Phl Eagle an important indicator of the state of the country’s forests

(Second of 4 parts)

Haribon cited the Philippine Eagle as a classic example. “The Philippine Eagle is among the critically endangered birds. It is territorial that when it bears an eaglet which only happens only after two years, the young birds will now be looking for their own territories or place in the forest but because of the continuous illegal logging and decreasing forest cover, the big question is, where are they to settle now?” biologist Blas Tabaranza Jr. asked.

The book “Vanishing Treasures of the Philippine Rain Forest” authored by Drs. Lawrence Heaney and Jacinto Regalado Jr., noted that the most widely recognized symbol for conservation is the Philippine Eagle (Pithecophaga jefferyi), the second-largest eagle in the world.

“These huge birds maintain populations only in old-growth lowland rain forest, although they will search for food in both old-growth and second-growth forest. They feed mostly on flying lemurs (also called kagwang), snakes, palm civets, flying squirrels, giant cloud rats and occasional monkeys. From what little is known, adults choose mates with whom they remain throughout their very long lives (perhaps 20 years),” according to the book.

Further, it said, “Pairs live within territories of 20 to 50 kilometers, usually constructing their nests in high treetops from which visibility is unusually good. They breed no more than once a year, and may skip years entirely; incubation of the single egg lasts about two months to reach the point of leaving the nest. With such a low reproductive rate, and such a large home range, it is not surprising that the destruction of the rain forest habitat has been devastating to the Philippine eagle. Once found on most of the large islands of the country, they are now believed to be extinct on all but Luzon and Mindanao, where the only large tracts of old-growth forest remain. Even worse, they can breed successfully only in lowland old-growth rain forest, the most ravaged habitat in the country.”

Survival or extinction

“Thus, the Philippine Eagle’s survival or extinction is watched as one of the most important indicators of environmental improvement or collapse.”

Tabaranza said that for the last 10 years, the number of Philippine eagle remains at 500. “What is most alarming now is when there comes a point when all these birds that reproduce mature or overmature. That is the time that they will stop reproducing, and that there is none to replace them,” he said.

Haribon pointed out that critically endangered species may survive from five to 10 years given their 50-percent chance of becoming extinct while endangered species’ survival could be up to 20 years. Meanwhile, vulnerable species can survive for the next 100 years. 

Tabaranza said birds are very dependent on plants as they feed on fruits, and on insects that feed on flowers of the plants. “Everything is interconnected — destruction of forests will not just affect the bird group only.”

Tabaranza said, “We, at Haribon, are advocates of conservation of wildlife, especially the birds but the message is for the people. The birds being affected by climate change are indicators. They indicate that something very bad is happening to our environment.”

He said if one sector of the ecosystem is affected by climate change, there will be a domino effect and other sectors will also be hit by these negative effects of climate change.

Forest clearing

Protected Areas and Wildlife Bureau assistant director Nelson Devanadera said habitat loss is a result of forest clearing. “In addition to this bird threat is the conversion of mangrove areas to fishponds for agricultural purposes. This affects bird life, especially their nesting and feeding activities,” he said.

Devanadera reiterated that the status of the Philippine Eagle indeed serves as an ecological indicator on the state of our forest ecosystem.

Dr. Danilo Balete, a research associate at the Field Museum of Natural History in Chicago, Illinois, agreed that habitat destruction is the most serious threat facing wildlife species, including birds. “Lowlands are where you can find serious destruction because it is inhabited by people, there is logging and kaingin,” he said.

Balete noted that destruction could be both natural and man-made. “The natural causes are part of the process being experienced by animals in their quest for survival but the impact of man-made destruction is the one gravely affecting the country’s wildlife. Trees are cut but there are no efforts to replace (these) trees.”

He said hunting is one of the factors driving the country’s native species to near-extinction. “The problem with native species is that they don’t produce as much or as frequent than exotic species,” he said.

Tabaranza said climate change is supposed to be a natural process. “However, if the temperature gets hotter than what is considered normal, then something not right is happening,” he said. (To be continued)