Distribution Of Kangaroos Research Articles

The interdependence of fire, grass, kangaroos and Australian Aborigines: a case study from central Arnhem Land, northern Australia

AbstractAim To describe the nexus between Aboriginal landscape burning and patterns of habitat use by kangaroos in a tropical savanna habitat mosaic, and to provide evidence to evaluate the claim that Aboriginal landscape burning is a game management tool.Location Central Arnhem Land, a stronghold of traditional Aboriginal culture, in the monsoon tropics of northern Australia.Methods The abundance of kangaroo scats was recorded throughout a landscape burnt by Aboriginal people, and used as a proxy for the intensity of habitat use by kangaroos. Scat abundance was assessed along field traverses totalling 112 km, at three time periods: (1) 1–4 weeks following mid‐dry season burning (July 2003); (2) in the late dry season (November 2003); and (3) in the following mid‐dry season (July 2004). We compared the intensity with which kangaroos used burnt vs. unburnt areas in various habitat types, with time since mid‐dry season burning. Scats were collected from areas that had been burnt to a varying extent and the abundance of carbon and nitrogen stable isotopes (δ13C and δ15N) and carbon to nitrogen ratios (C : N) determined.Results There was clear evidence of an interaction between burning and habitat type on the abundance of kangaroo scats. Scats were much more abundant in burnt vs. unburnt areas in the moist habitats, but the opposite effect was observed in the dry rocky habitats, with higher scat abundance in unburnt areas. This interactive effect of burning and habitat type on scat abundance was observed immediately (< 4 weeks) following fire, and was still present one year later. High concentrations of nitrogen in resprouting grasses indicate that burnt areas may provide kangaroos with greater access to nutrients. The isotopic composition of scats indicates that kangaroos feeding in extensively burnt areas were consuming more grasses, and possibly sedges, than kangaroos feeding in unburnt areas.Main conclusions The fine‐scale mosaic of burnt and unburnt areas created by mid‐dry season Aboriginal landscape burning has clear effects on the distribution of kangaroos. Kangaroos move into burnt moist habitats and away from burnt dry, rocky habitats. Isotopic analysis of scats suggests that the mechanism driving this effect is the increased abundance of nitrogen rich grasses in burnt moist habitats.

The Efficacy of Finlayson Troughs as a Means of Repelling Kangaroos From Water and Altering Grazing Pressure in Pastoral Areas.

We attempted to determine whether Finlayson troughs (a selective electric repellent device) would repel kangaroos (Macropus rufus and M. robustus) but still allow sheep to drink when access of kangaroos to artificial water sources was restricted on a large scale, and the effect that had on kangaroo populations. In late 1993 high percentages of kangaroos (over 80% of both species) were repelled from water sources fitted with Finlayson troughs when alternative water sources were available. However, when all water sources within a 100,000 ha area had activated Finlayson troughs or were fenced off, kangaroos found methods that enabled them to circumvent the Finlayson troughs within two weeks after activation of the troughs. The numbers which were able to obtain a drink increased greatly over this period. When used on a large scale, Finlayson troughs as used in this study were thus apparently ineffective in restricting the access of kangaroos to water. Aerial surveys and radio-tracking were used to determine the numbers and distribution of kangaroos over the whole area after activation of all the Finlayson troughs. There were no significant differences in kangaroo numbers between the treated area and a nearby control area which was devoid of Finlayson troughs. All 31 of the radio-collared kangaroos which could be located at the end of the trial remained within the areas they formerly occupied and the length of their movements did not increase.

Habitat mapping by landsat for aerial census of kangaroos

Landsat MSS imagery was used to map habitat categories used in connection with aerial census work that estimates population levels of kangaroos. A study area featuring typical habitat patterns was selected in the marginal wheat lands of southern, inland Queensland. A series of unsupervized classifications of the imagery provided accurate estimation of the relative proportions and distribution of these habitats. The data form a useful base for programmes that: monitor the numbers and distribution of kangaroos; and attempt of refine aerial census methodology.

NUmbers and Distribution of Kangaroos in the Queensland Pastoral Zone

Kangaroos were censused in the pastoral zone of Queensland (537000 km2) and in an area abutting it to its west (90000 km2) during the winter of 1980. Red kangaroos, Macropus rufus, occurred throughout the survey area but concentrated in its south-west, and also to the west of Winton. Eastern greys, Macropus giganteus, attained high or very high densities in the south-east of the survey area, with medium densities along its eastern margin. Numbers within the survey area were estimated as 1.8 million red kangaroos and 3.0 million grey kangaroos, at overall densities of 2.8 and 4.7 km-2 respectively. Densities within the pastoral zone were not grossly in excess of those outside it, in contrast to the position in some of the other states. Extrapolation of mapped density isoclines suggests that these two species of kangaroos in Queensland as a whole number about 2.3 million red kangaroos and 5 million grey kangaroos. The legal Queensland kangaroo harvest in 1980 took about 10% of the total population of each species.

Mobility of the Red Kangaroo, Megaleia rufa

The distribution and abundance of red kangaroos was studied in inland New South Wales by a series i f aerial surveys. Thro'ughout the study the population density of kangaroos fell sharply in each area studied and there is little doubt that a drastic decline occurred in the number of red kangaroos in in!and New South Wales during the period April 1960 to January 1963. Possible causes are discussed. The distribution of kangaroos was determined by the abundance of short green grass; long herbage was avoided as were dry pastures. The greatest abundance of animals occurred on Danthonia and Stipa grasslands, especially where shade was available from clumps of timber and where local movements were controlled by the availability of forage. In the study area with the milder climate, red kangaroos were very sedentary, but in the more arid area rather more extensive movements occurred in response to the changing distribution of green herbage. It is suggested, however, that red kangaroos were, on the whole, not stronlgly nomadic in the period studied.