I studied the common musk turtle (Sternotherus odoratus) at the northern limit of its range at Norway Bay, Quebec, from April to October 2006. Common musk turtles are habitat specialists and are selective of their habitats at the study-area and home-range scales. Beaver ( Castor canadensis) lodges were preferred at the study-area scale. Common musk turtles also preferred beaver lodges, emergent wetlands, aquatic beds with floating and submerged vegetation as well as rocky shores at the home-range scale. At the location scale, common musk turtles chose shallower and cooler sites that contained more logs and submerged vegetation than the sites available at random. There was no significant effect of sex on habitat use at the location scale. There was no significant difference in mean daily movements between the sexes during the active season. However, sex and month probably interact together to influence the mean distance traveled daily by common musk turtles in Norway Bay. Males appeared to move more than females in May, July, and October. Females appeared to move more daily than males in August and September. Neither sex appeared to move more daily in June. However, our small sample size did not allow us to conduct a conclusive analysis. The mean home-range area was 23.9 ha and was not different between sexes. I estimated a density of 4.1 turtles/ha and a sex ratio of 1.7M: 1F. The population includes 59.6% males, 35.8% females, and 4.6% juveniles. Adults ranged from 77 mm to 133 mm in carapace length.

No description available.

An ecological study was undertaken on four populations of Krefft�s River Turtle Emydura krefftii inhabiting the Townsville Area of Tropical North Queensland. Two sites were located in the Ross River, which runs through the urban areas of Townsville, and two sites were in rural areas at Alligator Creek and Stuart Creek (known as the Townsville Creeks). Earlier studies of the populations in Ross River had determined that the turtles existed at an exceptionally high density, that is, they were superabundant, and so the Townsville Creek sites were chosen as low abundance sites for comparison. The first aim of this study was to determine if there had been any demographic consequences caused by the abundance of turtle populations of the Ross River. Secondly, the project aimed to determine if the impoundments in the Ross River had affected the freshwater turtle fauna. Specifically this study aimed to determine if there were any difference between the growth, size at maturity, sexual dimorphism, size distribution, and diet of Emydura krefftii inhabiting two very different populations. A mark-recapture program estimated the turtle population sizes at between 490 and 5350 turtles per hectare. Most populations exhibited a predominant female sex-bias over the sampling period. Growth rates were rapid in juveniles but slowed once sexual maturity was attained; in males, growth basically stopped at maturity, but in females, growth continued post-maturity, although at a slower rate. Sexual maturity was at 6-7 years of age for males, which corresponded to a carapace length of 150-160 mm, and 8-10 years of age for females, which corresponded to a carapace length of 185-240 mm. The turtles were omnivorous, although in the Ross River they ate more submerged vegetation (by percent amount and occurrence) than those of the Townsville Creeks. Turtles in Townsville Creeks ingested more windfall fruit and terrestrial insects.

Causes of morbidity and mortality were investigated for 108 green turtles (Chelonia mydas) stranded in south-east Queensland between 1990 and 1996. This study was undertaken as part of a broader carcass salvage program for south Queensland, and within the context of a population study of C. mydas in the Moreton Bay feeding ground. Accurate pathological characterisation of disease in C. mydas was achieved by detailed necropsy and histological examination. Varied inflammatory responses and degenerative changes were observed in stranded C. mydas. Supportive disciplines of microbiology, parasitology, and clinical chemistry were used to elucidate aetiology and pathogenesis of selected conditions. Heavy metal and pesticide levels were assessed in a sub-sample of turtles. Direct anthropogenic causes (including trauma, foreign body ingestion and drowning) accounted for 34% of mortalities of C. mydas in this study. The majority of the trauma cases were turtles with skull fractures resulting from blunt impacts. The remainder had boat propeller injuries, or miscellaneous trauma. Almost half of the turtles with lethal boat propeller damage had evidence of pre-existing disease which may well have predisposed them to boat strike, emphasising the importance of full necropsy examination, even when the cause of death appears obvious. Fishing line was the only ingested foreign body consistently implicated in the production of fatal intestinal obstruction. Marine turtle fibropapillomatosis, a panzootic viral disease which is considered to involve some indirect anthropogenic factors, accounted for 7% of mortalities. The findings in this study were consistent with much of the previously described pathology of this condition. Naturally-occurring diseases (for which human influences are unknown) accounted for the remaining 59% of strandings. Coccidiosis, caused by Caryospora cheloniae, was recorded for the first time in wild C. mydas. It occurred both as an epizootic (in 1991) and as sporadic cases. A variety of manifestations, including disseminated and enteric forms, were recognised. Infection with a Cryptosporidium-like protozoan appeared to occur concurrently with coccidiosis in one turtle in this study. Attempts to establish experimental coccidial infections in hatchling C. mydas were unsuccessful. Infections with cardiovascular (spirorchid) flukes were almost universal in stranded C. mydas in this study. They ranged from mild, incidental findings (such as occasional fluke vii egg granulomas evident microscopically in otherwise normal tissues) to a variety of severe changes, including thrombosis, which were likely to have produced morbidity. The present study clarified the range of cardiovascular lesions associated with spirorchidiasis, including the sequence of thrombus resolution and exteriorisation from vessels. In some cases spirorchid vasculitis was associated with fatal disseminated bacterial infections. Other sporadic, naturally-occurring diseases included mycotic pneumonia, bacterial meningoencephalitis and a miscellany of gastrointestinal conditions, including chronic intestinal tympany and obstipation, for which the underlying cause could not always be determined. Evidence indicated that gastrointestinal motility in C. mydas was prone to both direct and indirect disturbance and that tympany and obstipation could be final common outcomes of a range of insults. Eighteen abnormally buoyant turtles were examined during this study. The cause could usually be ascribed to an underlying disease, including (in decreasing order of frequency) trapped internal gas, usually intestinal; neurological disease such as traumatic brain injuries; and pulmonary disease. In two cases, no underlying cause was detected. Trace metal (arsenic, cadmium, mercury, selenium and zinc) concentrations were determined in the livers and kidneys of 50 turtles of mixed species (mostly C. mydas). These results were considered to provide baseline data for sea turtles in SE Qld. This study offered the largest dataset available for some metals in C. mydas, and provided evidence of high background levels of cadmium as a normal feature for the species. Some unusual age–related trends in metal accumulation were detected. Concentrations of cadmium, zinc and selenium in the kidney decreased with increasing age, whereas zinc concentrations in the liver tended to increase. Determining the impact of disease on wildlife populations is an increasingly necessary task, which will require multidisciplinary teams. Necropsy surveys like the present study are an essential component of the growing field of conservation medicine. In addition to providing data relevant to management, such as the relative proportions of anthropogenic and naturally-occurring mortalities, necropsy surveys can identify a range of endemic pathogens, and help to collect prevalence data for determining disease impacts at the population level.