One of the great spectacles of Africa — the vast flocks of flamingos feeding at Lake Nakuru in Kenya — is under threat because silt from farming is choking the habitat, wildlife experts said on Thursday.
The lake, home to more than 1,5-million of the birds, has shrunk drastically in the past 30 years and is at risk of disappearing, according to the Kenya Wildlife Service.
The brackish Rift Valley lake, 144km north of Nairobi, has come under threat as nearby forests have been cleared to make way for farmland to feed Kenya’s growing population.
Rivers flowing into Nakuru from the surrounding hills bring a tide of soil, logs and branches — silting up the lake and blocking sunlight from its vegetation.
The silt threatens the growth of the blue-green spirulina algae on which the flamingos feed. Sewage from the rapidly growing town on the shores of the lake has also been blamed for flamingo deaths.
Since the 1970s, the shallow alkaline lake has gradually shrunk from 29,6sq km to less than 17,6sq km, and could vanish entirely, said Joseph Warutere, a senior wildlife warden.
”The silt is what is choking the lake,” he told the Nation newspaper. ”It is worrisome and if this goes on unchecked, we will have no lake in a generation to come.”
Nakuru, Africa’s first bird sanctuary, was established in 1960 with the specific purpose of protecting the flamingo. It provides a stopover on their migratory route from north-east Africa to southern Africa and also serves as a permanent home for many birds.
The lake, and neighbouring Lake Bogoria, have the world’s highest density of flamingos.
The population was once thought to be as high as two million, and 450 other bird species have been recorded at the lake. But the wildlife has repeatedly come under threat from effluent washed into the water from the town of Nakuru and hundreds of surrounding farms.
Mass deaths of flamingos in recent years have been blamed on changes in the chemical balance of the lake, which has led to a growth in toxins in the water.
Four years ago 40 000 flamingos died, and in 1993 a similar number perished in three months.
Analysis of flamingo carcasses found traces of arsenic and mercury which were linked to the effluent from local factories.
Lake Nakuru’s level has fluctuated dramatically in the past, and changes to the ecosystem caused by rising or falling water levels have dispersed many of the flamingos to other lakes in the Rift Valley.
Wildlife officials have been trying to raise awareness among local people of the threat to the lake.
While Kenyans are conscious of the value of their extraordinarily diverse environment — not least in attracting tourists — the pressing need to feed the population and develop industry often takes precedence.
”We are trying to instil a sense of ownership,” said Mr Warutere. ”People will try to protect what they own.” – Guardian Unlimited Â