Active travel to work in New South Wales 2005-2010, individual characteristics and association with body mass index

A population of eastern pygmy-possums (Cercartetus nanus) was studied in northern New South Wales for almost 3 years. A total of 98 pygmy-possums was captured, of which 52 were captured only once. The sex ratio of the population did not differ significantly from parity. Mid-way through the study, 1.4 ha of the 4.0-ha study site was cleared. Pre-clearing capture rates in nest boxes averaged 33.5 ± 5.8 captures per 100 box checks per month, and the population was estimated by three methods to be at least 15–20 animals. There was no significant difference in body mass between adult males (23.7 ± 6.3 g) and adult females (27.1 ± 7.7 g). Males had significantly larger short-term home ranges (0.35 ± 0.14 ha) than females (0.14 ± 0.06 ha) and tended to move over greater distances each night. Breeding occurred from summer to early winter, and juveniles and sub-adults entered the population in autumn and winter. The mean number of pouch young was 3.9. The most likely minimum size at which juveniles left their mother was 9–11 g. Adult body mass and condition were highly variable over time, and did not appear to be related to either the breeding season or Banksia flowering. Fourteen pygmy-possums were found torpid during the study. Population troughs occurred in late winter and spring and were associated with low survival and/or seasonal migration, possibly linked to the cessation of Banksia flowering in July and the lack of alternative food sources at this time and/or increased use of nest boxes by Antechinus stuartii during late winter. Post-clearing, capture rates fell to 7.8 ± 1.6 captures per 100 box checks per month, the estimated population size fell to 5–8 animals, and there was an almost total lack of juvenile/sub-adult recruitment into the population. The results support concerns that the long-term survival of the eastern pygmy-possum in New South Wales is threatened by continued land clearing throughout much of its present range.

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Morphological change and fat accumulation in juvenile red foxes (Vulpes vulpes) in the Central Tablelands of New South Wales

Wildlife Research ◽

10.1071/wr99072 ◽

2000 ◽

Vol 27 (5) ◽

pp. 525

Author(s):

Roy K. Winstanley

Keyword(s):

Body Mass ◽

Body Fat ◽

Vulpes Vulpes ◽

New South ◽

New South Wales ◽

First Year ◽

Male Body ◽

Energy Reserves ◽

Red Foxes ◽

South Wales

Juvenile red foxes (Vulpes vulpes) reach sexual maturation within 10 months of parturition. During this time juveniles need to manage their energy reserves to fuel maintenance metabolism, growth and reproduction. To determine juvenile growth rates and body energy reserves, I measured body mass, morphology, and estimated body fat, in free-living red foxes from approximately 8 weeks of age through to 1 year old. Foxes (n = 163) were sampled monthly from August 1995 to July 1996 in the Central Tablelands of New South Wales. Mean body mass of male and female juvenile foxes was indistinguishable from adult body mass by February, at 16 weeks of age (males 4500 g, females 4200 g). Skeletal measurements of body and forelimb length in both sexes also attained adult proportions by February. Further changes in morphology were minimal in first-year foxes. Total body fat was estimated indirectly using a kidney fat index. Estimated juvenile body fat remained low and stable (6%) in both sexes from December through March. Male body fat peaked in August (11%) but was low in July during mating and also September and October whilst females were denning. Estimated body fat of females peaked in August–September (13%) but declined sharply in October after parturition. In addition, 73% of first-year females sampled during August–October were either pregnant or had recently given birth.

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