Spring Migration of Birds of Prey : Raptors Soar Fearlessly Over Stormy Mideast

At first they were only specks of dust floating lazily on the edge of the binocular lens. But gradually they soared nearer and the outline of their wings became clear as they rode silently and effortlessly on the invisible crest of the wind.

They were steppe eagles and short-toed eagles and a small kestrel falcon carrying a light lunch--a mouse dangling haplessly from one claw. Spotters, camped atop a barren hill of shale outside this port city, counted 120 of the birds within half an hour, all of them headed north.

It was an advance party for one of nature’s most quietly dramatic rites: the annual spring bird migration. Each year at this time millions of raptors--eagles, hawks, falcons, vultures and other birds of prey--set out from their winter nests in the heart of the African bush lands and make their way north to their summer playgrounds of Europe and Asia, a journey of 5,000 miles that takes a month or more.

No one knows for sure how many pass this way. But in the spring of 1985 researchers counted 1,193,075--easily the world’s record.

Hitchhike on Currents

On their arduous trek, raptors conserve energy by soaring, rather than flapping their wings. They hitchhike along air currents that rise up from the Earth along the spines of high ridges and mountain ranges.

Because it offers no such rising currents, the sea forms a natural barrier to the migrants. They avoid the Mediterranean except at its narrowest points--the Straits of Gibraltar and Sicily. Others follow the currents up East Africa’s Great Rift Valley, which stretches north from South Africa to the Red Sea. They then fly along the coastline until they pour over Israel like a conquering army.

“It may be a problem from a political point of view to be at the juncture of three continents. But from a bird-watching point of view, it’s a paradise,” said Yossi Leshem, director of the Israel Raptor Information Center. Leshem and thousands of bird watchers descend annually upon Elat, which serves as the bottleneck through which the raptors must pass as they ride the invisible highway from Africa to the Russian steppes, the Caspian Sea and the Balkans.

The raptors fly only in daylight. They are most visible in late morning, when the rising heat currents carry them to the foot of the clouds. They eat little on the trip and drink even less, although many raptors have a gland in their beaks that can desalinate salt water.

Dangers Along Way

When the birds reach the north, they build nests, regain the weight they lost on the trip and begin reproducing. In the fall, the newborns join the trek south--but only three of 10 survive.

There are many dangers for the raptors as they make their way through one of the world’s most volatile regions. The most serious ones usually are man-made oil slicks along the beaches of the Red Sea, harsh pesticides in the cotton fields of Egypt and high-tension power lines strung along the Negev Desert in Israel.

Then there are bullets. In war-battered Lebanon, there are an estimated 400,000 hunters, some of whom have been known to take aim with automatic weapons at flocks. Tens of thousands of storks have been slaughtered in recent years along the coastline. “In a time when no one cares about the life of a man, no one cares about the life of a bird,” Leshem said.

Israel has proven to be more friendly ground. There are only 5,000 licensed hunters, and raptors here are under government protection. But pesticide poisoning took a heavy toll in the 1960s, especially when pest-control officials applied massive doses of thallium sulfate to crops in order to eliminate the Levant vole, a rodent that feasts on grain.

Species in Decline

The pesticide, now banned, killed thousands of voles. But raptors swooped down on the rodents’ poisoned, immobilized bodies. The result was the destruction of virtually all of Israel’s populations of buzzards, black kites, imperial eagles, spotted eagles, harriers, sparrow hawks, peregrines and merlins. Of the 23 species of raptors breeding in Israel since the turn of the century, Leshem estimates that about a third of them now are extinct and 40% of the rest are in serious decline.

A new potential threat is the government’s plan to allow the United States to construct a new Voice of America relay station south of the Dead Sea along one of the raptors’ favored flight paths. Conservationists contend that the high-energy microwaves transmitted from the station may prove a danger to the birds, a theory that proponents of the project say is unproved and specious. The final decision on the station’s location has yet to be made.

Israeli military aircraft are also a threat. From 1977 to 1982, the Israeli Air Force suffered an average of 100 collisions per year with birds, 10 of which would cause serious damage. The exact figures are classified, but officials concede that at least four planes were total losses.

In one case, a pilot was killed when a pelican cracked the cockpit glass and hit him in the head, causing him to lose consciousness and crash. In another, a honey buzzard hit the ejection handle, exploding the pilot out of the plane and causing another crash.

Research Project

“He was flying low and glancing at his map and the next thing he knew, he woke up in the hospital with a broken neck,” said Uri, a colonel in charge of Air Force safety, in an interview. He could not divulge his last name because of Israeli military rules.

To reduce the damage, Uri said, the Air Force funded research by Leshem and other raptor specialists that resulted in more precise mapping of migration routes and the establishment of bird protection zones that pilots are instructed to avoid from mid-March to mid-May and again in autumn. The result: collisions have been reduced by more than half and the damage has dropped from a few million dollars annually to less than $100,000.

“The birds were here before us and they’ll be here after us, so the solution is not to be in the same time and place where they are,” Uri said.

Like other raptor watchers, Bill Clark finds the birds irresistible. Clark, from Annandale, Va., gave up his job as a nuclear engineer at a Washington think tank to trap and examine the birds here.

‘Independent and Aggressive’

“It’s the way they fly, the way they look, their independence,” said Clark, 49. “Raptor people are different too, maybe a little more independent and aggressive. There’s a certain affinity.”

Clark’s traps include a wire cage with mice inside. When the raptor pokes his beak through the cage to get the mice, the beak instead gets caught in a small wire noose. Another is a live pigeon tethered to a pole. When the raptor descends, Clark sets off a spring-loaded net that ensnares both birds. Or, should a raptor stop at a pond near the grove where Clark waits, a compressed-air device launches a net over it.

Clark records the birds’ size and weight, bands them and lets them resume their flights north.

In the fall, the birds will head south for another season in the African sun. If they live 20 years, Leshem said, they will have traveled 200,000 miles, driven by their biological clock and by a restless instinct that admirers like Leshem and Clark can only imagine.