The red kangaroo breeds opportunistically in response to good climate conditions, and give birth in rapid succession. This mechanism enables the female to produce an independent offspring every 240 days under good conditions, although it takes 600 days for each offspring to develop from conception to independence. With the onset of drought and decline of food there is initially a heavy mortality of the young when they leave the pouch. If conditions are improved by rain then the young will survive. These nasty varments have frequently inflicted misery on settlers in inland Australia.
Population explosions follow periods of exceptionally good rains or floods.
The long-haired rat has an extrememly high reproductive rate and, when favorable conditions lead to anabundance of grass seeds and green plants, this potential is realized. As the country dries, most die and distribution returns to restricted small refuge areas where water and plant food is available even during droughts. Most effects, however, were not so good. Flash floods killed cattle and destroyed crops in Africa. Brushfires twice the size of England scorched remote portions of drought-stricken Australia.