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The diet of the brush-tailed rock-wallaby, Petrogale penicillata, was studied at two sites on the central
coast and tablelands of New South Wales over a 12-month period of below-average rainfall. Diet was
assessed by microscopic analysis of faeces. Particles within the faeces were identified to broad categories
of vegetation: grasses, sedges, forbs, parallel-veined shrubs, reticulate-veined shrubs, and ferns. Diets
were similar at both sites despite considerable differences in annual average rainfall (1330 v.577mm)
and vegetation. Grasses constituted 35-50% of the diet, forbs 25-40%, and browse 12-30%. Ferns
and sedges were of minor importance or were absent from the diet. Preferences for particular plant
categories (measured as abundance in diet divided by abundance in habitat) were greatest in summer.
Parallel-veined shrubs and trees and forbs were most preferred at one site; grasses and shrubs and trees
at the other. Ferns were preferred least.

The habitat requirements of the brush-tailed rock-wallaby were assessed by comparing areas of rocky
habitat occupied by this species with adjacent unoccupied areas of similar habitat. Sites occupied by
wallabies had twice the number of ledges, three times the number of caves, and a greater number of routes
from the cliff top onto the face, usually via steep, narrow cracks or chimneys. They invariably faced so
that the cliff received sun for much of the day (a northerly aspect). Rock-wallaby sites averaged twice the
number of ledges sheltered by overhangs as did unoccupied sites. Ledges were shorter on occupied sites,
probably reflecting more restricted accessibility to predators. An equation is presented which predicts
with 90% success from five habitat variables whether a given cliff is suitable for brush-tailed rockwallabies.

Pairs of subjects performed a simple negotiation task over one of three media of communication (face-to-face, closed circuit television, or a loud-speaking audio link). One person was required to argue a case which was consonant with his personal views; the other person was required to argue a case that bore no necessary relationship to his personal views. Medium of communication had a significant effect on the outcome of the negotiation: the side whose case was consonant with his personal views was more successful under face-to-face than under audio-only communication. Results in the video condition resembled those in the face-to-face condition. The findings are interpreted in terms of a greater emphasis on interpersonal considerations (as opposed to interparty considerations) in face-to-face discussions than in audio discussions.

The burrowing buttong (Bettongia lesueur) has been extinct on mainland Australia since the early
1960s, but was believed to persist on four islands off the coast of Western Australia-Bernier, Dorre,
Barrow and Boodie. We surveyed these islands in 1988-89 to ascertain the status of bettongs and other
endangered mammals.
Bettongs were widespread and comparatively abundant on three islands but absent from the fourth.
Bettongs occurred at estimated densities of c. 14-17km-2 on Bernier, Dorre and Barrow Islands,
suggesting approximate minimum populations of 650, 1000 and 3400 respectively and a total minimum
population for the species of c. 5000 individuals. It would appear that a poisoning campaign in 1985
to eliminate Rattus rattus from Boodie Island also eliminated the bettong. The burrowing bettong has
apparently been absent from a fifth island and its type locality, Dirk Hartog Island in Shark Bay, since
early this century.
The vulnerability of this species is highlighted by its extinction on mainland Australia and by
the loss of two of its five island populations. It now occupies less than 0.01% of its historical range.
Its status as rare and endangered is justified.

Spectacled hare-wallabies (Lagorchestes conspicillatus) and euros (Macropus robustus isabellinus) occur
on Barrow I. at densities of 42 and 8 km-2, respectively, which result in estimates of total population
sizes of c. 10000 and 1800, respectively. Spectacled hare-wallabies occur throughout the island in all
habitat types; euros tend to be concentrated in the deeply dissected country in the central-west of the
island. Limited areas of floodout flats are important feeding areas for euros, being the only major
habitat on the island dominated by grasses other than Triodia. There was no significant difference
between density of either species on the two halves of the island (one half is dominated by a commercial
oilfield; the other is relatively undisturbed).
Barrow I. is the smallest island off the Australian coast to have successfully supported a population
of large macropods for the 8000-10000 years since separation from the mainland by rising sea-level.
Hence, the population estimate of euros on Barrow I. provides an empirical measure of the viable
population size necessary for the long-term survival of large macropods. This estimate is nearly two
orders of magnitude less than that estimated from a theoretical model of minimum viable population
size (Belovsky 1987).

Densities of red and western grey kangaroos and euros were assessed by aerial survey and compared
with densities obtained in the same area by drive counts. The survey area (12.1 km2) was long, narrow
and sparsely vegetated. Lakes and a kangaroo-proof fence bounded the area on three sides facilitating
the drive count. Densities from aerial surveys ranged between 38 and 54% of the corresponding drive
counts for red kangaroos, between 15 and 23% for western grey kangaroos, and between 9 and 10%
for euros. The time of morning at which the surveys were conducted altered these percentages. About
twice as many red and western grey kangaroos were counted on aerial surveys at sunrise compared to
surveys 3.5 h later.

Observed densities of emus, Dromaius novaehollandiae, estimated from aerial surveys were compared with
results of a drive count in 1985 and 1986. The study area was mostly open shrubland. True density of emus
was 2.56 per km2 in 1985 and 1.15 per km2 in 1986. Aerial survey estimates were 66 and47% oftrue density in
the two years, respectively, and the weighted average was 60%. Over the limited range tested ofeach variable,
observed density was not significantly affected by temperature, cloud cover or time of day.

The densities of red and grey kangaroos in western Victoria and south-eastern South Australia were
assessed by aerial survey. Much of the 133000-km2 area surveyed was farmed intensively for wheat and
sheep but a significant proportion was largely unaltered mallee woodland or mallee heath. Of the total
area, 85% had a density of less than one kangaroo per square kilometre, and 32% had a density of less
than 0.01 km-2, values considerably lower than those reported for pastoral areas in New South Wales
and South Australia. Low densities in settled areas are attributed to intensive agricultural practices, small
landholdings and lack of tree cover. Low densities in mallee may be due to the lack of palatable grasses
and the absence of permanent watering points.

Emus are most abundant in areas used for extensive sheep grazing. Their density is lower in
grain-growing areas, lower still in areas used for extensive cattle grazing, and lowest in those areas that
are not used for any commercial purpose (mainly deserts). This pattern of emu density appears to be
linked to climatic factors determining the availability of food during breeding, to the availability of
naturally occurring and artificially stored surface water, and to the prevalence of dingos.