Wild animals compete with cattle for food and require land which could otherwise be used for agricultural purposes. When large areas of hitherto virgin territory are divided and developed into an intricate pattern of human use, or when protection of animals in parks or reserves results in great population increases amongst such animal species, then wild animals are likely to conflict with human activities. Wild animals may cause damage to crops and farm animals when agricultural land borders on virgin territory or game reserves. In addition, wild animals may bring disease into valuable domestic herds.
In Africa, for example, the main animal which causes damage is the baboon. In some African regions, other animals such as queleas, starlings, bush pigs, monkeys, cane rats or elephants, become local problems; and wild dogs, hyenas, jackals, lions and leopards also cause problems. Control of these animals is sometimes difficult and always delicate; destruction of predators, for example, upsets the predator/prey cycle and often leads to great increases of other pest species. Destruction of leopards leads to overpopulation of baboons and an increase in rodent populations. In Botswana, increases in numbers of plague-carrying jerbils in desert areas may have resulted from the overhunting of small carnivores. An adult elephant eats 660 lbs of fodder a day so that large herds can devastate several square miles of country in a day, destroying the habitats of other species. In order to keep wild animals from domestic animals, programmes for shooting out wildlife or fencing off huge areas have taken place in many parts of Africa. Fences in particular are very expensive to erect, they decimate animal populations whose migration routes they cross, and they are fairly quickly damaged.
In 1997, without any natural enemies to keep them in check as on other continents, perhaps 12 million wild cats in Australia were killing small creatures whose evolution has not taught them that cats are their enemy. Domestic cats each kill an estimated 25 native animals a year, and wild cats kill as many as 1,000 a year, according to the National Parks and Wildlife Service. Cats were responsible for 39 species being either extinct or living only in zoos in Australia. These include the pig-footed bandicoot, the brush-tailed bettong, the rufous harewallaby and a dozen other birds and marsupial species that were found nowhere else on earth. Scores of other species are endangered, including woylies, boodies, numbats and the potoroo.
In 1930 in southern Pri-Balkhash, in the region of Krasnyi town, tigers destroyed in a short period over 200 head of cattle, forcing the local populace in several places to migrate with their livestock to safer regions.