PH eagles’ keepers called heroes of vanishing breed
DAVAO CITY—Unlike men, Philippine eagles are monogamous.
“Philippine eagles stand out from other birds because they are monogamous. They choose only one mate for life,” said Mario Entrolizo, keeper of six Philippine eagles and a dozen other raptors at the 8.4-hectare Philippine Eagle Center located at the far southwest of Davao’s city proper.
The foundation considers Entrolizo and its five other keepers heroes of the vanishing Philippine eagle along with its teams in the field, which are protecting the habitats of Philippine eagles in the wild.
The sanctuary is under the Philippine Eagle Foundation (PEF), a nongovernment organization on the front lines of the country’s forest conservation efforts since 1987.
Thirteen-year-old Mindanao, an offspring of two eagles captured in the wild, has found not just a keeper in Entrolizo but a surrogate mate and partner, who has been his caretaker since the day he was hatched.
He is the only person who can train the eagle to deliver sperm samples for the center’s artificial insemination program.
Mindanao would not copulate with another eagle since he had already become attached to Entrolizo and chosen him as his mate.
Odd as it may sound, there is a scientific explanation to that, according to PEF officials.
Through the process of sexual imprinting, the eagle chooses a keeper—even a human—as its mate, enabling PEF personnel to use the eagle’s semen samples for its breeding programs.
During the breeding season from June to January, Entrolizo, clad in a protective leather jacket and gloves, engages in courtship with his eagles. To Mindanao, the animal keeper is a female but to the other female eagles, he is a male.
Courtship, which includes bringing twigs and leaves to the eagle to make a nest, is part of a process called imprinting—a necessary component in artificial insemination.
Entrolizo would collect the semen from Mindanao and inseminate this into a female eagle.
How the eagles behave never fails to amuse Entrolizo.
He recounted one instance when he saw leaves neatly placed around a young eagle in the nest, apparently done by the parent to protect it from ants.
“You will also often see them leaving a portion of their food for me,” Entrolizo said.
The keeper spends almost an hour in the morning and in the afternoon to feed the eagle assigned to him, a job he cannot pass on to others.
“You have to be good to him all the time because he will never forget you if you have caused him harm,” said Entrolizo, 46, who has been an employee of PEF for nearly three decades now.
The PEF takes care of 35 Philippine eagles, most of which are bred in captivity.
One of them is iconic Pag-asa, the first Philippine eagle successfully hatched in captivity in 1991. Its only offspring Mabuhay, a product of artificial insemination last year, is also reared in one of the enclosures at the center.
The PEF employs a holistic approach in protecting the population of the eagle, a 0.9-meter-tall rainforest raptor looking so regal with its wingspan of 2.1 meters—the broadest in the world—and its blue-gray eyes.
It strives to protect the areas where these species live and, at the same time, makes sure that through its breeding center, they are saved from extinction in the event of a wild population crash.
“It is the largest predator we have. And over the years, it has become the symbol of Philippine wildlife conservation,” Dennis Salvador, executive director of PEF, told the Inquirer.
The Philippine eagle, locally known as “haribon,” has been the indicator of a forest’s health, being the largest predator in the Philippines’ ecosystem.
“By saving it, you provide an umbrella of protection for all other species living in the same habitat,” Salvador said.
According to records, the country has less than 400 pairs of Philippine eagles, with more than half of them found in Mindanao. Other forests in Sierra Madre in Luzon and in Samar and Leyte provinces in the Visayas are also known as hosts to the Philippine eagles.
But PEF officials said the number could be even less due to incidents of human persecution.
Raising the alarm
PEF has been raising the alarm on the dwindling number of Philippine eagles in the wild and humans are the ones to be blamed.
“Our data suggests more than 90 percent of juvenile eagles die before they reach maturity. A large part of this is caused by humans. Eagles were shot, trapped and hunted,” Salvador said.
On Aug. 14, a mother Philippine eagle being monitored by PEF was found decomposing some 10 kilometers away from its nesting site in Sitio Mitondo in Barangay Subulan, Davao City.
A crack at its keel bone indicated that the mother eagle had been shot. Officials of PEF suspected that the killing could be a result of the conflict between a tribal group and barangay officials in Sibulan, which has become a favorite spot of wild bird photographers.
Jayson Ybanez, research director of PEF, said their research team wanted to know how endangered the Philippine eagles are, as it was updating the current data on eagles by surveying the population.
One method it uses to track the movement of eagles from a distance is through telemetry.
A team, usually composed of a veterinarian, a biologist and volunteers, is tasked to watch the eagle for hours from the edge of a cliff with their field scopes.
The team sets up trapping sites in forests to capture Philippine eagles and attach transmitters to their bodies so it could track down their movements.
Ybanez said a pair of Philippine eagles would usually take 800 ha of forests as its nesting site, where they would keep its young, apart from its home range over which it can freely fly.
“Bringing them closer to humans is dangerous for them,” he said.
Some eagles are forced to fly out of their home range, mainly because of the presence of humans in the areas, he said.
Salvador said that apart from the fact that a pair of eagles lays one egg per nesting cycle and it takes the young 17 months to fledge from the nest, preserving their habitat is a major challenge.
Roughly 90 percent of Philippine forests have been denuded due to human activities, Salvador said, citing data from the Department of Environment and Natural Resources.
“In each territory, the eagles are faithful to their nests and they like to live in large and old-growth trees. Unfortunately, based on deforestation data since the early 1900s, when nearly everything was green, now we are left with few old growth forests,” Salvador said.
Another danger to the population of the Philippine eagle is the avian influenza, or bird flu, which is caused by viruses adapted to birds. This is a threat to the eagles, as the country remains a bird-flu free zone, according to PEF.
“Our worry is that when it begins to strike us, the population of the Philippine eagles will crash,” Salvador said.
The PEF’s proposal is for the country not to wait for that to happen and divide the captive gene pool of this critically endangered species.
Some of these should be sent to countries like the United States, where another Philippine Eagle Center could be set up for a separate breeding program.
This, Salvador said, would ensure that the Philippine eagle, despite the presence of avian flu, would not be extinct.
He noted that to preserve the country’s pride, PEF, with its army of eagle keepers and field researchers, is willing to go the extra mile.
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