reproductive resources into greater numbers of o ffspring or into improved quality/survivorship of individual offspring.