Rusa Deer Australia
Rusa is the Malay word for deer and they are medium sized, rough-coated deer which are biologically allied to the sambar. However, the two species are quite different in size, appearance and behaviour. There are two subspecies established in the wild in Australia and the Javan rusa (Cervus timorensis russa) is the larger. Stags stand up to 110cm at the shoulder and may weigh around 136kg while hinds are considerably smaller at 95cm and 60kg.
The coat hair is coarse and sparse and generally a greyish brown in colour although the shade varies between the age groups and sexes and also season-ally. The underparts including the chest and throat are a light grey, almost white in some cases, which is a striking contrast to the main body colour, and there is a line of dark hair which runs down the chest between the forelegs.
Ears are pointed, with tufts of long light coloured hair in the upper part of the inner ear, and the skin of the nose is dark brown. There is a pre-orbital gland under the eye, as in sambar, but the rusa's gland is not so prominent.
A rusa stag's antlers are quite large, in comparison with its body size, and very distinctive with a typical lyre shape. There is a brow tine, which is often curved, and a terminal fork at the end of the main beam. The thicker part of the main beam continues on into the back tine and this is normally considerably larger than the front tine. In good conditions, a mature rusa stag may grow antlers up to and sometimes exceeding 76cm in length. Most stags cast their antlers in January or February.
Compared to their close relative the sambar, rusa are very vocal, and their calls range from an alarm bark to a low, barely audible, vibratory communication between hinds and calves, or the loud shrill sound of rutting stags.
In the nineteenth century many rusa were liberated in New South Wales, Victoria and Western Australia but now these have all disappeared, except for those deer situated in the Royal National Park in New South Wales and others which have infiltrated into new country south of the Park.
For many years, visitors to the Royal National Park were able to observe the deer living naturally in their rugged environment and some deer were attracted to the most often visited areas by food scraps. These soon became easily approachable and the rusa of the Royal National Park became the most photographed wild deer in Australia. The New South Wales National Parks & Wildlife Service has for many years carried out an eradication campaign aimed at completely wiping out rusa in the Park because they are an introduced species. The wildfires of 1994 temporarily destroyed most of the vegetation in the Park, making the surviving rusa much more vulnerable to this operation. No conclusive evidence has ever been produced to show that the deer had any serious detrimental effect on the Park environment, so the deer are victims of the anti-exotic philosophy so common among our wildlife managers.
Another successful liberation, this time of the Moluccan rusa (Cervus timorensis moluccensis), was carried out in 1910 on Friday Island at the tip of Cape York Peninsula. These deer are now more widely distributed and can be found on Prince of Wales and Possession Islands, Groote Eylandt, and have also been reported on the Queensland mainland.
Breeding and Reproduction
Rusa do not have a regular reproductive cycle but most of the breeding activity does occur during July and August, with a subsequent peak calving time in March and April. Individual hinds may cycle earlier or later and, as is the case with many tropical deer species, there will usually be a stag in hard antler available to accommodate them. The result is that young calves may be observed at widely varying times of the year. The calves are not spotted but are born with adult colouring. Twins are not uncommon. When they are sexually aroused, or 'rutting', the rusa stags wallow and thrash vegetation such as reeds, tussocks and bracken fern. A stag will lower his antlers and 'plough' the vegetation, with the result that a large bundle of greenery is gathered and carried on top of his antlers to intimidate the other deer. Rusa stags do not fight as often as some other deer species but use this antler decoration as a measure of their dominance. The bigger, stronger stags can obviously assemble a much bigger bundle of vegetation.
Rusa are gregarious animals and live in groups. Except during the main breeding season, the stags form separate groups to the hinds and younger animals. They depend heavily on grasses for food although they are known to enjoy eating certain seaweeds and will drink seawater on occasions. Rusa do not appear to have the same amount of essential 'wildness' as some other deer species in Australia.
With sympathetic management, Rusa could have a good future in those parts of the country where they have already demonstrated their ability to survive. Certainly, in New South Wales at least, the professional wildlife managers are working seriously to eradicate the deer and they have no protection in Queensland. The only force powerful enough to reverse this trend is public opinion.