Comparative Ecology and Demography of Two Populations of Australian Reptiles (Lacertilia, Scincidae)

Abstract

The ecology and demography of 'Lampropholis guichenoti' and 'Hemiergis decresiensis' was studied at Newholme, Armidale, N.S.W. from 1981 to 1984. The study was carried out in spring, summer, autumn and to a limited extent over winter. The study looked at reproductive patterns of skinks of tropical versus temperate distribution, partitioning of activity time, food, habitat and temperature requirements. It emphasized similarity and differences in use of environmental resources by the two species. The other aspect that was dealt with in detail was morphology.The approach was to examine the adaptive and functional nature of body size, body shape, tail loss and individual growth. Body size was found to be influenced most by the environmental parameter, rainfall. Body shape was related to microhabitat use and 'H. decresiensis' that tended to 'swim' through litter and use small holes in trees was found to be more streamlined than 'L. guichenoti'. Tail loss was found to occur more frequently among larger (hence older) individuals. Individual growth was found to relate to age. Young grew faster than older conspecifics. Females of both species showed greater reproductive activity over spring and summer. By autumn,hatchlings or newborn of each species had appeared and were awaiting their first brumation. The young spent most of their time after birth or hatching eating and together with all other age/size groups built up body fat in autumn before the advent of winter. The female reproductive cycle in both species was found to be closely related to temperature and rainfall.