THE Philippine Eagle week ended Saturday, and it is just proper that we close the festivity with a feature about Raptors, of which the Philippine eagle is the “archetype”.
As the feathered “dinosaurs” of modern age, they are regarded as “Lords of the Skies”. Their razor-sharp talons and streamlined bodies bear the likeness of the velociraptors of famed Jurassic film series. Many traditional cultures across the globe have revered them.
But what are Raptors?
“Raptor” comes from the Latin word rapere, which means “to seize” or “to plunder.” Such a name is appropriate because these birds, or birds-of-prey as they are also called, feed on animals by seizing, killing and eating the flesh or by plundering their carcasses, as in the case of vultures.
Other birds, such as crows, fish-eating herons and gulls also snatch and kill their prey, but unlike raptors (except for vultures who feed on carcasses), they use their bills rather than their feet or talons.
Raptors are perfect killing machines. They have specialized feet for striking and piercing prey, and a powerful hooked beak that they use to tear flesh.
Their eyesight is superb, with twice the magnification and eight times more details than human eyes. Such powerful vision allows them to easily spot a bird more than three kilometers away. All raptors fly well and can perform spectacular aerial maneuvers. Forest hawks owe their great maneuverability to their short and broad wings paired with a long tail.
Among vultures, long and broad wings allow long hours of soaring while in search of a carcass. For sprint fliers like falcons, their long, narrow, and pointed wings paired with aerodynamic, bullet-shaped bodies allow them to dive accurately on their prey.
Raptors are primarily carnivorous. Smaller raptors (falcons, falconets) may feed on insects, frogs, reptiles, or small birds while larger ones on other vertebrate groups, mostly birds and mammals.
But raptor size does not limit prey size because many are able to catch, kill, and carry prey larger than them. A Philippine Eagle for instance once fed on a deer twice its size. Raptors associated with water bodies (sea eagles, kites, and ospreys) feed also on animals other than fish. Among several species, specific animals are eaten.
For instance, honey buzzards feed mostly on grubs and honeycombs of bees and wasps; America’s snail kites on freshwater snails; and Zimbabwe’s black eagles on a diminutive and distant relative of the elephant, the hyraxes. But for scavengers like vultures and a few kites, almost everything is practically eaten.
Keepers of ecological integrity
Raptors keep the balance in the community of which they are a part. They prevent prey population from increasing rapidly by feeding on few individuals. By doing so, overcrowding and the subsequent over-exploitation of habitat resources is prevented.
Raptors often feed on old, sick and very young animals that are easy to catch and handle. This leaves fit animals to breed and maintain a healthy population.
Ecological whistle blowers
Raptors are good ecological indicators. Being predators at the top of the food chain, they are sensitive to environmental contaminants.
For example, studies made by American bird experts during the 1960’s indicated that Bald Eagle eggshells were abnormally thin causing eggs to break during incubation. Chemical analysis revealed high DDE (a derivative of DDT) levels in eggs.
DDT, a major ingredient for pesticides used during that period, was ingested by Bald Eagles from contaminated fish. The use of DDT in pesticides and fertilizers were banned in succeeding years, which resulted to a remarkable recovery in Bald Eagle populations.
Masters of the skies
Raptors are among the most spectacular birds of the world. Their orders of magnificence range from the biggest and most powerful eagles and vultures to the fastest, most agile falcons and falconets.
Raptor flights provide man with spectacular aerial shows. A pair of eagles in courtship display mutually present talons in mid-air or mutually soar to great heights. Two sea eagles may lock talons in mid-air and rapidly descend in a death-defying spin while fighting over a territory. Hunting Peregrine Falcons may swoop directly at their prey at a speed of 240 km per hour.
Dwarves and giants
Raptors vary in size, form, and appearance reflecting the variety of habitats where they live. Sizes range from the sparrow-sized Philippine falconet, to the huge, 10 to 13 kilogram Andean Condors of South America.
Size difference between sexes (sexual dimorphism) varies, but it’s the female who is larger than the males. Species that hunt a greater variety of prey animals have substantially larger females than the males. Our country has the slightly dimorphic Philippine Eagle, with females that weigh up to 6 kilos, and males 4-5 kilos.
How many are they? Throughout the world, at least 290 species of diurnal (day-time active) raptors are known. Scientifically, raptors represent the Order Falconiformes. Based on evolutionary origins, they can be further divided into five sub-groups: New World Vultures, secretary birds, ospreys, falcons, and the eagles, hawks, kites, harriers, buzzards and Old World Vultures, grouped together as accipiters.
The Philippine’s share comprises at least 30 species: an osprey, six falcons, and 23 accipiters.
Unfortunately, three species that are found only in our country are threatened with global extinction: the Philippine Eagle and two species of Philippine Hawk-Eagles.