A new study conducted by the United Nations Environmental Program has found that Kenya's Masai Mara wildlife reserve has lost more than 50 percent of its large animals.  Conservationist says serious investment in the parks must be made to protect the park's animals from further decline.  

Populations of big game animals such as lions, zebra, and buffalo have fallen by an average of 59 percent since 1970, according to a recent joint survey of Africa's wildlife reserves.

The study, conducted by the United Nations Environmental Program, the Zoological Society of London and Cambridge University, highlights declining biodiversity across the continent.  It also urges major commitment to protect the animals, which draw tourists from around the world each year.   

The report lists people as one of the biggest threats to park wildlife.  Many of the continents national parks are surrounded by communities which alter the ecosystems through hunting, farming and grazing.

According to the author of the report, Ian Craigie, this problem is particularly relevant in Kenya's Masai Mara.  The world-famous reserve is home to one of the largest animal migrations on earth, during which thousands of wildebeest, gazelle and zebra move south, towards Tanzania.

The annual migration, while often hailed as one of the greatest national spectacles on earth, makes it difficult for rangers in the Masai Mara and the adjoining Serengeti in Tanzania to protect the wildlife.  Migrating wildlife often wander off of the reservations, exposing them to poachers and farmers protecting their crops.

The other major issue is money.  Africa's national parks and wildlife reserves have a combined area equal to nearly one-third of the United States.  According to Craigie, many of the parks simply do not have the resources to protect such large areas.

"All the parks are pretty much doing the best they can with the resources they have," he said. "Almost all of the parks outside southern Africa that we looked at are chronically under resourced.  They have not got enough staff; they have not got enough money; in a few cases, they have not got equipment or expertise as well.  A lot of these parks know they have got problems, and that things are not going as well as they would like.  They just have not got the capacity to fix them."

The population decline that has resulted from inadequate funding may create a potentially vicious cycle for the parks.

According to Craigie, reductions in the wildlife could result in a decline in the number of tourists who visit the parks.  Many of the parks rely on income from tourism to fund conservation efforts.  A decline in tourism could force the parks to work with even more limited resources to protect the wildlife.

The report found that West African parks were most in need of funds.  The survey observed an 85-percent decline in animal populations from 1970, compared to just over 50 percent in East Africa, a difference attributed primarily to financial difficulty.

But not all of the news was negative.  Among the study's highlights were the rebounding animal populations in southern Africa.

According the survey, the funding support and management techniques observed in the region could provide a model to reverse the trend on the rest of the continent and preserve Africa's biodiversity.