October 27, 2018
A relocation programme spreads a rare subspecies to new habitats
TO A FOREIGN tourist, a giraffe is an extraordinary and elegant beast. To locals it is, too often, a larder on legs. A giraffe can weigh as much as a tonne and a half. Only two African animals, the elephant and the white rhino, are heavier. And bush meat fetches high prices. So, even though giraffe have no tusks to steal and their stubby horns, known as ossicones, command no premium in the market for Chinese folk medicine, poachers take a deadly interest in them. Add to that the effects of human encroachment on their habitat and the result is a rapid drop in population. According to a report published in 2016, by the International Union for Conservation of Nature, giraffe numbers fell from between 152,000 and 163,000 in 1985 to fewer than 98,000 in 2015.
Murchison Falls National Park, in Uganda, is home to about 1,250 of those that survive, but that 1.3% is disproportionately important because it constitutes three-quarters of the remaining population of a particular subspecies, Rothschild’s giraffe. In the view of conservationists, that is a lot of eggs in a single basket. Hence a project, begun in 2015 by the Ugandan Wildlife Authority and the Giraffe Conservation Foundation, a charity based in Namibia, to extract groups of these animals from the park and take them to places that look like prime giraffe habitat, but which currently have no giraffe in them.
Since the project began, four groups—of 15, 18, 19 and 14 animals—have been so moved, often to the bemusement of existing wildlife in the recipient areas, which take time to get used to the new neighbours. The first transfer was to Lake Mburo National Park, in western Uganda. The second and third were to the southern part of Murchison itself, across the Nile, which bisects the park and acts as a barrier to giraffe movements. The fourth batch was moved this August, to Kidepo Valley National Park in the north-east of the country.
During the second translocation from the north to the south of Murchison, in August 2017, new solar-powered trackers were fastened to the enforced migrants’ ossicones, so that their movements could be followed by satellite. But good old-fashioned fieldwork is involved, too. Michael Brown, a researcher at Dartmouth College in New Hampshire, has, over the past four years, photographed virtually all of the Rothschild’s giraffe living in Murchison. He has catalogued their distinctive markings, as unique to them as fingerprints are to people, using pattern-recognition software. That enables him to select known individuals and monitor their habits over extended periods.
Giraffe eat about 35kg a day of leaves from bushes and trees. To note these diets in detail, Mr Brown each morning picks an animal and follows it in a Land Cruiser for about 11 hours. While doing so he records where the animal goes, and what, when and how much it eats.
Most giraffe meals are mouthfuls of leaves stripped from branches by the animals’ prehensile lips and tough tongues, which are impervious to needle-sharp acacia thorns. By September 2018, Mr Brown had counted more than 155,000 of these browsings. He is trying to understand how the availability and distribution of different plants, of varying nutritional value, affects how giraffe forage and roam, both from day to day and from season to season. Such data will eventually assist in choosing where to dispatch each batch of emigrants from the park.
This dispersal of the Rothschild subspecies is made more urgent by a potential threat to the northern part of Murchison. Since 2012 Total, a French energy company, in partnership with the Chinese National Offshore Oil Corporation and Tullow Oil, a British firm, have been exploring there for petroleum. The consortium is now sinking test wells in promising locations to find out whether commercial exploitation is possible. How much giraffe and other animals in the park will be affected by the drilling, road construction and other development now under way is unclear. To help find out, Total began, in April of this year, paying for a project that radio-collars various species, including giraffe, lions, antelopes and hyenas, in order to study how oil-related activity is disrupting their movements, behaviour and levels of stress.
Murchison may well contain workable oil deposits. Data from this new study may guide the details of that exploitation, to minimise its impact on wildlife. Meanwhile, the transplants to Lake Mburo and the southern part of Murchison seem to have worked. The newcomers are breeding. The eggs, as it were, are now in multiple baskets.