Culling of eastern grey kangaroos has always been contentious. Since white settlement their numbers have increased dramatically thanks to improved pasture, the provision of dams and waterholes for livestock, and the removal of any possible predators. In many areas they are now at the point where they need to be culled to prevent them destroying their own habitat. The situation is worse when they are confined to fenced reserves where they breed unchecked with no opportunity for youngsters to disperse. I suppose we could just leave them be, which would more closely mimic their natural boom and bust cycle. In this scenario numbers build up until they get beyond the carrying capacity of the land. The population then crashes with large numbers of animals dying from starvation, malnutrition and diseases such as lumpy jaw and hookworm infection. As a veterinarian that does not sound particularly humane to me and it also impacts, not just the vegetation, but all the other animals that share their environment with the kangaroos. This occurred some years ago when a reserve in Victoria was denied culling permission. The vegetation suffered badly and all the eastern barred bandicoots, an endangered species that had been introduced to the reserve, perished as a result.
While culling is not a particularly pleasant option it is surely better than letting them starve to death. All fenced reserves need to develop a comprehensive management plan that involves reducing numbers to their optimum stocking density followed by reproductive manipulation through castration, vasectomies and contraceptive implants. In this way culling would not be used as an ongoing management tool but only to deal with a problem that has been allowed to get out of hand.
I am convinced that much of the opposition to culling is because kangaroos, like their arboreal brethren the koalas, are cute. Many years ago koalas were introduced to Kangaroo Island. Given that an island is similar to a fenced reserve with no predators and no opportunity for dispersal the koalas ate themselves out of house and home. Culling would have solved the problem caused by this introduced species destroying its environment, but they were far too cute for that. If the island had been overrun by tiger snakes instead I’m sure no one would have raised so much as a whisper at the suggestion of culling.
The greatest tragedy, however, is that when a kangaroo cull is approved the shot animals must be buried and cannot be used for human or even animal consumption. While over 90% of Australia’s woodlands have been cleared, mostly for cattle and sheep production, a readily available resource is squandered. Not only is kangaroo meat lean and healthy but the animals themselves have a much smaller environmental impact than their cloven hooved brethren, with their methane breath and destructive feet. Why not use the resource that is already there, instead of importing thousands of ferals to further abuse an already damaged environment?
Dr. F. Bunny