CANDABA, Pampanga - Black-crowned night herons take off to roost at sunrise as the day shift arrives for a feeding frenzy at the Candaba marsh in the Philippines.
Thirty years ago the marshes covered some 32,000 hectares (79,000 acres) but thanks to the spread of agriculture and urbanisation just 72 hectares remain.
Today, ornithologists count some 12,000 birds a day -- a fraction of the number three decades ago.
"In the 1980s they would routinely count 100,000 wild Philippine ducks and mainland Asian garganays (wild ducks) in one day, just for the two species," said Michael Lu, president of Wild Bird Club of the Philippines.
Among the 50 or so wetland areas in the Philippines, the Candaba swamps -- covered in reeds and water hyacinths and bisected by high earthen levees -- are a key staging ground for birds ranging from huge purple herons to tiny Arctic warblers that return to continental Asia in the spring.
They had flown several thousand kilometres (miles) south months earlier, just before the winter.
But as the swamp has shrunk so too of course has the supply of fish, snails, insects and other food. What remains is hemmed in by rice paddies and communities that raise hogs and domesticated ducks.
The honking transients jostle each other on a huge fishpond owned by Candaba town mayor Jerry Pelayo, who has earned his environmental spurs by setting aside half the property for the seasonal visitors.
"This is the only place that remains as habitat for the birds," said Carmela Espanola, a wildlife biologist for the University of the Philippines.
"A lot of the wetlands are under threat because people keep reclaiming them," Lu said.
Since the area is all titled property, if owners drain the swamp the habitat would disappear and there is nothing the government could do, Lu said.
The Philippines situation is also unique in that a lot of people still hunt wild birds, Lu said.
Candaba farmhand August Sombillo used to belong to these ranks.
The 38-year-old father of six told AFP he used to hunt snipes that strayed into the six hectares of rice paddies he tends nearby. The great winter migration coincides with the only time of the year that the marshwater ebbs low enough to allow rice planting.
The meat of the pointy-beaked wading birds was a key protein source for his family who subsist on his annual share of the grain produce that adds up to less than 100 bags of unmilled rice.
But the mayor has banned the trapping of birds, unilaterally declaring the marsh a protected area and asking restaurants in surrounding towns to stop serving wildlife dishes.
Pelayo said he has also asked hog farmers upstream not to dispose of pig waste in streams that empty into the swamp.
The environment department, which conducts an annual census here, said there had been some good news with the endangered black-faced spoonbill and the rarely seen pied avocet returning this year after a three-year absence.
However the main trend is toward a decline.
"The big ones like the spot-billed pelican used to come here in Candaba," Espanola told AFP. "There used to be cranes and woolly-necked storks, but they have been extirpated in the Philippines."
The decline mirrors the status of birds endemic to the country -- of the 593 birds found in the Philippines, 181 are indigenous. Of these, 25 are considered endangered, half of them critically.