Parturient behaviour of a viviparous skink: evidence for maternal cannibalism when basking opportunity is low

<p>We documented the behaviour of pregnant McCann’s skinks (<i>Oligosoma maccanni</i>) before, during and after parturition. Females were maintained in captivity from early pregnancy under thermal environments differing in basking opportunity (low, mid and high regimes). Thermal regime during pregnancy had little influence on maternal behaviours, including basking behaviour prior to birth and the duration of, and site selection for, labour. The majority of births (78%) occurred in the open and warm areas. Most females (61%; <i>n</i> = 102 births, <i>n </i>= 36 females) aided offspring post-birth by biting them free of the enclosing extra-embryonic membrane. Some females from the low regime consumed non-viable offspring, but whether this is a consistent difference among females held under different basking regimes requires further study. Many females (c. 79%) also exhibited a brief transient decrease in control of hind-limbs post-birth. Further studies on other squamates are recommended to shed light on the evolutionary history and possible conservation consequences of maternal behaviour during parturition.</p

Nest-site selection and the factors influencing hatching success and offspring phenotype in a nocturnal skink. Supplementary Figures

<p>Nest-site selection in ectothermic animals influences hatching success and offspring phenotype, and it is predicted that females should choose nesting sites that maximise their reproductive fitness, ultimately through the reproductive success of their offspring. We completed nest-site choice experiments on a nocturnal lizard, the egg-laying skink (<i>Oligosoma suteri</i>), to determine whether eggs (and subsequent hatchlings) from cooler nests do better at cooler incubation temperatures, and conversely if those laid in warmer nests perform better at warmer incubation temperatures. We provided a simple nest-choice experiment, with oviposition-retreat sites available in either a hot or a cool sector of the enclosure; in the wild females nest under objects. Female <i>O. suteri </i>laid eggs both during the day and night, and nested more in the hot than cool sector. Eggs from each clutch were split across three egg incubation temperatures (18°C, 22°C, 26°C) to decouple the impact of initial nest-site choice from the subsequent incubation temperature regime. Whether eggs were initially laid in the hot or cool sector was not related to hatching success, offspring phenotype or offspring locomotor performance. We conclude that offspring phenotype and performance is primarily influenced by the temperature during incubation, rather than the initial thermal environment of the nest location. Thus, female <i>O. suteri </i>may select warmer nesting sites to ensure higher incubation temperature and enhanced offspring fitness.</p