This study summarizes 660 events involving captured, live-stranded and dead cetaceans in South Australia between 1881 and 2000. Emphasis is placed on records (n = 361) during 1985-2000 when an active necropsy programme was underway. Average number of events per year was 30.4 and the most common species were the short-beaked common dolphin (Delphinus delphis) and Indo-Pacific bottlenose dolphin (Tursiops aduncus). Records were assigned to nine categories of circumstance/cause of death. Summarizing the total database, 60% were unknown circumstance, 22% not obviously anthropogenic, 13% unintentional human-related and 5% intentional human-related. In the data set of records for 1985-2000, 50% were unknown, 25% were not obviously anthropogenic, 20% were unintentional humanrelated and 5% were intentional killings. Non-anthropogenic circumstances included neonatal deaths, live strandings, significant diseases, shark attacks and choking. Cornynebacterium ulcerans is recorded for the first time in a cetacean. Unintentional circumstances included entanglement in fishing and aquaculture equipment (17% of necropsied carcasses from 1985-2000) and boat strikes. Intentional human-related circumstances were captures for live display and illegal killing. Five percent of the necropsied carcasses during 1985-2000 were attributed to shootings or stabbings/spearings. There is need for a formal reporting procedure for marine mammal deaths and human interaction involving injury and for steps to be taken to reduce human impacts.
With 1 plate and 4 figures in the text) Breeding, population dynamics and seasonal changes in physical and physiological parameters were examined in the northern quoll (Dasyurus hallticatus) at Mitchell Plateau, Western Australia, between September 1981 and November 1982. Females gave birth to a single litter of young in July or August. Births were earlier on near-coastal sites than on inland sites. Litter size was greater on inland sites and litter size differed between years. By September all females were either carrying pouch young or were lactating. Lactation ceased by April. Testosterone levels in males peaked in July. There were significantly more male than female pouch young. However, in only one grid was the adult sex ratio different from parity, with an excess of females in September 1981 and 1982. Embryonic mortality was > 53% but loss of pouch young was small. Although males and females moved similar distances between successive recaptures, the extent of movement varied seasonally, being greatest in September. Males were generally larger and heavier than females. Seasonal variations were recorded for most physical and physiological parameters. The most pronounced changes occurred towards the end of the dry season (July to September) for both males and females. Over this period there was a significant decline in weight (males), haematocrit (males), plasma albumin (males) and leucocytes (both males and females) and significant elevations in values of haemoglobin and both free and protein-bound cortisol in both males and females. Few males survived the post-mating period from July to September. They appeared to decline in condition over this period more markedly than females: they lost more weight, their haematocrit and plasma albumin values declined to a greater extent, and they were more heavily infected with lice (Boopia uncinata). Males with lower testosterone and higher free and protein-bound cortisol had increased prospects of surviving the breeding season, which suggests that it is the dominant males that are less likely to survive the breeding season. Individuals in the three major populations at Mitchell Plateau differed greatly in their physiological values. The high-density population in a sandstone area had intermediate levels of free cortisol and higher haematocrit values than both the other populations, and higher levels of haemogl3bin than the population on laterite substratum.
Thirty species of rodents are recorded from South Australia. At the time of European settlement, the State probably supported at least 19 species of native rodents. Eight additional species have been recorded only in subfossil material. At least 11 species are now considered to be extinct and there have been significant declines in all the other species as a result of over 150 years of European influence. In addition, three species have been introduced to the State since European settlement. Over the last ten years, there has been a significant increase in our understanding of the distribution and ecology of what remains of the rodent fauna through a series of systematic, site-based biological surveys, a significant increase in research on subfossil and owl pellet remains, documentation of Aboriginal ecological knowledge and ecological and distributional studies on three species. This paper describes our current state of knowledge of the distribution, ecology and threats to the South Australian rodent fauna and makes suggestions for future research and conservation management.
This paper presents the background for a series on the biology of small mammals in the Mitchell Plateau region, an area characterised by a wet-dry tropical climate. From June 1981 to December 1982, 19 species of small terrestrial mammals were captured at Mitchell Plateau. Of 17 species captured on eight mark-release grids, 13 clustered into four significant groups which reflected the major habitats of the region: (1) Sminthopsis virginiae, Leggadina sp. and Pseudomys nanus in riparian and plateau escarpment sites; (2) Phascogale tapoatafa, Trichosurus arnhemensis and Pseudomys laborifex in plateau open forest; (3) Conilurus penicillatus and Mesembriomys macrurus in open woodland and coastal mosaics; (4) the commoner species Dasyurus hallucatus, Isoodon macrourus, Melomys sp. cf. burtoni, Zyzomys argurus and S. woodwardi in an array of habitats. Rattus tunneyi, Pseudantechinus sp., Wyulda squamicaudata and Planigale maculata did not cluster significantly with other species. Two species, Pseudomys delicatulus and Mesembriomys gouldii, were represented by single specimens captured outside the capture-mark-release grids, in sandstone and plateau woodland respectively. Open forests, particularly on the lateritic plateau surfaces, had the richest and most diverse mammal assemblage over the entire study period. The vine thickets and sandstone contained relatively stable populations of fewer species, and several habitats had seasonally variable populations and species.
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