Recruitment in tuatara
- School of Biological Sciences, Victoria University, Wellington
Some appreciation of recruitment processes in tuatara, Sphenodon punctatus (Reptilia:Rhynchocephalia) and the habitat requirements of small juveniles is essential to the long-term management of surviving natural populations. It is also important that this information be acquired while a large and relatively secure breeding population, such as the one on Stephens Island, still exists.
A survey of juvenile habitats and dispersion on Stephens Island in the summer of 1987-88 has provided input to DOC plans for revegetating the island, and a framework for the census of juveniles
Tracking data combined with population counts and meteorological records, provide guidelines for management of the habitat, and appropriate timing and methods for census. Information on clutch sizes and egg mortality, (MEM & Dr M. Thompson, VUW) in conjunction with new understanding of female reproductive cycles (Dr A. Cree, VUW), and of habitat quality in relation to population densities (Dr J. Gillingham, CMU), provides a basis to estimate annual production and compare this with field data. A modelling approach is necessary to estimate survival beyond 4-S months when the hatchlings start to burrow, since part of the population (depending on time of year and weather) then becomes "hidden" underground.