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Diet of the rare yellow-footed rock wallaby (Petrogale xanthopus) was found by study of faeces along the escarpment of the Coturaundee Range in western New South Wales, Australia. Normally 42 to 52% of the diet (estimated as the occurrence of recognizable particles within a microscope field) was of forbs, mostly small herbaceous ephemeral species. During drought the most important component was browse, 44% of diet. Grass was important. There was considerable overlap of species eaten by the rock wallabies and the introduced goats and rabbits, 75% in the case of goats during drought; rabbits were not seen in the higher parts of the escarpment. There was less competition from the euros (Macropus robustus). Control of introduced herbivores may be essential if the rock wallaby populations are to have a chance of recovery.

Stomach contents of free-ranging animals were analysed botanically for low Atriplex shrubland in western New South Wales, Australia, during 1972-74 in good seasons producing abundant growth and diversity of vegetation. Red kangaroo (Megaleia rufa), euro (Macropus robustus) and sheep (Ovis aries) selected grass and forbs when those were readily available. In poorer pasture sheep selected mainly flat-leaved chenopods (saltbush) and kangaroos selected mainly grass with different amounts of flat- or round-leaved chenopods. Euros were the most selective, eating grass even when there was little grass present. Potential overlaps in diet between kangaroos and sheep were greatest in good pasture and least in the poorest conditions. The other groups of plants considered were non-chenopod shrubs and browse. Extent of overlap was not clear, because animals may have eaten different species within the groups of plants. The study period did not include any severe drought, in which overlap in diet and competition between animal species would have been most significant.

This study addressed two questions: first, whether the supranormal adherence of blood lymphocytes from patients with multiple sderosis (MS) to endothelial cell monolayers treated with tumour necrosis factor-α (TNFα) was a feature common to other inflammatory disorders; and second, whether the adherence properties of blood lymphocytes from MS patients were related to changes in disease activity and to levels of circulating TNFα and soluble adhesion molecules. In the first part of the investigation, lymphocytes from I 4 patients with MS were more adherent to TNFα-treated endothelial cells(P < 0.01) than those from healthy controls, whereas the adherence properties of lymphocytes from 12 patients with rheumatoid arthritis, eight patients with psoriasis and ten patients with neurological diseases other than MS were normal. In the second phase of the work, measurement of the adhesive properties of lymphocytes isolated at monthly intervals from a further six MS patients over a 5 - 8 month period, found that changes in binding to TNFα-treated endothelial cells, directly paralleled changes in circulating levels of TNFα (r=0.77;P < 0.001) and soluble vascular cell adhesion molecule-I (sVCAM-I)(r=0.67;P=0.001). An increase in disease activity, measured by T2-weighted and gadolinium-enhanced magnetic resonance imaging of the central nervous system (CNS), occurred in two patients and was associated with heightened lymphocyte adhesiveness and a rise in serum TNFα levels. Further analysis of the 34 serum samples from the six MS patients revealed a direct relationship between the concentration of sL-selectin and soluble intercellular adhesion molecule- (sICAM-I)(r=0.65;P < 0.001) and between sL-selectin and sTNFα (r=0.42;P < 0.02). These findings support the view that disease activity in MS is associated with an increased adhesive interaction of blood lymphocytes with vascular endothelium at inflammatory sites within the CNS.

Patterns of dietary selection were examined in the rare bridled nailtail wallaby (Onychogalea fraenata) and compared with those of the black-striped wallaby (Macropus dorsalis) and cattle on the Taunton Scientific Reserve in central Queensland. These two species were considered as possible competitors of 0, fraenata. The dietary niche breadth, the similarity of diet to resources, of 0. fraenata was always narrower than those of the larger species. However, the niche breadths of all species broadened significantly during the driest seasonal conditions, which accounts for the increased dietary overlaps previously reported in these conditions. An analysis of dietary preferences (electivities) showed that 0. fraenata had a high preference for herbaceous plants (forbs and malvaceous species), whereas M. dorsalis and cattle had high preference for grass. During dry conditions the preferred diet of 0. fraenata was considerably different to its actual diet, indicating that the diet was suboptimal. This pattern was not as pronounced in the other herbivores, suggesting that 0. fraenata could be at a competitive disadvantage during these conditions in its last refuge.

The bridled nailtail wallaby (Onychogalea fraenata) is one of Australia's rarest marsupials, persisting only in a small area in central Queensland. Its diet and those of two sympatric herbivores, the blackstriped wallaby (Macropus dorsalis) and domestic cattle (Bos taurus/indicus), were assessed by identifying plant fragments in their faeces. The diet of 0 . fraenata was diverse, consisting of herbaceous plants, grasses and browse. In good seasons the intake was biased towards forbs and other herbaceous plants. Browse was only important when vegetation availability was low. Grass could be a major part of the diet when forbs were scarse. Black-striped wallabies and cattle were largely grass eaters. When conditions were dry, browse contributed up to 16% of the diet of M. dorsalis and 10% of the diet of cattle. Dietary overlap with 0. fraenata was greatest at such times, being above 50% for both species. Potential for dietary competition was apparent and it is suggested that this may have been a factor in the decline of 0 . fraenata with the advancement of European settlement and spread of domestic stock.