A Pictorial Guide to the Kangaroo Culling Issue

Why it is neccessary to reduce eastern grey kangaroo populations at Majura Training Area and Belconnen Naval Transmitting Station in the ACT

• ACT’s wonderful wildlife - there would need to be a very good reason
• Only fragments
• Keystone species and environmental engineers
• To save the beauty, or the beast; that is the question

Figure 1: Many ACT sites are not subject to kangaroo culling, where abundant eastern grey kangaroos (450 / square kilometre) have few significant impacts, and add to visitor enjoyment – this is the Yankee Hat walk in Namadgi National Park, – similar situations are found elsewhere through Namadgi, along the Birrigai Time Trail in Tidbinbilla Nature Reserve, and in urban Canberra.

Figure 2: Plants and animals of the natural temperate grassland, whose numbers and distribution have greatly declined, like this Grassland Earless Dragon, need their habitat protected or they will soon be extinct. Vegetation removal is a threat, e.g. including from heavy grazing by kangaroos.

Figure 3: Eastern grey kangaroos are keystone species in the natural temperate grasslands. They are also ecosystem engineers. Either undergrazing or overgrazing by the kangaroos potentially threatens the survival of other grassland species.

Figure 4: Coorooboorama Raspy Crickets, illustrated here on a native Blue Devil plant (Eryngium rostratum), construct the homes used by Grassland Earless Dragons in the natural temperate grassland. Both species depend on the vegetation layer of this rare ecological community. This cricket is only known to exist in the Canberra vicinity.

Figure 5: Golden Sun Moths (left) eat wallaby grass (Austrodanthonia) species and are dependent on the natural temperate grassland. They have been declared critically endangered by the Commonwealth Government. The Perunga Grasshopper (right) is another grassland dependent species which has been declared threatened.

Figure 7: Kangaroo grazing at Majura Training Area (left) in the drought of 2006–07 removed the habitat of grassland earless dragons whose numbers plummeted. At the same time on the ‘Woden’ sheep property (right), controlled grazing left enough vegetation in place for earless dragons to persist in moderate numbers. Other threatened plants and animals also depend on the vegetation for protection, and would have been similarly affected.

Figure 8: More than 500 kangaroos inside a small fenced area at Belconnen are beginning to damage the natural temperate grassland, and the first few have already died from starvation.

Figure 9: As recently as 2006, the grass at Belconnen was much longer than it is now

Figure 10: Bark is being stripped by hungry kangaroos at Belconnen

Figure 11: The Department of Defence arranged for fertility control to commence at Belconnen in 2007. These four female kangaroos and 36 others were given a prototype experimental vaccine, and returned to the population wearing ear tags. That level of fertility control could be effective in a population of 100 but will have no effect on kangaroo numbers in a population of 500.

Figure 12: Many people find young eastern grey kangaroos much more appealing than grassland earless dragons, striped legless lizards, Ginninderra lepidium and other threatened species of grassland-dependent plants and animals. But our responsibility is to protect them all. Eastern grey kangaroos in the ACT are abundant, increasing and well protected in reserves. They are impacting on grassland-dependent plants and animals in the few remaining ACT fragments of the natural temperate grassland.

Figure 13: There are no known humane, non-lethal alternatives to kangaroo population reduction which are capable of meeting conservation obligations at either the Majura or Belconnen sites. For more reliable information, see the three reports of the Kangaroo Advisory Committee.

Conservation, and Eastern Grey Kangaroos

ACT’s wonderful wildlife - there would need to be a very good reason

The highest densities of kangaroos in the world (kangaroos /sq km) are those in valley-floor grasslands of Namadgi National Park and Tidbinbilla Nature Reserve. These populations of eastern grey kangaroos have few known environmental impacts, and provide a wonderful wildlife spectacle, and opportunities to observe the beauty of eastern grey kangaroos in close proximity, e.g. at the Yankee Hat walk in Namadgi National Park (Figures 1, 3) or the Time Trail in Tidbinbilla Nature Reserve. There would need to be a very good reason before anyone would propose culling in such sites. In fact, as required by ACT government policy , that statement is true of all kangaroo populations in the ACT.

Only fragments

Lowland natural temperate grassland (LNTG) exists as a few fragments of ‘the most endangered vegetation type in Australia’ (Kirkpatrick 1995). Many species have permanently disappeared from LNTG and many others are facing extinction. The individual species tend to be lost from one fragment at a time. There is no longer any fragment with the full set of LNTG species. For example the Ginninderra Lepidium (an endangered plant) survives in only one site. The better known Grassland Earless Dragon (an endangered lizard) (Figure 2), is no longer found in Victoria or most of NSW, and survives in only three populations – Cooma (NSW), Majura Valley (ACT) and Jerrabomberra Valley (ACT). Many other LNTG species are also absent from apparently suitable sites.

Keystone species and environmental engineers

Eastern grey kangaroos are a keystone species in the LNTGs. Their complete elimination may well result in a cascade of extinctions of threatened species, (unless they were replaced by another large grazing animal). On the other hand, too much grazing by kangaroos or other large animals, is also a threat. Prior to habitat fragmentation, heavy grazing may not have mattered much. Species disadvantaged by heavy grazing on one place could recolonise from elsewhere in the vast expanse of grassland. It is also possible that in original natural conditions, kangaroo grazing pressure was moderated by the effect of predators such as the Thylacine and Tasmanian Devil. But in the modern environment, it is impossible for threatened species to recolonise between fragments, and the moderating influence of the dingo, Thylacine and other top predators has been removed. Heavy grazing is the most likely cause of some of the previous losses from some fragments. The important point is that the remaining fragments of the original grasslands depend on moderate grazing. Either over-grazing or under-grazing is a threat (by kangaroos or other large animals).

To save the beauty, or the beast; that is the question

Eastern grey kangaroos are among the most appealing of mammals (Figure 12), while Ginninderra Lepidium, Grassland Earless Dragons, Coorooboorama Raspy Crickets (Figure 4), Striped legless Lizards, Perunga Grasshoppers (Figure5), Golden Sun Moths (Figure5), and other grassland-dependent plants and animals, are all ugly. Well that may be one opinion, but if so, it is irrelevant. Governments are legally and morally obliged to protect each species. Beauty is not a consideration.

This issue involves an abundant and (in the ACT) increasing, species, which is well protected on some sites (eg in Namadgi National Park) and is not proposed to be removed from any site in the ACT. On a few special sites (the LNTG fragments), abundant kangaroos are reducing the populations of rare and declining species, which have been legally declared, in consultative processes, by multiple governments, to be threatened species. That declaration means in practice that special steps need to be taken, or those species will become extinct. Moderation of kangaroo grazing pressure on the LNTG fragments is such a step. It is essential.