Myths and Realities
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 (PDF 6.8MB) contains factual explanations for many misconceptions.
Kangaroos control their own fertility and do not produce any more young than the environment will support.
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.
Kangaroos give birth continuously in every season.
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.
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.
The ACT has about the same number of kangaroos per square kilometre as NSW.
Eastern grey kangaroos are widespread and abundant in the ACT with some of the highest population densities recorded in south-eastern Australia. A survey in three ACT reserves between 2001 and 2003 found densities in grasslands of between 450 -510 per km2, among the highest recorded in Australia and; kangaroo density was 560 per km2, on one site, prior to a kangaroo cull in 2008. Densities in ACT reserves are considerably higher than: on ACT rural leases where culling occurs; and in rural land in NSW surrounding ACT, where kangaroo density was estimated at 12 and 14 per km2 in 2003 and 2006. 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 3.2 and Appendix 6 of the ACT Kangaroo Management Plan (PDF 6.8MB).
Kangaroos cannot eat themselves out of food.
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 (PDF 6.8MB).
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.
Kangaroos move to where there is food.
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 (PDF 6.8MB).
One native species (such as kangaroos) cannot harm another native species.
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 (PDF 6.8MB) covers this issue in section 1.4.1 and Section 3.8.4.
Grassland Earless Dragon in Tussock
Eastern grey kangaroos are facing extinction.
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 (PDF 6.8MB) summarise the state of knowledge and contested views, with further details in Sections 3.1.1 and 6.6.
Fertility control should be used instead of lethal methods.
As yet, there is no form of kangaroo fertility control applicable to free ranging wild populations. The ACT Government has been actively exploring long-term solutions to kangaroo over-population and overgrazing for some time. ACT is the only state or territory which has funded research into kangaroo fertility control and have done so since 1998.
Work is currently being undertaken with the CSIRO through the Invasive Animals Cooperative Research Centre. A successful injected vaccine has blocked fertility of all treated kangaroos for three breeding seasons to date. This work is still in the scientific research stage and due to the drug’s administration via injection, it is only suitable for small captive populations. The next stage is to develop an orally deliverable application which can be administered to wild populations. Funding and in-kind support through ACT Government ecologists is provided to 2016-17 to continue the research.
Refer to Section 4.6.2 of the ACT Kangaroo Management Plan (PDF 6.8MB) for a full explanation.
All kangaroo shooting is inhumane.
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. 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 nature conservation and animal welfare laws. As required by the relevant Code of Practice, only high-velocity ammunition is used by licensed shooters, rendering the animal instantly unconscious and brain-dead. Kangaroos are stationary when shot.
Local research has demonstrated that eastern grey kangaroos have a strong seasonal breeding pattern with the majority of young born at a similar time of the year. To minimise the chance of orphaning dependent joeys and young-at-foot, any culling of female kangaroos is restricted to the period between 1 March and 31 July. This is designed to avoid the time when most females have large pouch young or young-at-foot that are dependent on milk. Pouch young are euthanised in accordance with the National Code of Practice. The majority of pouch young likely to be encountered will be small and unfurred, lacking a fully developed nervous system.
Please refer to the ACT Kangaroo Management Plan (PDF 6.8MB) 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.