Patrols in Tanzanian park slash poaching-scientists
George Obulutsa, Reuters
November 23, 2006
DAR ES SALAAM, Nov 23 (Reuters) - Patrols in Tanzania's Serengeti National Park have cut poaching and increased the population of black rhinoceros, elephants and buffalo, a paper to be published on Friday in Science magazine shows.
The 14,763 Sq Km Serengeti National Park is famous for its 1.5 million-plus annual animal migration to and from Maasai Mara in Kenya.
Ray Hilborn, an aquatic and fishery sciences professor, and his six co-authors show that elephant, buffalo and rhinoceros herds declined in the park after 1977, when most of Tanzania's economy was closed to the world and spending on anti-poaching patrols was slashed.
In the late 1980s the situation improved and more money was allocated to protecting wildlife, leading to larger elephant, rhinoceros and buffalo herds.
"The animals are 'telling' us poaching is down now that there are 10 to 20 patrols a day compared to the mid-1980s when there might be 60 or fewer patrols a year," said Hilborn, a professor at University of Washington in the United States, in a statement ahead of the paper's publication.
The increase in animal numbers can be measured using aerial surveys, he said.
Since poaching is illegal, determining the number of animals killed is impossible, the statement adds.
POPULATIONS REBUILD
Hilborn and his colleagues used a technique employed for decades to estimate fish abundance and set fishing limits - catch-per-unit-of-effort. This compared the number of fish caught in an area to the time spent fishing by all vessels.
When adapted to poaching, they divided the number of poacher arrests with the number of patrols in Serengeti. Anti-poaching effort was measured as the number of daily ranger patrols.
They assumed other factors like patrol officer training did not affect the arrests, and the number of poachers caught per patrol showed the intensity of poaching.
Serengeti park authorities have recorded poacher arrests since 1957. The paper said the data showed that after 1977 poaching was widespread, cutting buffalo, elephant and rhinoceros numbers. But after 1993, poaching fell low enough to allow population resurgence.
For instance, the number of buffalo fell to just over 40,000 in 1985 from about 70,000 in 1975. Buffalo population fell further in 1993 when drought killed 40 percent of them, but recovered after that.
"We show that the precipitous decline in enforcement in 1977 resulted in a large increase in poaching and decline of many species," Hilborn and his colleagues wrote.
"Conversely, expanded budgets and anti-poaching patrols since the mid-1980s have significantly reduced poaching and allowed populations of buffalo, elephants and rhinoceros to rebuild."
Other authors in the study are Peter Arcese and Anthony Sinclair of University of British Columbia in Canada, Markus Borner and Grant Hopcraft of the Frankfurt Zoological Society, Germany and Simon Mduma of Tanzania Wildlife Research Institute.
Others are Justin Hando and Martin Loibooki of Tanzania National Parks.