8The pygmy bluetongue lizard, Tiliqua adelaidensis, is an endangered scincid lizard which occurs in 9 remnants of natural grasslands in the mid-north of South Australia. We assessed the factors affecting body 10 condition of male and female lizards, using body size residuals as an index, over five sampling years. We 11 included sex, phenotypic (patterned or plain morphs), temporal (sampling year and activity period within 12 year), and climatic factors in our analyses. The results indicated that sampling year and activity period 13 within the year were the two most important factors influencing variation in body condition of both male 14 and female lizards over the period of the study. There were similar trends when we considered females 15 separately in each of three stages of their reproductive cycle (pre-partum, gravid, post-partum). None of 16 the analyses showed any significant effect of phenotype on body condition. Winter-spring rainfall was 17 positively correlated with body condition of females in the pre-partum period, but showed no significant 18 effect on mean body condition of any other grouping of adult lizards, nor a consistent direction of 19 correlation among the different subsets of adult lizards that we considered. The substantial annual 20 variations in the body condition of lizards, although of uncertain cause, provide important information for 21 conservation managers who monitor persisting populations of this endangered species. 22 2
Abstract-There are applications for the measurement of body asymmetry as some studies have shown a correlation between asymmetry and fitness for some species. In our study of the endangered Pygmy Bluetongue Lizard, the asymmetry of its head is being investigated to see whether this has a correlation with its health and chance of survival in the wild. As there are restrictions on handling the endangered lizards, their digital photos must be taken in the field and therefore it is difficult to impose restrictions on the conditions under which the digital images are acquired. In this paper, we propose a novel automatic technique that is invariant to rotation, size, illumination and tilt, for the measurement of lizard symmetry based on its digital imagery and the resulting symmetry index is used to infer the lizard's asymmetry. The conventional manual methods being used by biologists for fluctuating asymmetry measurement have a number of disadvantages including human errors, and their methods of measurement are based on counting the number of scales and length measurement that do not often agree well with visual assessment. Our proposed image processing technique is non-invasive, robust in a way that will give a similar symmetric index for different images of the same lizard, and more importantly based on the actual image scale pattern of the lizards. Hence our proposed method will also give a better agreement with visual assessment.
9Phenotypic variation among offspring of individual animals is an important life-history trait. In 10 viviparous lizards, it could result from genetic variation of individuals and also differences in 11 environments experienced by mothers during gestation. We investigated variation in phenotype 12 and survival of neonate pygmy bluetongue lizards, Tiliqua adelaidensis, over three sampling 13 years. We explored changes in body condition, using body size residuals as an index, and body
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.