Academic literature on the topic 'Bridled Nailtail Wallaby'

Diets and feeding selectivities of sympatric bridled nailtail wallabies, Onychogalea fraenata, and black- striped wallabies, Macropus dorsalis, were studied at two sites during each season on Taunton Scientific Reserve, Queensland. Bridled nailtail wallabies ate a wide variety of monocotyledon and dicotyledon species (>60) in broadly equal proportions. During dry seasons, there was a marked switch to dicotyledons, including woody browse species, which formed over 20% of material in faecal pellets. In contrast, black- striped wallabies were predominantly grazers, eating a wide variety of grasses and sedges (>65 spp.). Compared with black-striped wallabies, bridled nailtail wallabies were much more selective in their feeding, both for individual plant species and plant parts. Bridled nailtail wallabies selected against grass species, particularly during the dry season, and showed high selectivity for forbs in areas where these were scarce. Black-striped wallabies generally selected against forbs and showed random selection for grass species. Bridled nailtail wallabies showed stronger selection for food items of relatively high nutritional value (such as leaves and seedheads), and stronger selection against items of relatively high fibre content (such as grass stems) than did black-striped wallabies. Dietary overlap varied seasonally and was highest during spring and summer. The potential for inter-specific competition was highest during spring, when food resource abundance was lowest. The feeding niche of bridled nailtail wallabies is narrower than that of black-striped wallabies, indicating that the effects of competition may not be symmetric between the wallaby species. The results of this study agree with those of previous work on these species.

The bridled nailtail wallaby (Onychogalea fraenata), an endangered macropod, has been reintroduced into the wild after a captive-breeding program. As part of a management program to assess the risks to its survival O. fraenata were trapped and examined for ecto- and endoparasites. From February to September 1996, 55 wallabies from Taunton National Park, central Queensland, some trapped more than once, were visually examined for ectoparasites. The blood of 39 O. fraenata was tested for antibodies against Toxoplasma gondii and Echinococcus granulosus and a total of 82 faecal samples were examined microscopically. In addition, in a second study a complete carcase, three complete gastro-intestinal tracts, and a single stomach, obtained from various sources, including Idalia National Park, were examined for helminth parasites. The most prevalent ectoparasites were the ticksAmbylomma triguttatum and Haemaphysalis bancrofti. Other ectoparasites included four species of trombiculid mites and a louse, Heterodoxus sp. A single instance of the nippoboscid fly, Ortholfersia minuta, was found. From the serological surveys, antibodies against Toxoplasma and Echinococcus were detected in 15% and 21% respectively. No trematode or cestode eggs or protozoal cysts were found in faeces. Nematode eggs had a prevalence of 92% with a mean egg density of 500 eggs per gram. Strongyloides sp. (larvae) was the most prevalent nematode in faeces. In the postmortem study, seven nematode species (Cloacina polyxo, Hypodontus macropi, Labiostrongylus onychogale, Macropostrongyloides baylisi, Macropoxyuris sp., Rugopharynx australis and Zoniolaimus buccalis) and four cestode species (Progamotaenia bancrofti, P. zschokkei, P. abietiformis and larval E. granulosus) were found. Six of the nematode species are new host records. The presence of infection with the introduced parasites T. gondii and E. granulosus, both recognised as serious pathogens, is of management significance. Since the definitive hosts of these parasites are cats and canids respectively, control of cat, dog and dingo populations within the Park will lessen the incidence of infection with these parasites.

Context The loss of large predators has been linked with the rise of smaller predators globally, with negative impacts on prey species (mesopredator release). Recent studies suggest that the dingo, Australia’s top terrestrial predator, inhibits predation on native mammals by the invasive red fox, and therefore reduces mammal extinctions. Feral cats also have negative effects on native mammals, but evidence that dingoes suppress cats remains equivocal. Aims We sought to examine whether dingoes might spatially or temporally suppress the activity of feral cats at a site containing the sole wild population of an endangered macropod subject to feral cat predation (the bridled nailtail wallaby). Methods We used camera traps to compare coarse and fine-scale spatial associations and overlaps in activity times of mammals between August 2009 and August 2010. Key results Dingoes and cats used the same areas, but there was evidence of higher segregation of activity times during wet months. Potential prey showed no spatial avoidance of dingoes. Peak activity times of dingoes and their major prey (the black-striped wallaby) were segregated during the wetter time of year (December to March). We did not find evidence that cats were spatially excluded from areas of high prey activity by dingoes, but there was low overlap in activity times between cats and bridled nailtail wallabies. Conclusions These findings support the contention that fear of dingoes can sometimes affect the timing of activity of feral cats. However, cats showed little spatial avoidance of dingoes at a coarse scale. Implications Control of dingoes should not be abandoned at the site, because the potential moderate benefits of reduced cat activity for this endangered and geographically restricted wallaby may not outweigh the detrimental effects of dingo predation.

