Philippine eagle has unique evolutionary history

From the Philippine Eagle Foundation:

The country’s national bird, the Philippine Eagle, is one of a kind, not only because it is found nowhere else, but also since it has a unique evolutionary history, clearly distinguishing it from other giant eagles once thought of as its immediate family.

At least this is what a recent study of the Philippine Eagles’ DNA suggests.

Scientists from the University of Michigan USA analyzed DNA isolated from blood samples of Philippine Eagle and those of the Harpy Eagle and Crested Eagles of the Americas and the New Guinea Harpy Eagle of New Guinea, all equal heavy weights of the bird world. All of the last 3 giants named are close relatives as revealed by DNA sequences, but only remotely related to the Philippine Eagle.

According to Dr. David Mindell of the University of Michigan, the Philippine Eagle was once grouped with 5 bird giants (the other two being the Crowned Eagle and the Solitary Eagle in the Americas) because all these species share extremely large size, with female wing-spans between 1.5 to 2.0 m and female body weights from 6 to 9 kg.

He also said that all of the 5 traditional “harpy eagle group” members live in tropical forests, feeding mainly on medium-sized mammals.

“But based on the genetic analyses, the similarities between the Philippine Eagle and the other harpies resulted not from kinship but from convergent change, driven by natural selection for reproductive success in tropical forests and a shared taste for mammals”, Dr. Mindell added.

Amazingly, Mindell’s team also found that the only distant relatives of Philippine Eagles are snake eagles found elsewhere in Southeast Asia and far Africa. In the Philippines, it is distantly related to the featherweight but equally imposing Serpent Eagle, which breeds in this country but is also common in Asia.

The study of Dr, Mindell’s team passed expert reviews and was published in the scientific journal “Molecular Phylogenetics and Evolution”.

The country’s conservation flagship, the Philippine Eagle is undoubtedly a world celebrity. Dubbed “King of Birds”, this top forest predator is unrivaled by any Philippine wildlife in terms of local and international publicity and interest.

The famous aviator Charles Lindbergh called it the “world’s noblest flyer” to call the world's attention to its troubles. In 2000, famed scientist E.O. Wilson listed the Philippine Eagle in the Hundred Heart Beat Club - animals likely to become extinct in the near future.

But all the fame and publicity has not spared the species from endangerment. Its population status remains precarious as recent estimates suggest that there may be 500 or fewer pairs of them left in the wild.

Sadly, eagles are still losing the forests which they cannot live without. Barely 3 % of the country’s old growth forest remains, most of them threatened by expanding agriculture, illegal logging and mining.

Many eagles are also still being shot or trapped, either for food, out of despair over livestock allegedly lost to nesting eagles, or out of plain curiosity and ignorance.

In the face of deforestation and continued persecution, the future of our national bird remains bleak.

According to Dennis Salvador, Philippine Eagle Foundation Executive Director, the recent finding of Dr. Mindell’s team definitely will not save the eagles overnight, but can be another compelling reason why Philippine Eagles need to be saved.

“They are a unique and priceless component of the natural heritage not only of the Philippines but also of the world” he added.

DNA is an abbreviation for deoxyribonucleic acid, the material of inheritance. It is made of chemicals which provide the instructions influencing how organisms should look and behave. Ask why a dog looks and acts like a dog, and humans not as chimpanzees, and you will find that the DNA is behind that.

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