Most Land Environments Have Lost Large Animals
Large mammals have retreated from four-fifths of the earth's landscape during the last five hundred years.
This conclusion comes from researchers who compared maps of where mammals roamed in 1500 AD with where they live nowadays.
In the process, their study identified 108 sites on the planet that have retained a full complement of mega-fauna.
What's kept animals alive at these locations is either they're intensively managed for nature conservation, had few large mammal species to begin with, or are too remote and inhospitable for people.
Altogether the refuges total 27 million square kilometres (10.4 million square miles), comprising 21 percent of the land area historically occupied by big beasts. The sites vary in size from 7 million square kilometres in Siberia down to the 24 square-kilometre Bawean Island of Indonesia.
The majority of land that hasn't lost any mammal species of over 20 kilograms (44 pounds) in size lies in six large areas: northeastern Canada, Siberia, the Himalayas, central Australia, the Amazon - Orinoco basins, and west-central Africa including the Congo basin.
The region with the least amount of historic habitat remaining fully occupied by big mammals is southern Asia, including India, Malaysia, Philippines and most of Indonesia, with 1 percent of the area left in ten tiny locations.
Most of the wildlife havens support fewer than eight different species of large mammals. The richest sites, harbouring 30 or more species, lie in the Himalayas and sub-Saharan Africa. Generally these areas with a wealth of diversity are well protected. Globally though, 12 percent of the land retaining its full suite of large mammals has some type of formal protection.
Close to three-quarters of the land that large mammals have vacated in the last five centuries was once occupied by one or more of the 20 species that have undergone the most massive contractions in their range. These include bison and wolves in North America, jaguars in South America, elephants and giraffes in Africa, and horses in Eurasia. Additionally, over one-third of the 262 animals studied have lost at least half their former range.
John C. Morrison, Wes Sechrest, Eric Dinerstein, David S. Wilcove and John F. Lamoreux. 2007. Persistence of Large Mammal Faunas as Indicators of Global Human Impacts. Journal of Mammalogy. 88(6): 1363-1380.