The reproduction of the endangered macropod Onychogalea fraenata was studied in captivity. O. fraenata breeds throughout the year. A post-partum oestrus was not recorded, although mating during the pouch life was observed when the pouch young were 80–92 days old. The mean length of the oestrous cycle was determined to be 36·2 days, while the mean length of a gestation period was 23·6 days. Pouch life ranged between 119 and 126 days, and the young males and females matured as early as 270 days and 136 days, respectively.

Predation by introduced foxes and cats is generally thought to be the main reason for the poor success rate of macropod reintroductions on the Australian mainland. Predator-prey theory suggests that predation may have particularly severe impacts on very small populations, especially if a more common primary prey species is present (such as the rabbit). Thus, a sufficiently large reintroduction may overcome predation and succeed where a smaller one would fail. The minimum viable population would, however, be much larger than that predicted by standard population-viability analysis. We use a simple stochastic model based upon the bridled nailtail wallaby to explore this possibility. Even very small amounts of predation (2-4 individuals per six months) can be sufficient to cause reintroductions of up to 50 animals to fail. No clear threshold population size beyond which reintroductions will succeed is evident and, for a given mean, the probability distribution of predation has a very limited impact on the success of reintroductions. In almost all circumstances, a single reintroduction of a given size is preferable to multiple reintroductions of the same total number of individuals.

The bridled nail tail wallby, Onychogalea fraenata, was once locally common throughout most of its range. That range included much of eastern Australia from south of the Murray River in Victoria to Charters Towers in North Queensland. Today one small population is known to survive on an area of approximately 100 sq.km near the small township of Dingo in Central Queensland. Taunton Scientific Reserve was gazetted in 1979 to preserve much of the remaining bridled nailtail wallaby population and the habitat in which it survives. The study area for this work covered 3 129.3 ha and included all of the western end of the scientific reserve. The objectives of the project were to determine the distribution of the bridled nailtail wallaby population in the study area, to identify habitats used for shelter during daylight hours, to describe the preferred raicrohabitats in terms of the structural characteristics of the vegetation, and to investigate the use of habitat including activity patterns, diet and water usage. To determine the distribution and habitat preferences of the bridled nailtail wallaby a compass transect grid system with 130 m between transects was developed to ensure all of the study area was sampled. The transects were sampled three times per year over two years. Each sampling session required 21 days to complete with the first session in October 1980 and the last in May 1982. The locations of all nailtails encountered were mapped and the vegetation type noted. There was a total of 144 bridled nailtail wallaby sightings during the six sampling session. The vegetation on Taunton was classified into four major types, (a) dense Acacia forest, (b) open grassy Eucalyptus woodland, (c) cleared areas and (d) the transitional vegetation type that formed a narrow 'band' between the dense Acacia forest and the open grassy Eucalyptus woodland. Sixty-three percent of bridled nailtail wallaby sightings occurred in the transitional vegetation type that covered only 14 percent of the study area. A further 25 percent of sightings occurred in the open grassy Eucalyptus woodland with an area of 39 percent. As most nailtail sightings occurred in the transitional vegetation type this vegetation type appears to be the habitat type most preferred by bridled nailtail wallabies for daytime shelter. This vegetation type is dominated by brigalow, Acacia harpophylla, and is structurally and floristically similar to the dense Acacia forest. It differs in that the brigalow trees tend to be smaller and clumped with clumps of trees separated by open spaces of approximately the same area as the clumps. This study also examines the microhabitat preferences of the bridled nailtail wallaby in the four major vegetation types on Taunton. Twenty -two variables describing proximate habitat structure were measured at each bridled nailtail wallaby sighting. They described the physical characteristics of the vegetation in a circular quadrat of 20 m diameter centered on the resting place (form) from where the nailtail had been flushed. As a control similar sized quadrats at randomly chosen sites were sampled for the same microhabitat variables. Thirty-two different sites were chosen for each session giving a total of 192 sites for the six sampling sessions. For the nailtail sightings there were significant differences between sightings in the four major habitat types on 13 of the variables. For the randomly chosen sites there were significant differences between the major vegetation types on 18 of the variables. To obtain a tighter definition of microhabitat types, cluster analysis was used to group sightings that had similar vegetation structure. Each major vegetation type was analyzed separately. This technique proved effective and microhabitat types preferred for resting and sheltering during the day were described for three of the four major vegetation types. Eighty -two percent of bridled nailtail wallaby sightings occurred within 100 m of the edge between the dense and open vegetation types. The importance of the edge to the nailtail and how it uses its preferred habitat were investigated and are discussed in terms of shelter and predation. The bridled nailtail wallaby was found to be a solitary animal with a bimodal activity cycle tied to a solar rhythm. Typically, it feeds in the ope~ Eucalyptus woodland at night and rests and shelters in the dense Acacia forest by day. The nailtails' colouration and behaviour are well adapted to avoiding detection by predators. Destruction of habitat quality increases the nailtails' susceptibility to predation by the dingo. This is suggested as a major contributing factor in the decline of the species. Aspects of diet, the seasonality of reproduction, and competition from the black-striped wallaby (Macropus dorsalis) and feral cattle were also investigated. The bridled nailtail wallabys' diet consists of 40 percent - 50 percent graze and the rest browse. The nailtails' main obvious competitor for food and space is M.dorsalis. That species' diet was found to consist of between 81 percent and 96 percent graze, depending on the season, with the remainder made up of browse. The diet of cattle was found to consist almost entirely of grasses. Neither of these species demonstrated significant competition with the bridled nailtail wallaby, either for food or for space. Competition for space occurs infteqnently, mainly towards the end of the dry season when better quality food is scarce. Although bridled nailtail wallaby pouch young were observed during most seasons, the majority of large pouch young were observed during mid- to late summer with a smaller peak during winter.

