Examination of kidney structure for 25 dasyurid marsupials showed that kidneys of species from arid habitats tend to have a relatively thicker medulla and higher renal indices than those of species from semi-arid, mesic and tropical areas. Arid-dwelling species such as Ningaui ridei and Pseudantechinus macdonnellensis had the highest renal indices while Antechinus swainsonii, collected from alpine environments, had the lowest renal index values. Renal indices were significantly correlated also with body weight, average daily maximum temperature and average annual rainfall of the habitat. The renal indices for xeric species differed significantly by discriminant analysis from the indices for other species. There was no obvious phylogenetic conservatism in renal indices; for example, renal indices varied almost as much within the genus Sminthopsis as between all of the other genera of Dasyuridae examined.

The thick-billed grasswren (Amytornis textilis) has a disjunct distribution in the Shark Bay region, with one population confined to Peron Peninsula and the other further inland on Woodleigh Station and the north-eastern corner of Hamelin Station. Grasswrens were found in several vegetation types, including acacia shrublands, Triodia spinifex and the dense vegetation in drainage depressions. Vegetation characteristics that appeared important determinants of grasswren presence were recumbent acacias and low shrubs within the 0–1-m height category, and shrub clumps of high foliage density. These shrub clumps comprised climbers and recumbent low shrubs with interwoven branches, often in association with other plant species. Habitats with this shrub structure may provide the grasswren with ideal nesting sites. The possible effects of grazing and fire on this shrub structure are discussed.

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The renal vasculature of two dasyurid marsupials, Sminthopsis dolichura and S. crassicaudata, was examined using scanning electron microscopy of vascular corrosion casts of the kidney. Each species had a pair of unipapillary kidneys and the structural organisation of the major renal arterial vessels was similar to that of other placental mammals. The glomerulus of both species consisted of a network of dividing and anastomosing capillary loops. The glomeruli varied markedly in size, shape and complexity. Some afferent arterioles extended back towards the renal medulla, positioning the glomeruli closer to the cortico-medullary border. This placement of glomeruli may extend the loop of the nephron further into the medulla and thereby enhance counter-current water reabsorption and the final urine concentration. In both S. crassicaudata and S. dolichura, a dense mesh of numerous fine capillaries lined the wall of the renal pelvis adjacent to the inner medulla, with a unique configuration in that they were aligned perpendicular to the vasa recta. The function of these fine capillaries is unknown.

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