For the Birds Radio Program: Birds in the News: protecting Israeli aircraft and birds

Original Air Date: Nov. 4, 2004

An Israeli ornithologist is working on protecting Israeli military aircraft from collisions with migrating birds by mapping bird migration and how high birds are depending on weather, to figure out where and when aircraft can fly most safely during migration. Thanks to his work, bird-aircraft collisions have declined 75 percent.

Duration: 5′24″


One of the most interesting news stories I’ve read in a long time is from a recent New Scientist magazine about the Israeli ornithologist Yossi Leshem. He’s an expert in bird migration patterns across the Middle East who has turned his passion into a small industry responsible for saving the Israeli air force more than half a billion dollars in hardware and, no doubt, the lives of several pilots. Mr. Leshem was an active birder in Israel, which is positioned at the junction of three continents. He says that for politics that is a disaster, but for bird-watching it is a Garden of Eden, in a bottleneck for bird migrations. You can see about 540 species in Israel, including 35 different raptors. A billion individual migrating birds come through every year, including White Storks, Lesser Spotted Eagles, Honey Buzzards, and white pelicans, all using the land bridge between Africa, Asia, and Europe. Many heavy birds have to travel overland because they need the thermal currents created by the sun heating the land. The thermals lift them to heights from which they can glide and conserve energy. These soaring birds fly only during the day and avoid crossing large bodies of water like the Mediterranean. They prefer narrow valleys and mountain chains, where the uplift is strongest. The rift valley is perfect for this, and it makes Israel an international crossroads for birds.

Unfortunately for everyone, the birds are sharing that airspace with Israel’s fighter aircraft. Collisions are a big danger. Many more Israeli aircraft have been downed by birds than by enemy air battles in the last three decades.

When Dr. Leshem was working on his Ph.D. in 1980, he learned that the Israeli air force had lost five aircraft to birds, and there were more than three collisions causing major damage every year, noting that when a white pelican weighing 10 kilograms hits a plane going at 800 kilometers an hour, at the point of impact there will be a force exerted on the plane equivalent to about 100 tonnes. So he told the air force he could map the soaring birds’ migration patterns to give the military forecasts, and real-time information, so they could avoid flying among the birds. He mentioned that during two weeks in May a million honey buzzards would be coming over the country. Not long afterwards, he got home late one night and there was a message from a colonel asking for a meeting—he told Leshem that a honey buzzard had just destroyed a $5 million Skyhawk flying near Hebron. The pilot survived because the bird came right through the windscreen and hit his ejector handle. It literally ejected him. So he started work at Tel Aviv University with the air force. And around the same time the problem suddenly became worse. Before 1983, Israeli planes did their training mostly over Sinai, but that year they gave Sinai back to Egypt. Suddenly they had much more limited air space, and the planes were concentrated in the middle of the birds’ flight paths.

Dr. Leshem started mapping migration using information from bird-watchers’ surveys. And in 1983, he started using radar at Ben-Gurion International Airport near Tel Aviv. In 1984, he produced the first map of what he calls bird-plague zones, areas where the soaring birds are flying. Pilots are told to keep out of these areas. The only exception is during times of war. The maps are hung in the briefing rooms of every squadron during bird-migration seasons. He also started flying in a motorized glider, literally flying with the birds, climbing with them on the thermals and then gliding to get the altitude which he quickly learned depends on weather conditions. Usually soaring birds keep to about 3,000 feet, but when the thermals are strong they can go to 10,000 feet, and during temperature inversions when the air is stable they may not go above 300 feet.

Since he produced the first map, the rate of bird collisions with Israel military aircraft has fallen 75 percent. In the past 20 years, only two aircraft have been lost to bird collisions. The air force estimates they’ve saved $660 million in lost aircraft as well as the lives of pilots.

The monitoring system there operates 24 hours a day, seven months a year, providing daily bird forecasts and real time warnings. It’s as routine as the weather forecasts. Israel’s next step is to try to set up a regional warning system, linking the Israeli, Turkish, and Jordanian air forces. There have been meetings with both Jordan and Turkey, and although nothing is operational yet, Dr. Leshem sees cooperation over this problem as a catalyst for peace in the region.