 The Bridled Nailtail Wallaby, Onychogalea fraenata, was once widespread throughout eastern and south-eastern Australia, but is now found primarily at Taunton National Park (Scientific). With a population reduced to fewer than 500 individuals, survival of the species is dependent on the sustainability of suitable habitat in the present, and its continued availability in the long-term. 

While dietary selection and habitat utilisation have been investigated, the interrelationships between nailtail habitat components have not been examined. This study was conducted to address that issue. The aim was to develop a method of predicting nailtail populations in diverse habitats, with the ultimate goal being the identification of habitat conducive to continued nailtail survival. 

Data were gathered from six sites on Taunton National Park. Two sites corresponded to each of the following categories: low, medium and high nailtail population levels. These sites were examined to determine trends or patterns resulting in significant correlations between nailtail density and the floristic and shelter components. Components were found to fall within two basic habitat types: one favourable and the other unfavourable to the nailtail. 

In the favourable "Acacia habitat," interrelated floristic components consisted of Acacia trees and shrubs, Capparis, Opuntia, Schlerolaena and Parsonsia herbs, Capparis, Schlerolaena and Carissa shrubs, and Cenchrus, Cyperus, Paspalidium  and Sporobolus grass. Shelter components were comprised of Solid Logs, combined Solid Log -Hollow Log, combined Solid Log -Hollow Log -Woodpile, Shrub and combined Brigalow Regrowth -Shrub. 

In the unfavourable "gum -tree habitat", floristic components consisted of Eucalyptus, Cotymbia and Grevillea trees, Alphitonia, Eucalyptus, Grewia, Sida and Phyllanthus shrubs, Euphorbia, Cheilanthes and Hybanthus herbs, and Aristida, Eragrostis and Eriachne grass. Shelter components consisted of Trees, and variations of tree shelters to include Fallen Tree Crown, combined Tree -Live Tree Crown, combined Tree -Live Tree Root, and combined Tree -Live Tree Crown -Live Tree Root. 

To validate these proposed habitats, three additional study sites were selected on the Pine Grove, Red Rock Park and Rockview cattle properties adjacent to Taunton National Park. Based on habitat composition at these sites, the Pine Grove site was determined to be a low -to -medium nailtail density site; Red Rock Park a low -to - medium nailtail density site with the potential to support a high density of nailtails; and Rockview a medium nailtail density site. 

Based on the results of this study it is recommended that management of existing nailtail habitat incorporate the balanced mix of habitat components noted in the "Acacia habitat" while controlling the spread of "gum -tree habitat" components. Emphasis on floristic and shelter interrelationships is also considered essential in the establishment of future nailtail populations.