Red-necked Wallaby Macropus Rufogriseus Research Articles

The Effect of Visitor Number on the Behavior of Zoo-Housed Macropods

ABSTRACT Free-range exhibits are used by zoos to allow visitors to experience or interact with animals in a semi-natural setting; close interactions with animals have been shown to increase empathy and contribute to conservation outcomes, and as such zoos are increasingly implementing free-range style exhibits to facilitate this goal. We aimed to investigate whether this close proximity to zoo visitors impacted upon four species of macropod (red kangaroo Macropus rufus, red-necked wallaby Macropus rufogriseus, swamp wallaby Wallabia bicolor, and quokka Setonix brachyurus) in a free-range exhibit in an Australian zoo. Specifically, we used instantaneous scan sampling to assess animal behavior and examined whether visitor number affected the proportion of individuals that exhibited four target behaviors; visitor-directed vigilance, retreat, resting, and foraging behavior. We found that the proportion of individuals exhibiting visitor-directed vigilance significantly increased as pedestrian visitor number increased for three of the four species, and the proportion of individuals that were resting was significantly negatively related to visitor number for both wallaby species. The proportion of individuals of each species foraging or retreating was unrelated to visitor number. These data suggest that a visitor effect exists in a walk-through exhibit of macropods, and once visitor numbers go beyond a threshold, the behavior of more animals is impacted, likely compromising welfare. Interestingly, quokka do not appear to be affected by zoo visitors; which may be due to visitor pressure being perceived differently due to evolutionary differences, or that housing and husbandry ameliorate the visitor effect for this species but not others. Like many studies before, taking a species-specific approach to understanding zoo visitor–animal interactions has determined how the visitor effect likely impacts macropods differently.

Macropod habitat use and response to management interventions in an agricultural - forest mosaic in north-eastern Tasmania as inferred by scat surveys

Context Native pest herbivores often require population numbers to be controlled in landscape settings where agricultural, plantation forests and native forests are juxtaposed. The Tasmanian pademelon Thylogale billardierii and the red-necked wallaby Macropus rufogriseus rufogriseus are among the most abundant native pest herbivore species in Tasmania. Aims We aimed to determine the habitat use of pademelons and wallabies in response to (i) environmental and seasonal variation, and (ii) two different wildlife management interventions (shooting and fencing) in an agricultural–forest mosaic in north-eastern Tasmania. Methods Macropod abundance before and after shooting and fencing management interventions were estimated by changes in the rate of deposition of faecal pellets (scats per unit area per time interval) on an array of permanent transects that were stratified across three habitat types (agricultural land, plantation forest, and native forest). An experiment was also conducted to determine the endurance of fresh scats in the three habitats. Key results More than 90% of scats remained undecomposed for over five months, and more than 50% of scats remained undecomposed for over 11 months across the study site. Decomposition rates were significantly influenced by habitat type, specifically, highest in agricultural land and lowest in native forest for both species. Scat deposition rates showed that species abundance was influenced by habitat type and season. Macropod abundance was highest in agricultural land and lowest in native forest. Compared with summer and early autumn, pademelon scat abundance significantly decreased in late autumn and spring on agricultural land but showed no change for plantation forest or native forest. Wallaby scats showed similar seasonal trends for all three habitats, lower in late autumn and spring compared with summer and early autumn. Following each of the management interventions, macropod scat deposition rates decreased predominantly on agricultural land. This effect decreased with increasing distance from intervention loci. Conclusions We demonstrate that scat monitoring provides a useful survey technique for the assessment of macropod habitat use, and show that macropods select for agricultural habitats. Shooting and fencing interventions reduced the use of agricultural habitats, but this effect was localised. Implications A whole-landscape perspective is required when assessing the impacts of management interventions on pest populations. Results highlight the formidable challenges in controlling native herbivores in habitat mosaics, given the localised effects of management interventions and the importance of environmental and seasonal factors as drivers of habitat use.

Terrifying tourists and wary wallabies: responses of macropodid species to the presence of humans

The responses of four species of macropodid to humans at a wildlife sanctuary were investigated experimentally. Bridled Nailtail Wallabies Onychogalea faenata, Red-necked Wallabies Macropus rufogriseus and Swamp Wallabies Wallabia bicolor all spent less time feeding, resting, grooming, interacting and more time looking up or moving in the five minutes after being approached by the researcher. Eastern Grey Kangaroos M. giganteus, Red-necked Wallabies and Bridled Nailtail Wallabies fled at shorter distances from an approaching researcher in a vehicle than from a researcher on foot. The proportion of macropodids found in grassland compared with forest was not significantly affected by a recent tour.

Macropod studies at Wallaby Creek. 6. A validation of the use of dung-pellet counts for measuring absolute densities of populations of macropodids

Densities of red-necked wallabies Macropus rufogriseus banksianus and eastern grey kangaroos M. giganteus at Wallaby Creek were estimated from dung-pellet counts, and these estimates were compared with the actual densities, known from censuses of individually recognisable animals. Rates of pellet accumulation were measured by clearing and re-surveying permanently marked plots. Trials measured the rates at which pellets disappeared, and defaecation rates were measured in a concurrent study. Pellets disappeared quickly during warm, moist conditions (and at rates which varied with habitat), but survived well in cold, dry conditions. Winter is considered to be the most appropriate season to run dung-pellet surveys in this or similar environments. Dung-pellet surveys estimated red-necked wallaby density with consistent accuracy, regardless of whether counts of individual pellets or counts of pellet groups were used. Counts of individual pellets underestimated grey kangaroo density, but counts of pellet groups returned more accurate estimates. Inaccuracies in previous estimates of macropodid density derived from dung-pellet surveys appear to have been due to the inappropriateness of defaecation rates measured on captive animals.

Provisional mapping of the gene for a cell surface marker, GA-1, in the red-necked wallaby Macropus rufogriseus.

A series of M. rufogriseus-mouse somatic cell hybrids was constructed and analysed cytologically, enzymatically and immunologically. A monoclonal antibody, GA-1, was prepared against an M. rufogriseus cell surface antigen on an M. rufogriseus-mouse somatic cell hybrid. A gene determining the expression of this antigen was provisionally assigned to the long arm of the M. rufogriseus chromosome 3. The monoclonal antibody also reacted with an M. rufus (red kangaroo)-mouse somatic cell hybrid containing only the M. rufus chromosome 5, the G-banded chromosome identical to M. rufogriseus 3q. The results also suggest synteny of the genes for the marsupial enzymes hypoxanthine phosphoribosyltransferase and phosphoglycerate kinase-A.