Yossi Leshem has been providing the Israeli air force with maps and forecasts of bird migration through Israeli airspace since 1983. He was the director of the Society for the Protection of Nature in Israel from 1991 to 1995. In 1996, he set up the International Center for the Study of Bird Migration at Latrun near Jerusalem. He has hundreds of Israeli, Palestinian and Jordanian schoolchildren following the birds鈥� progress online every day
Were you always a bird man?
When I was a child, my mother often took me hiking on Mount Carmel. She always said she couldn鈥檛 tell a bird from a donkey, but the walks made me a nature-lover. Since I was very young, I have dreamed of flying like the birds I saw soaring over that mountain. I wanted to become a pilot in the Israeli air force. But I had bad eyesight and needed glasses, so I had to join the army instead. When I left military service, I took up birding.
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Why is Israel so special for birds?
It is positioned at the junction of three continents. For politics that is a disaster, but for bird-watching it is a Garden of Eden. We are a bottleneck for bird migrations, one of the top places in the world. You can see about 540 species here, including 35 different raptors. A billion individual migrating birds come through every year. You can see white storks, lesser spotted eagles, honey buzzards and white pelicans.
They all use this 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.
But the birds are not alone up there鈥�
No. Israel has a higher density of fighter aircraft in its airspace than anywhere else in the world. So there is a huge conflict between flying machines and flying birds. Collisions are a big danger, for the birds of course, but also for our aircraft. Many more Israeli aircraft have been downed by birds than by enemy air battles in the last three decades.
How did you get involved with this problem?
I was studying ornithology and looking for a topic for my PhD. I was involved in a study of the almost extinct lappet-faced vulture at Eilat on the Red Sea, where Danish raptor experts had counted hundreds of thousands of raptors using just telescopes and binoculars. In 1980, we started an annual study of the autumn migration of raptors across Israel. A pilot suggested we should try and get a plane to go up on a busy day for bird migration and see if there were more birds aloft than we could see from the ground.
I thought this might make a good research project, and I went to the air force to try to get a plane. While I was there, they showed me the data on 10 years of collisions between aircraft and birds over Israel. I could not believe it. It was all secret data, so nobody knew about it publicly. But they had lost five aircraft, and there were more than three collisions causing major damage every year. They felt really helpless against this enemy.
It sounds unlikely that a bird could down a fighter plane.
Yes. But when a white pelican weighing 10 kilograms hits a plane going at 800 kilometres an hour, at the point of impact there will be a force exerted on the plane equivalent to about 100 tonnes. It鈥檚 devastating.
And you told them you could help?
I told them I thought I could map the soaring birds鈥� migration patterns and give the military forecasts, and real-time information, so they could avoid flying among the birds. To underline the point, I told them that during two weeks in May a million honey buzzards would be coming over the country.
Not long afterwards, I got home late one night and there was a message from a colonel asking me to be in his office at 8 am the next morning. At that meeting, he told me 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. He broke his neck, but he recovered.
I have since joked to that pilot that the timing of his accident was perfect. It made my career. I started work on my PhD at Tel Aviv University with the air force. And around the same time the problem became worse. Before 1983 Israeli planes did their training mostly over Sinai, but that year we gave Sinai back to Egypt. Suddenly we had much more limited air space, and the planes were concentrated in the middle of the birds鈥� flight paths.
How did you go about mapping the birds?
To start with, we used information from bird-watchers鈥� surveys. For more than 20 years, we have had hundreds of foreign ornithologists coming here to do a complete bird migration transect across the country. We pay for their lodgings. They love it. They get a free bird-watching holiday and we get fantastic information.
Since 1983, we have also used radar at Ben-Gurion international airport near Tel Aviv. At first, the experts told me that you could not see birds using radar. In fact, most air traffic people tune the radar so that it doesn鈥檛 pick out birds, which confuse their tracking of aircraft. We discovered that if we retuned the radar, we could spot the birds quite well.
In 1984 I produced the first map of what we call 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. It wasn鈥檛 perfect to start with, but it was a start and the pilots appreciated it.
What were the shortcomings?
The one thing neither the radar nor the people on the ground were good at was calculating the height of the bird flocks accurately. For that, I needed to go aloft. We tried a Cessna aircraft, but it was too fast and noisy for tracking birds. And normal aircraft cannot stay aloft for long enough to follow birds for a whole day. So I used a motorised glider. We could fly that for up to 11 hours at a stretch. It was perfect. I could literally fly with the birds, climbing with them on the thermals and then gliding.
