Integrating physiology into conservation: an approach to help guide translocations of a rare reptile in a warming environment

Abstract

The physiology of an animal determines the range of environmental conditions under which it can survive. Surprisingly, relatively few conservation studies have used physiology to make predictions about the performances of translocated individuals in their new environment. Tuatara Sphenodon punctatus are of international significance as the last rhynchocephalian reptile. Natural populations are now restricted to $30 offshore islands in northern New Zealand, where survival of at least one population is threatened by climate change. Translocation to cooler regions (further south, but within the past latitudinal range of the genus) is an important option for future management. However, the genetic suitability of available source populations for environments that are currently cooler is unclear. To help predict the success of translocation, we examined the effects of cool temperature on juveniles sourced from one of the most southerly natural populations and compared these with three lizard species that inhabit southern New Zealand. We found that tuatara possess the same range of preferred body temperature, feeding responses to cool temperatures and critical thermal minimum as these three lizard species. However, tuatara did not digest at temperatures below 12 1C, suggesting that new reintroduction sites must offer enough basking opportunities to allow digestion of prey in winter. As tuatara showed responses to cold temperatures similar to lizards from southern New Zealand, we predict that tuatara will survive if translocated south of their current range, but whether they will be able to produce self-sustaining populations still needs investigation. Physiological predictions from the current study should now be combined with measurements of population performance in an experimental translocation.

Investigating Kleptothermy: A Reptile-Seabird Association with Thermal Benefits

“…The tuatara preferred body temperature is in the range 19.5°-23.rC (Besson and Cree 2011), but recordings of ambient temperatures in our study indicated that this preferred body temperature could be achieved within the shaded forest in only one of the three years studied. Fairy prions enable tuatara to maintain a higher body temperature through the night for several months of the year, October to January (austral spring to summer).…”

Are viviparous lizards from cool climates ever exclusively nocturnal? Evidence for extensive basking in a New Zealand gecko

“…In species of Woodworthia and other geckos, and regardless of sex, increased T b has many physiological benefits including increased growth rate (Autumn & De Nardo, ; Angilletta, ), faster prey capture, handling and digestion (Besson & Cree, ) and faster sprint speed (Gaby et al ., ). In lizards generally, basking may also facilitate fast re‐growth of the tail after autotomy – a considerable advantage as tail loss is detrimental both socially and physiologically (Fox & Rostker, ; Bateman & Fleming, ).…”

Geographic variation in the Pine Barrens Treefrog (Hyla andersonii): concordance of genetic, morphometric and acoustic signal data

“…In the conservation context, if the focal populations are not exchangeable, numerical enhancement or translocations of individuals across sites can be counterproductive (Hey et al . ; Besson & Cree ) or opportunities for genetic rescue can be overlooked (Beauclerc et al . ; Huff et al .…”

“…Most obviously, species delimitation can be inaccurate and lead to misleading phylogenetic hypotheses or mistaken assessments of the importance of particular supposed isolating mechanisms (Bickford et al 2007;Rittmeyer & Austin 2012). In the conservation context, if the focal populations are not exchangeable, numerical enhancement or translocations of individuals across sites can be counterproductive (Hey et al 2005;Besson & Cree 2011) or opportunities for genetic rescue can be overlooked (Beauclerc et al 2009;Huff et al 2011).…”