Robben Island in crisis
John Yeld, Daily News
April 30, 2008
Robben Island's natural environment is in a state of crisis, with animals like bontebok, springbok, fallow deer and rabbits starving to death because of a lack of vegetation on this important World Heritage Site.
Carcasses are lying in dry veld, where only inedible khakibos weeds are still thriving.
Although the island is always very dry at the end of summer, the problem is mainly the result of an explosion of the feral rabbit population which is eating everything in sight. A delay in reducing the number of fallow deer has also contributed to the problem.
Environmentalists are horrified by the state of affairs, and are blaming the island's managers - the Robben Island Museum - for the disaster because they allegedly ignored warnings about the ecological threat posed by the rabbits given to them at least three years ago.
Environmentalists warned the island's prestigious World Heritage Site status, previously threatened because of the poor environmental management, could again come under review.
Although some mammals have been removed during the past year, there is not enough suitable food on the island for those left behind. And while a rabbit culling programme was initiated, it was stopped - apparently because the contractor had not been paid.
Weird behaviour has been observed as starving animals attempt to reach every piece of available greenery.
The rabbits are climbing acacia thorn trees on the island and have been seen high up among the thorns, while a fallow deer was observed trying to feed off the carcass of a roadkill rabbit. Both rabbits and deer have been spotted feeding off kelp on the beach.
Estelle van der Merwe, who worked closely with the Robben Island authorities during the Treasure oil spill in 2000, said she was appalled by the situation.
"I have been going there since 1994 and I have never seen the island, and specifically the animals and the environment, in as bad a state as they are now," she said.
"There is very little groundcover left and parts of the island are extremely sandy. The buck are literally starving and have difficulty with access to water."
Van der Merwe said "the final straw" had been seeing springbok with their ribs "very clearly visible".
She said she intended contacting Deputy Minister of Environmental Affairs and Tourism Rejoice Mabudafhasi about the issue and would ask her to visit the island "as a matter of urgency".
Robben Island Museum falls under the Department of Arts and Culture. Prof Les Underhill, director of the Animal Demography Unit at the University of Cape Town whose students have done substantial research on the island's seabird population, is also very concerned.
Desert
"The carrying capacity of the island for grazers such as rabbits and fallow deer has been grossly exceeded this summer," he said. "The island looks like a desert, and rabbits have been feeding four metres above the ground, climbing in among the top branches of the trees.
"They have eaten the bark off trees, and it remains to be seen if they have effectively been ringbarked, and will die. A fallow deer, which is primarily a grazer, has been observed eating the corpse of a rabbit.
"The island ecosystem has taken huge strain this summer, and the path to recovery looks more complex than simply the arrival of the winter rains."
The bontebok population, which is of great conservation value because it is a pure strain of this species uncontaminated by cross-breeding with closely-related blesbok, has been particularly hard hit and numbers have crashed.
A count in April last year revealed 80 individual bontebok. Fifty of these animals were removed in July, and during two separate counts in September, 21 bontebok were recorded, including five youngsters.
But last week just two could be found. Although the managers belatedly brought in some fodder for the mammals last week and have now also asked SA National Parks for assistance, this may be too late for the bontebok, which are exclusively grazers and do not take artificial feed.
The number of springbok has declined from a maximum of 42 in 2004 to 25 last year to just 12 this year, and the fallow deer population, which reached a maximum of 223 last year, is down to little more than 90 at present. Some of these deer were culled at the end of April, and visitors were appalled when bloody carcasses were loaded aboard a ferry in full view of tourists, some of whom took pictures or videos.
Rabbits were introduced to the island soon after Van Riebeeck landed at the Cape in 1658, and are considered part of its cultural-historical heritage. Their numbers were kept in check partly by the feral cat population, which also devastated seabird populations.
After substantial delays by management during which breeding by the seabirds - including threatened African Black Oystercatchers - was severely disrupted, a cat eradication programme was eventually instituted.
But it was stopped before all the cats were removed, reportedly because of funding problems, and there are at present still at least five left.
Underhill said it was "extremely disappointing" that there were still cats on the island. "Seabirds breed on islands to avoid predators. The Robben Island cats are the descendants of pets abandoned a long time ago, and they cause death and destruction for penguins, terns, oystercatchers and even to the island's chameleon population.
"We don't want to see more cats killed than is absolutely necessary, but this is an inevitable consequence of the island authorities' long drawn-out eradication operation."
Van der Merwe said conservationists wanted the island's managers to institute an immediate crisis plan for the remaining mammals on the island and to develop an environmental management plan to ensure their effective future management.
Robben Island Museum has been asked to respond.