Myth or Reality?

Much of the ‘folk wisdom’ and material found on the internet about kangaroos, is untrue of eastern grey kangaroos in temperate areas such as the ACT. Chapter 3 in the ACT Kangaroo Management Plan contains factual explanations for many misconceptions.

Myth 1:
Kangaroos control their own fertility and do not produce any more young than the environment will support.
Reality: In temperate Australia, female eastern grey kangaroos produce young at a rate which depends mainly on the mother’s age, rather than on the weather or the food supply. That remains true even in drought. It is possible for 60 per cent more animals to be added to a population each spring when the young emerge from the pouch. Overproduction is the norm although exceptions occur. When a food shortage is so extreme that the breeding adults are dying, young kangaroos can also die in the pouch but such extremes are uncommon in temperate areas.

Myth 2: Kangaroos give birth continuously in every season.
Reality: The Eastern Grey Kangaroos seasonality of breeding increases with latitude. In natural populations in the ACT region, more than 80 per cent of eastern grey kangaroos are born in the twelve weeks from the last week of November.

Photo: As a result of the seasonal breeding pattern, in spring a high proportion of adult female eastern grey kangaroos in the ACT can be seen with large pouch young, evident as bulgy white pouches. The non-breeding females in the following illustration are sub-adults 17-19 months old, which are still following their mothers.

Myth 3: The ACT has about the same number of kangaroos per square kilometre as NSW.
Reality: There is no comprehensive count of kangaroos across the entirety of any state or territory but several pieces of evidence indicate the ACT and nearby parts of NSW have an exceptionally high density of kangaroos. It is known that temperate areas can support much higher kangaroo densities than the semi-arid inland plains. The much higher incidence recorded of motor vehicle accidents in the ACT and surrounding NSW is also an indicator of higher densities of kangaroos (Reference: Ramp and Rodger, 2008). Refer to Sections 3.7.4 and 6.7 of the ACT Kangaroo Management Plan Chapter 1, Appendix 6.

Myth 4: Kangaroos cannot eat themselves out of food. Reality: Populations of large herbivores around the world, including kangaroos, are known to increase rapidly in the absence of predators and when there is a plentiful food supply. This sometimes leads to a situation in which the herbivore population ‘overshoots’ its food supply, then declines rapidly due to mass starvation. These ‘herbivore irruptions’ have occurred in eastern grey kangaroos in the ACT region. Refer to Section 3.2.4(d) of the ACT Kangaroo Management Plan.

Photo: An area of endangered yellow-box red-gum woodland community eaten out by eastern grey kangaroos in 2008. No other large herbivores graze here. Fenced areas where kangaroos are largely excluded have not been impacted by grazing.

Myth 5: Kangaroos move to where there is food.
Reality: Eastern grey kangaroos are not nomadic or migratory. Radio tracking studies in temperate areas show they are faithful to a home range. Genetic studies have suggested that long distance movements must occur from time to time, most likely by individuals. See Section 3.2.2 of the ACT Kangaroo Management Plan.

Myth 6: One native species (such as kangaroos) cannot harm another native species.
Reality: There are numerous examples of native species increasing to harmful levels and thereby impacting on other native species. Two examples of this include the noisy miner bird, which is known to drive out other woodland bird species and the pied currawong, which will eat the young of small native birds in urban areas. There is evidence that the effect of kangaroo grazing has impacted on grassland earless dragon populations in the ACT. The ACT Kangaroo Management Plan covers this issue in section 1.4.1 and Section 3.8.4.

Photo: Grassland Earless Dragon in Tussock

Myth 7: Eastern grey kangaroos are facing extinction.
Reality: There are numerous lines of evidence to contradict this myth. There is significant scientific evidence that shows that the four large commercially harvested kangaroo species, including the eastern grey kangaroo, are ‘common’ or ‘abundant’ (Reference: Van Dyck and Strahan 2008). Section 1.2.1 of the ACT Kangaroo Management Plan summarise the state of knowledge and contested views, with further details in Sections 3.1.1 and 6.6. 

Myth 8: Fertility control should be used instead of lethal methods.
Reality: As yet there is no form of kangaroo fertility control applicable to free ranging wild populations. Refer to Section 4.6.2 of the ACT Kangaroo Management Plan for a full explanation.

Myth 9: All kangaroo shooting is inhumane.
Reality: Investigations, both national and local, have consistently found that adult kangaroos are humanely killed when shot by experienced, accurate and tested shooters. Testing is required for commercial harvesting in all jurisdictions, and for damage mitigation shooting on rural properties in the ACT. As required by codes of practice, only high-velocity ammunition is used, rendering the animal instantly unconscious and brain-dead. Kangaroos are stationary when shot. Pouch young are present all year in eastern grey kangaroo populations, and therefore must also be humanely killed by the shooter. Codes of practice provide for rapid destruction of the cranium which is humane, however the violence involved in achieving this is frequently mistaken for suffering and cruelty. Humaneness is dealt with comprehensively in Section 4.4 of the ACT Kangaroo Management Plan. Illegal shooting by untested and untrained people using inadequate equipment is a different matter. In the ACT any such act is liable to prosecution under both the nature conservation and animal welfare laws.

Please refer to the ACT Kangaroo Management Plan for more detail on all the issues summarised above. The Plan contains references to hundreds of scientific publications underlying its policies and a helpful glossary of terms.