AFRICAN wild dogs, already seriously endangered, are facing a further threat
from unnaturally high populations of lions, warn zoologists working in South
Africa鈥檚 Kruger National Park. The choicest habitats, with the largest numbers
of the dogs鈥� favourite prey, are so overrun with lions that the dogs are afraid
to hunt there.
Given the popularity of lions with the tourists who visit the Kruger and
other national parks, the scientists say there is an urgent need to establish
packs in areas that are free of lions.
Despite legal protection, the number of wild dogs across Africa is down to
around 5000 and falling. People are their worst enemies, followed by lions. But
high numbers of spotted hyenas, which steal food from wild dogs, can add to
their troubles. 鈥淟ions and hyenas may inhibit the recovery of wild dog
populations,鈥� says Martyn Gorman of the University of Aberdeen.
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Earlier studies of wild dogs suggested that their numbers depend largely on
how plentiful their prey is. But in the latest issue of Conservation
Biology (vol 11, p 1397), Gorman and Michael Mills of South Africa鈥檚
National Parks Board report that, in the Kruger park, this isn鈥檛 the case.
Kruger is home to around 400 animals, the largest surviving population of wild
dogs, but Mills and Gorman have shown that there are enough impala and
kudu鈥攖heir favourite prey鈥攖o support many more.
In an attempt to discover what was keeping the number of dogs low, the
researchers tracked eight packs, recording their numbers, their preferred
habitats and the abundance of their prey. They were surprised to find that the
places with the most impala and kudu had the fewest dogs. 鈥淚t was quite
unexpected,鈥� says Gorman.
The dogs鈥� problem is that the areas with most impala are also well stocked
with zebra, buffalo and wildebeest, the favourite prey of lions. Wild dogs avoid
lions, which kill both pups and adults. Lions account for 39 per cent of the
natural deaths of pups and 43 per cent of natural adult mortality. 鈥淚f you play
back tapes of lions roaring, the wild dogs scarper,鈥� says Rosie Woodroffe of the
University of Cambridge and author of the World Conservation Union鈥檚 Wild
Dog Action Plan.
Since the 1930s, the management of the Kruger park has favoured lions and
spotted hyenas. Provision of artificial water holes led to a buildup of large
herbivores, soon followed by a proliferation of lions and spotted hyenas.
Smaller carnivores, such as cheetahs, brown hyenas and wild dogs, have lost out.
The brown hyena, a daintier and more solitary animal than its spotted relative,
no longer breeds in the park.
Gorman and Mills suggest that restoring natural water supplies might help to
redress the balance. But such a move is likely to meet strong resistance. 鈥淭here
is no way a national park can control lions and hyenas to benefit wild dogs,鈥�
says Woodroffe. 鈥淭he lions are real moneyspinners.鈥�
Gorman agrees that parks must pay their way, but argues that it is not a
park鈥檚 job to maintain one species at the expense of another. 鈥淢y feeling is
that in a national park you should be maintaining a natural ecosystem,鈥� he
says.
However, Gorman鈥檚 main hope rests on establishing new dog packs on protected
land, where they won鈥檛 be plagued by lions and hyenas. Some of the game ranches
now being set up for sport shooting in South Africa and Zimbabwe would be ideal,
he says.