Philippine eagles’ sex hormones rage with the rains

Apparently, the rainy season is also bed weather for the Philippine Eagle.

The onset of the season marked an unexpected start in the mating time of the country’s beloved species, one of the most critically endangered in the world and now being bred in conservation facilities.

Keepers at the Philippine Eagle Center in Davao City were surprised to hear mating calls among its denizens in May, or two months ahead of the usual start of the breeding season, according to Tatit Quiblat, development manager of the Philippine Eagle Foundation (PEF).

It was an early beginning of a behavior guided by the weather, Quiblat told the
Inquirer on the sidelines of a conservation forum in Ortigas Center yesterday.

And with the skies giving erratic signals, the eagles are getting confused as well, she said.

Sex vocals

“Normally, they start breeding behavior in July or August. But we started hearing—we call it sex vocals—in May. It is how they attract [mates], a signal to copulate,” Quiblat said.

“I can’t categorically say that it’s caused by climate change. But the difference in weather patterns has already affected the eagles. You can just imagine the effects on other animals, and on the plants and trees,” she said.

PEF has some 35 eagles under its care in the Davao facility, a number of them bred in captivity since efforts were made to hatch eagles 19 years ago.

“They haven’t bred yet [lately], but the behavior started showing much earlier. Our keepers were asking: ‘Wait a minute, was that a sex vocal?’” Quiblat said with a chuckle.

PEF estimates that there are some 400 pairs of Philippine eagles in the wild, based on known habitats around Luzon, Samar, Leyte, Davao and other parts of Mindanao, she said.

King of the wild

The Philippine eagle is considered “king” of the Philippine wild and is known globally as one of the most powerful raptors. Conservation groups are working to preserve the endangered species, battling the constant depletion of forests to protect their habitat.

A pair of eagles needs at least 7,000 hectares of forest to survive, Quiblat said.

But the Philippines loses up to 270,000 hectares of forest a year, based on a study of the United Nations Food and Agriculture Organization from 1990 to 2000.

Quiblat noted that the changing weather could also disrupt the food chain in eagle habitats, with their prey also making do with limited food.

“If our forests are unhealthy, meaning small animal populations are suffering, the eagle can’t find enough food, so he has to go [beyond] his normal territory just to look for food. This leads eagles to populated areas, which puts them at risk,” she said.

Increased awareness

But there’s a silver lining, according to Quiblat: PEF has observed an increased awareness of the Philippine eagle and its place in the local fauna.

She said more people were reporting incidents of eagles being captured or hurt.

PEF rescued four eagles on the basis of local reports from December 2010 to April—twice the annual average number for the foundation.

“That’s one of the highest rates in a given time,” Quiblat said. “Before, the foundation will get reports of eagles being held, and we rescue two birds a year.”

Aside from breeding birds at the eagle center, PEF is also at the “experimental stage” of releasing its captivity-bred eagles back into the wild, Quiblat said.

Community participation is urgent. Thus, the Department of Environment and Natural Resources’ Protected Areas and Wildlife Bureau yesterday gathered nongovernment organizations, corporate foundations and other private-sector partners at a forum to encourage more partnerships in conserving threatened species.