Watch an endangered eagle chick grow up in rare video

The Bagobo Tagabawa people, who live at the foot of Mount Apo in the Philippines, tell the story of a banog, or great eagle, that snatched a man and carried him away to its aerie. The banog had an eaglet, and that eaglet befriended the man. When the it grew up, it freed the man, returning him to the village the same way he’d come. The man named his son, who founded the first Bagobo Tagabawa villages, after the young banog out of gratitude—the title Datu Banog is still given to leaders of exceptional courage and wisdom.

Today, the Philippine eagle, one of the largest eagle species in the world, is better known for its ability to carry off monkeys as prey. But despite its status as the national bird and its moniker of king bird, or haring ibon in Filipino, the Philippine eagle’s relationship with people is fraught. Because of hunting and deforestation, the eagles have become critically endangered.

Philippine eagles are found on four of the more than 6,000 islands in the Philippines: Luzon, Samar, Leyte, and Mindanao. Their preferred habitats include primary forests in the lowlands and at mid-elevation, much of which has been cleared for development and logging, driving many eagles farther into the mountains. Since the start of the 20th century, the Philippines has lost almost 75 percent of its forests. The giant tropical hardwood trees that the eagles nest in are prized among illegal loggers for their lumber.

Most of what we know about the eagles comes from studying eagle populations on Mindanao, in captivity or at known nesting sites, says Jayson Ibañez, research and conservation director at the Philippine Eagle Foundation in Davao City. The Philippine Eagle Foundation was formed in 1987 to conserve eagles through captive breeding and has since expanded its mission to include scientific research, educational outreach, and culture-based resource management programs. Population figures—extrapolated based on the average distance between known nesting sites—are estimated at about 400 pairs, Ibañez says.

Philippine eagles, which weigh about 10 to 18 pounds and have wingspans averaging 6.5 feet, are excellent fliers. They propel themselves into the air with a few power flaps and then glide, Ibañez says. They ride on thermals, rising currents of hot air, then slowly spiral back to the earth.

Philippine eagles also excel at staying hidden, making them difficult to study, says Camille Concepcion, faculty instructor of biology and ecology at Mindanao State University. The eagles are most noticeable during courtship and mating seasons, when they perform special calls and flight displays. They even briefly clasp claws mid-air, though not in the thrill-seeking manner of bald eagles, which lock talons and plunge in a death spiral toward the ground before releasing each other as their preferred form of foreplay.

To seal the deal, male Philippine eagles present food and nesting materials to their females before mating. They maintain lifelong monogamous relationships and repeat this courtship display every time they breed, Concepcion says.

Female eagles usually lay one egg every two years, which they incubate for almost two months, with some assistance from their partners. After the chick hatches, the male eagle initially does most of the hunting while the mother does most of the feeding. Philippine eagles eat a range of animals, including macaques, palm civets, flying squirrels, bats, birds, snakes, and other reptiles. Flying lemurs seem to be a favorite, Ibañez says.

Juveniles stay with their parents until they’re about a year and a half old. Then, for the next four years, they strike out on their own, wandering from forest to forest and crossing open fields until they reach sexual maturity, when they find a mate and a place to settle down.

This often puts the eagles, which are capable of taking down chickens, small dogs, piglets, and even small goats, in conflict with farmers, Ibañez says.

That’s why the Philippine Eagle Foundation’s conservation plan includes programs to improve the economic opportunities for farmers and indigenous people so that they don’t have to choose between protecting their meager livelihoods and conserving the eagles, Ibañez says. For example, the foundation teaches farmers to restore habitat through agroforestry or to work as forest guards against poaching and logging.

There’s still a lot we don’t know about Philippine eagles, including how long they live in the wild, their exact population numbers, where they go as juveniles, how they use their habitat, and how populations differ from island to island. Even with GPS tracking, which the foundation started to use on rehabilitated eagles, the battery is only good for about three years.

Local engagement gives the researchers an extra pair of eyes on the ground, even in remote areas, Ibañez says. Eagles are loyal to the places where they breed and return to the same nesting areas year after year.

“It’s important that Philippine eagles are seen as Philippine citizens, too,” he says. “They’re really one of our world’s unique jewels.”