I post this on behalf of Mike Lodge
THE PELICAN CHALLENGE ON THE WEST COAST
by Mike Lodge
The near-threatened Great White Pelican (Pelecanus onocrotalus
) is arguably the largest fish-eating seabird endemic to the South African West Coast. It can be recognised in flight by its huge wingspan, S-shaped neck, long beak, its penchant for soaring in thermals and for flying in formation. Some call it the Jumbo Jet of the birds.
Photo courtesy of UCT's Avian Demography Unit, taken by René Navarro
A number of years ago, a pig farm near Cape Town started feeding their pigs chicken carcasses. These were gutted before feeding and the offal was thrown into a hole in a remote corner of the farm. Before long, various scavenging birds, amongst them the Great White Pelican, started eating this regularly supplied and nutritious food. Unfortunately, as we all know, most chickens battery-reared today are fed growth hormones, and it is suspected that this has had an effect on these pelicans.
It is postulated that this plentiful supply of hormone-enriched feed caused the pelicans to breed better than is usual, and their offspring went to eat where their parents took them –to the pig farm. Furthermore, it was believed that they never learned that their waterproof feathers, long beak and gular pouch were so ideally suited to bulk fishing in the sea, for here were easy pickings on land. Today, a whole generation of pelicans has grown up with no knowledge of fishing techniques, or even what a fish is, or looks like.
When the authorities finally realised what was happening on the pig farm, they intervened and closed up the offal hole, effectively cutting off this bountiful food supply. After some initial confusion during which some of these birds died from starvation, the remaining pelicans started looking for alternative food sources, by seeking in an ever-widening search pattern. After some time, they found that some unpopulated, predator free islands in the mouth of the Langebaan lagoon just outside Saldanha Bay had thousands of defenseless gannet, cormorant, penguin, oystercatcher and gull nests, ripe for easy pickings. These hungry pelicans waddled through the breeding colonies, scared the resident parent birds away with their daunting size, and swallowed every egg and chick they could find, in many cases, decimating local populations of our endemic sea birds. The Jumbo Jet of the birds had become the Jumbo Vacuum Cleaner. The 2006/7 breeding season yielded a virtually zero production of hatchlings to complement the West Coast seabird population.
Painting by Mrs. Binks MacKenzie
These pelicans cannot be shot as the species is listed as “near-threatened” in the Red Data Book, and besides, there is no way one can identify an ex-pig farm bird from a normal one at a distance. They cannot be poisoned without serious risk to other life forms. In the meantime, these birds are breeding, and passing on their bad feeding habits in turn to their fledglings, thereby exacerbating the problem.
As the islands are part of the proclaimed West Coast National Park, the SANParks Honorary Rangers (HRs) have teamed up with Park permanent staff under the watchful eye of avian scientists at the University of Cape Town. The idea was to create a rotating presence on these exposed and wind-swept islands during this year’s seabird breeding season (October to January), in order to scare off pelicans whenever they land. This is a lonely, risky and labour-intensive operation entailing much scrambling over rocks and climbing to high ground to watch, and down again to chase, followed by more climbing. The teams operate in 5-day shifts on the two bigger islands, Jutten and Malgas. Their day starts at first light (05h00) when the pelicans arrive and ends at sunset (20h30) when they leave to roost on the mainland.
The idea is that each island is divided in two, with one half being left to the pelicans to carry on with their bad habits, while the other half is considered as a “pelican-free” zone and the birds are actively chased from these parts of the islands. This effectively provides comparative zones on each island, where one is a control zone showing what happens if we do nothing, while the other indicates the results of the chasing operation. A weekly, and in some cases, daily breeding success count is maintained by the HRs on the islands, as well as other possible sources of predation such as Cape (Kelp) Gulls and Cape Fur Seals, so that the bird scientists can assess the impact that chasing has had on the pelican predation and then use this data to make a decision on the way forward for next year’s breeding season.
Once again, man’s thoughtless actions have initiated a complex web of change that is not easily unraveled. We already know that an unthinking motorist throwing an apple to a baboon at a lay-by to impress his child is signing the death warrant of that animal, for the day will most certainly come when that animal will be shot by other folk who are sick and tired of the marauding baboons who have become used to free food as supplied by other thoughtless humans. A life lesson for the reader is not to ever feed a wild animal, no matter how “sorry” we feel for it or how cute it is. We don’t realise the longer-term implications of such acts, and in many cases, what starts out as an innocent attempt to supply a perceived shortage of food, results in an unforeseen catastrophe later.
So what is the long-term answer? Everyone is feverishly working on a solution, and the island teams are chasing pelicans from the pelican-free zones and gathering important field data during their shifts on the islands, but in the meantime, our coastal bird populations are under serious threat. Bird scientists are hoping that the pelicans will get the message to stay off the islands, and scientists are happy to report that some pelicans chased from the islands have been spotted catching fish in the sea. However, it remains to be seen if they can all switch to this sole method of sustenance and desist from pillaging the seabird populations on the islands into the future.
West Coast National Park