Kelly M. Hare

Size, Growth, and Survival Are Reduced at Cool Incubation Temperatures in the Temperate Lizard Oligosoma suteri (Lacertilia: Scincidae)

Abstract Reptile eggs from cool temperate environments often experience cool incubation conditions, which may have long-term consequences for individual fitness. We studied the effects of artificial incubation regimes on size, growth, and survival of New Zealands only endemic oviparous lizard, Oligosoma suteri. Eggs were randomly distributed among three incubation temperatures (18, 22, 26 C) and two water potentials (−120 and −270 kPa). Hatchlings incubated at 22 C and −120 kPa were significantly larger for most measurements than hatchlings from other incubation treatments. Juveniles from the two higher incubation temperatures had more rapid growth and ultimately greater size by 12 months, as well as significantly higher survival to 18 months, than did 18 C incubated individuals. Hatchling size did not influence survival. Our data suggest that the restricted northern distribution of O. suteri results from ecological constraints caused by the negative effects of cool incubation temperatures on embryos and subsequently hatchlings.

Incubation regime affects juvenile morphology and hatching success, but not sex, of the oviparous lizard Oligosoma suteri (Lacertilia: Scincidae)

Abstract We studied the effects of different artificial incubation regimes on the hatching success, morphology, and sex of hatchlings of New Zealands only endemic egg‐laying skink, Oligosoma suteri (Boulenger, 1906). Eggs were randomly distributed among three constant incubation temperatures (18, 22, and 26°C) and two water potentials (‐120 and ‐270 kPa). Hatching success and hatchling survival were greatest at 22 and 26°C. Hatchlings from 18°C incubation had low survival, morphological abnormalities of the limbs, and atypical colouration. Water potential did not influence hatchling survival, morphology, or sex. Equal sex ratios were found at all incubation regimes indicating that sex determination in O. suteri is genetic, not temperature‐dependent.

Daily Patterns of Metabolic Rate among New Zealand Lizards (Reptilia: Lacertilia: Diplodactylidae and Scincidae)

In addition to the effects of temperature fluctuations on metabolic rate, entrained endogenous rhythms in metabolism, which are independent of temperature fluctuations, may be important in overall energy metabolism in ectotherms. Daily entrained endogenous rhythms may serve as energy‐conserving mechanisms during an animal’s active or inactive phase. However, because nocturnal lizards often take advantage of thermal opportunities during the photophase (light), their daily metabolic rhythms may be less pronounced than those of diurnal species. We measured the rate of oxygen consumption (V̇o2) as an index of metabolic rate of eight temperate lizard species (four nocturnal, three diurnal, and one crepuscular/diurnal; n = 7–14) over 24 h at 13°C and in constant darkness to test whether daily patterns (including amplitude, magnitude, and time of peak V̇o2) of metabolic rate in lizards differ with activity period. We also tested for phylogenetic differences in metabolic rate between skinks and geckos. Three daily patterns were evident: 24‐h cycle, 12‐h cycle, or no daily cycle. The skink Cyclodina aenea has a 12‐h crepuscular pattern of oxygen consumption. In four other species, V̇o2 increased with, or in anticipation of, the active part of the day, but three species had rhythms offset from their active phase. Although not correlated with activity period or phylogeny, amplitude of V̇o2 may be correlated with whether a species is temperate or tropical. In conclusion, the metabolic rate of many species does not always correlate with the recorded activity period. The dichotomy of ecology and physiology may be clarified by more in‐depth studies of species behaviors and activity periods.

Online trading tools as a method of estimating propagule pressure via the pet-release pathway

The increasing amount of internet trade in live animals has facilitated the sale and circulation of exotic species all over the world. This is an area of concern, as the deliberate or accidental release of pets is an important pathway by which exotic species are often introduced into new environments, often with negative effects on the local species and ecosystems. Internet trading sites were used to determine the distribution and magnitude of propagule pressure of red-eared slider turtles (RES; Trachemys scripta elegans) within the New Zealand pet trade. Sites were tracked daily from October 1, 2007 to September 30, 2009 and information on age, sex, season, and location was recorded. More than 1,500 sales and 80 reports of lost/found RES were recorded. Unsurprisingly, the highest number of sales and lost/found RES was in Auckland, the region with the highest human population. Females were more often reported as lost or found than males, despite a similar sex ratio of sales. The type and quality of information gathered in this manner is not perfect, as it only provides an estimate of minimum numbers of animals that are being traded/lost into the environment, but nonetheless, provides useful data when planning a management or eradication plan for feral turtles in New Zealand. Of concern, our results highlighted areas where turtles were most often being released in New Zealand, being those areas predicted to be the most climatically-suitable for this species, and in which incubation conditions were most likely to be met. Monitoring online sales of exotic species provides useful demographic information, as well as an indication of propagule pressure via the pet-release pathway. This technique is applicable to other species and may be a useful tool to help determine locations at risk of the establishment of other exotic species.

Low Incubation Temperatures Negatively Influence Locomotor Performance and Behavior of the Nocturnal Lizard Oligosoma suteri (Lacertidae: Scincidae)

Abstract We investigated the effects of artificial incubation regimes, experimental temperature, and age on the locomotor performance of New Zealands only endemic oviparous lizard, Oligosoma suteri. Artificial incubation is often used to produce founders of new populations of endangered reptiles and can have significant effect on juvenile phenotype. Eggs of O. suteri were randomly distributed among three incubation temperatures (18, 22, 26°C). Juvenile (n  =  117) maximum sprint speed was measured over three trials at 18, 22, and 26°C, and at one and four months of age, and behaviors during sprinting trials recorded. Sprint speed increased with an increase in experimental temperature and age. After removing the effect of individual size, juveniles incubated at low temperatures (18°C) were slower and exhibited locomotor behaviors likely to be detrimental for their survival (running towards stimulus). Individuals were consistently fast (or slow) at any given age or experimental temperature. Our data suggest that O. suteri incubated at warmer temperatures may have higher survival when released to the wild.

Low cost of locomotion in lizards that are active at low temperatures.

The nocturnality hypothesis of K. Autumn and coworkers states that nocturnal geckos have evolved a low energetic cost of locomotion (Cmin). A low Cmin increases maximum aerobic speed and partially offsets the decrease in maximum oxygen consumption caused by activity at low nocturnal temperatures. We tested whether a low Cmin is unique to nocturnal geckos or represents a more general pattern of convergent evolution among lizards that enables nocturnality and/or cold‐temperature activity. We measured Cmin in four carefully selected lizard species from New Zealand (two nocturnal and two diurnal; \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

Reproduction and Life History of New Zealand Lizards

n=5{\mbox{--}} 9

Frequency of tail loss does not reflect innate predisposition in temperate New Zealand lizards

\end{document} individuals per species), including a nocturnal and diurnal gecko (a low Cmin is a gecko trait and is not related to nocturnality), a nocturnal skink (a low Cmin is related to being nocturnal), and a diurnal skink active at low temperatures (a low Cmin is related to being active at low body temperatures). The Cmin values of the four species measured in this study ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape