In India, Nets Save Baby Storks From Falls
for National Geographic News
|July 23, 2002|
Conservationists in the remote forests of northeastern India have come
up with an ingeniousand inexpensiveway to save baby storks:
Greater adjutant storks, Leptoptilos dubius, build their nests high on the limbs of the majestic silk cotton tree. But in recent years, a growing number of hatchlings have been falling out of the nests. If the 65 to 100 foot (20 to 30 meter) fall doesn't kill the birds, their injuries leave them prey to dogs and crows.
There are only about 1,000 greater adjutant storks left in the world, and about 80 percent of them are in the Indian state of Assam. Scientists are afraid the death toll from plunging out of nests could seriously impair the species' battle against extinction.
The World Conservation Union classifies the greater adjutant stork as a "conservation-dependent" species in great danger of extinction.
"Greater adjutant storks are a highly endangered species that requires complete protection wherever it occurs, in breeding and non-breeding periods," said Asad R. Rahmani, chief of the Bombay Natural History Society in Mumbai, India.
When the Bough Breaks
Deforestation is seen as the major culprit in the wave of deaths of tumbling storks.
The storks tend to nest in communities; a single tree might host ten or more nests. But fewer trees means fewer nesting spots, forcing the storks to build their nests on thinner, less viable branches.
The branches can withstand the weight of the birds while the hatchlings are small. But as the young chicks grow, their increased weight combined with the impact created when both adults return to the nest after foraging for food can cause the tree branches to break or splinter, and send the nest crashing to the ground.
Even when nesting branches are sufficiently sturdy, the decline in tree cover means that the nests are more vulnerable to storms and high winds that can toss young storks out of their nests, experts say.
The Indian state of Assam is home to about 850 greater adjutant storks, according to Prashanta Kumar Saikia, a zoologist at Gauhati University.
The original idea for stork safety nets evolved in a little-known township of Assam called Nagaon. Deeply concerned about the death toll, Srimanta Goswami, a local wildlife lover and member of the Green Guard Nature Organization, joined with volunteers from Aaranyak (which means "of the forest") to find a way to save the storks.
Unable to prevent the falls, they came up with the idea of tying safety nets around the tree trunks. The baby storks would still fall, but the nets would keep them from being killed.
The Wildlife Trust of India (WTI), a volunteer organization based in New Delhi, stepped in to provide funding.
The birds' breeding season extends from October to April; the first nets were installed in September 2000 in two nesting colonies in Khutikhatia and North Haibargaon.
The nets, made of thick nylon lined with soft muslin cloth, protected 42 nests in 10 silk cotton trees. Each nest usually has two to four chicks.
"There are just a few nesting sites of this beautiful bird that remain active, and just these 42 nests account for about 80 percent of the breeding population of the bird in Assam," said Khalid Sayeed Pasha, a conservation biologist with WTI.
"The nets worked like magic," said Pasha. During the 2000 to 2001 breeding season, 21 chicks were rescued.
Whenever possible, the chicks are returned to the nests of their parents, which seem to accept the return of their young without a fuss. Because the storks frequently nest in communities, however, it is sometimes difficult to determine which nest the chicks fell from. In such cases, the young storks are hand-reared.
Chicks are also hand-reared if the entire nest was destroyed. Of the 21 chicks recovered in 2000 to 2001, 15 were returned to their parents and six had to be hand-reared in a bird rehabilitation center.
"The technique of raising fallen chicks is quite successful," said Rahmani.
Data on the initial results of the Assam project are currently being compiled. But the researchers involved are quite hopeful that the simple netting technique will be a first step toward increasing the overall numbers of the greater adjutant stork.
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