The birds generally follow one of three known routes. But the height at which they fly varies, depending on conditions. Usually soaring birds keep to around 3000 feet. But when the thermals are strong they can go up to 10,000 feet. And during temperature inversions when the air is stable they may not go above 300 feet. So it is critical that the pilots get detailed forecasts and real-time information.
It sounds like a perfect marriage of your enthusiasms.
My childhood dream became a reality. I have flown 1400 hours on 230 bird-tracking sorties.
Have you saved aircraft too?
Since we produced the first maps, the rate of bird collisions with Israeli military aircraft has fallen by three-quarters. In the past 20 years, only two aircraft have been lost to bird collisions. The air force estimates we have saved it $660 million in lost aircraft, as well as the lives of several pilots, of course.
We now have radar stations monitoring the birds in the Negev desert as well as at our International Center for the Study of Bird Migration, which I set up at Latrun at the foot of the Jerusalem hills (). The monitoring system there operates 24 hours a day, seven months a year, providing daily bird forecasts and real-time warnings. It is as routine as the weather forecast.
鈥淲e hope the birds we track can be a symbol of peace. We give them Christian, Muslim and Jewish names鈥�
What do Israel鈥檚 neighbours think of all this?
The military people are quite interested, because they have similar problems with bird collisions. During joint manoeuvres over Turkey five years ago, Israel almost lost an F-16 when it collided with a buzzard. Our 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, but nothing is operational yet. I see cooperation over this problem as a catalyst for peace in the region.
How does it work for peace?
The centre at Latrun has been one of the pioneers in tracking migrating birds using tiny satellite transmitters attached to the birds. We have been following the migrations of white storks, griffon vultures and other birds that nest in summer across central Europe. As well as allowing us to study and protect their stopover sites, this project has been a big educational tool, illustrating our slogan that migrating birds know no boundaries. We hope the birds can be a symbol of peace. We give the ones we track Christian, Muslim and Jewish names, like Fatimah, Ahmed, Leah and Anna-Marie, and people can track them on our website.
For example, we have been tracking a white stork we call Princess for 10 years. She nests each summer 50 kilometres west of Berlin. She originally had a mate who migrated with her to Africa, going to Sudan and on to Cape Town. But she lost him and got another mate, Jonas, in 2001. They are unusual because they go their separate ways in winter. He goes to Spain while she still goes to Africa. But each spring he comes back to Germany and prepares the nest before she arrives. It鈥檚 a nice story, though exceptional.
Tell me about your work with Palestinian ornithologists?
We have a joint venture with the Palestinian Wildlife Society to track the storks and a griffon vulture called Salaam, which means peace in Arabic. Each year he goes from Mount Carmel down through Jordan and the Negev desert over Mecca and on to the nesting grounds in Yemen.
Since 1997, we have had links with 250 Israeli, Palestinian and Jordanian schools where the children go online each morning to check the progress of the birds we are tracking. The US government gave us $1.5 million to develop this project with Palestinian and Jordanian schools. In 1998 we had 5000 schoolchildren 鈥� Jews, Palestinians and Arabs 鈥� gathered at Latrun to learn about the birds that migrate across our countries. But since the intifada started in 2000, we haven鈥檛 been able to bring the kids together.
When peace comes, we plan to extend this educational work and run joint operations to invite tourists to bird centres: three in Jordan, three in Palestine and 10 in Israel. Already we have 200,000 Israeli tourists a year who come to see the cranes that winter in the Hula valley in northern Israel. That is 10 tourists for every bird.
How do you pacify Israeli farmers 鈥� don鈥檛 they hate the birds?
Yes, there can be a problem when birds eat crops, but not always. Another project of mine is to use birds to control rodent pests on farms, as an alternative to chemicals. Farmers in the Middle East have big problems with rodents and voles. Barn owls worked best: we discovered in tests on a kibbutz that if we put up nesting boxes we could attract hundreds of owls. A single pair with their chicks will eat 2000 rodents a year. So putting up 40 boxes will kill 80,000 animals. We published booklets in Arabic on how to do this, and now Palestinian and Jordanian farms are putting up nesting boxes too.
What鈥檚 your next big idea?
I want to help try to establish the Great Rift Valley as a world heritage site through UNESCO. It runs from Turkey all the way to Mozambique, a distance of 7000 kilometres, and all the way it is a major bird migration corridor. Along with Ethiopia and Germany, we plan to set up a crane bird centre, as the Ethiopians also have a lot of problems with bird collisions. So that is another avenue for cooperation. I firmly believe that birds can bring peace between nations.