Migrating birds, like the half billion that pass over and through Israel each spring and fall, can spread more than infectious diseases. They can also spread good neighborliness, safety, education, excitement and awe. These aims are also being advanced by Tel Aviv University ornithologist Dr. Yossi Leshem - the highly regarded founder and director of the decade-old International Center for the Study of Bird Migration in Latrun off the Jerusalem-Tel Aviv Highway - who has had birds on his brain for three decades. The 58-year-old zoologist (married with five children and several grandchildren) is perhaps best known here for his work to prevent collisions between IAF aircraft and migrating birds. Linking the three continents of Asia, Europe and Africa, Israel is a unique bottleneck for over 500 different species of migratory birds when they fly north in the spring and south in autumn. "Our location is a political disaster, but it's a paradise for bird lovers," he says. With a higher density of military training flights than anywhere else - and even more dense since Israel returned the Sinai to Egypt - the chances for collisions are relatively high. In the past 30 years, many more Israeli aircraft have been downed by birds than by enemies. Collisions have caused countless accidents, the deaths of three IAF pilots, major damage to planes and, of course, the death of many birds. Studying birds for his doctorate, Leshem focused on the nearly extinct Lappet-Faced Vulture in Eilat, and on the autumn migration of raptors across Israel. "A pilot suggested we 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. He told me that a honey buzzard had recently destroyed a $5 million Skyhawk jet near Hebron. That pilot had survived because the bird made a hole in the windscreen and by chance hit his ejector handle, expelling him and activating his parachute. He was seriously injured but recovered." THINKING THIS could make a good research project, Leshem contacted the IAF, which showed him classified data on bird collisions. "I couldn't believe it! They had lost five aircraft, and there were at least three collisions causing major damage every year. They felt helpless." His TAU doctoral research on the phenomenon led to a project, with the cooperation of the military and the Science Ministry, that has reduced the number of bird strikes by 76% and saved over $660 million, not to mention a number of lives, both human and avian. Today a lieutenant-colonel in the IAF reserves, he continues this research. Leshem previously worked for 25 years as a guide, field study center director and then executive director of the Society for the Protection of Nature in Israel (SPNI). Combining his loves of ornithology and flight, Leshem also regularly piloted small planes and gliders to "fly with the birds," warn the air force of their presence, and document their flight paths. After each collision, the bird control unit Leshem established collects bird remains from the aircraft or runway. The downy barbules of feathers have microscopic structures (similar to fingerprints) that make species identification possible even when only minuscule remains are found. Often full of blood, grease and other debris, the feathers are then sent to TAU's Laboratory for Feather Remains Identification. As part of a cooperative project between the IAF, TAU, SPNI, the Royal Netherlands Air Force and the University of Amsterdam, an identification software program was developed for cataloging feather microstructures, bird calls and distribution maps for 175 species,. In the early 1980s, primitive radar equipment was installed in the south at the same time the giant Voice of America radio transmitter was installed under US government pressure. Israeli ornithologists feared the electromagnetic radiation would confuse migrating birds, so Swiss equipment was brought in to follow their movements. Today, a camouflaged onion-shaped bird radar is located at the Latrun Armored Corps Memorial. Run by Dr. Leonid Dinevitch, a former Russian general who was in charge of weather radar facilities throughout the former USSR, the MRL-5 unit was purchased at rock-bottom price thanks to Dinevitch's connections. Although experts had long believed flocks could not be tracked on radar, Dinevitch and his colleagues proved them wrong by changing the facility from an analog weather-tracking center to a digital bird-tracking center. With enough space for only six people to sit, it has 3-D display computers showing flocks passing over Israel's "waist," and informs the IAF in real time of conflicts with training flights. The airborne routes at specific altitudes and locations of storks, pelicans, cranes, vultures, eagles and many other species are shown. Additional sites in the north and south will soon cover the entire country. The data are provided for all to see on the Latrun center's multimedia-rich Web site called "Migrating Birds Know No Boundaries" (www.birds.org.il) in Hebrew, English, Arabic, Russian and Amharic. During a press tour of the Latrun center organized by INFO-Mishkenot, Leshem wows his audience with a short film showing the collision of a baseball thrown by a pitcher with a small bird; because of the speed of each object, both the ball and the bird are pulverized. Think what the collision between a raptor or peace-loving pelican and the steel face of an air force jet or helicopter can do. Some debris from an F-15 hit by a stork is displayed on the base of the radar station. While the radar is not infallible because individual birds cannot be picked up, it has made a big difference. THE ARRIVAL of thousands of hungry pelicans, which each consume 1.2 kilos of fish per day, was not welcomed by fish growers, who saw their profits being gobbled up. Farmers whose crops were ravaged by birds demanded compensation. Leshem and his colleagues saved the day by setting up feeding grounds (migratory bird "restaurants") with cheap chickpeas, corn and peanuts that kept birds away from fields and thus saved their lives. In addition, hybrid fish used to keep down insect populations in ponds were served to pelicans and other fish-eaters. Leshem is in charge of tracking dozens of large migrating birds fitted with expensive satellite transmitters. These battery-operated devices, from which a small antenna protrudes, give scientists reports of the birds' whereabouts during their flights and "vacations." Leshem explains that even small birds can fly long distances, and do so more frequently at night to avoid the heat. But large raptors, storks, pelicans, cranes and other heavy birds can't cover thousands of kilometers during seasonal migrations by flapping their wings. Instead, they conserve energy by soaring, taking advantage of "thermals" - wind currents rising from the heated earth during the days. Since Israel lies along the shortest land route, dozens of species use it as their corridor, gliding and landing for a day or more to eat and rest. The transmitters can provide some juicy stories, like those of detectives hired to keep an eye on errant spouses. With amusement, Leshem relates the true story of Princess, a white-and-black stork, and her steady mate, Jonas, who have for years nested in the village of Loburg near Berlin. She has always passed over Israel (one of 105,000 of her species) to reach Sudan and then on to Capetown, while her mate - apparently happy to live off European garbage dumps - spends a separate winter in Spain. Aware of the change in daylight hours, they always left Germany in the autumn and their vacation spots at the beginning of spring within days of each other. But one year Princess was delayed in her return flight, and when she got to the same nest in the same tree, she found two-timing Jonas with another stork, who had laid two eggs in "her" nest! Leshem, who identified their location with the transmitter and sent bird watchers to see, said Princess tried to shoo her rival away for two weeks, but to no avail. Eventually she went off and found a new mate. Another project Leshem initiated is the use of barn owls to control rodents on farms. One white nesting box for owls is located near the radar center in Latrun. A pair of owls and their chicks can eat 2,000 mice and voles a year. Jordanian and Palestinian farmers have learned from his Arabic booklets, and are setting up nesting boxes on their farms as well. Love for birds has brought together schoolchildren around the world. Leshem's Web site offers educational programs for seventh to ninth graders. A teleprocessing project - the initiative of the Latrun center, the Technion's Recanati Science Museum in Haifa and the Weizmann Institute in Rehovot - offers multi-disciplinary material on bird migration, science, technology, space, biology, ecology, geography, physics, economics, Jewish and Zionist heritage and art; Diaspora children can also learn Hebrew through the site. With $1.5 million in US government funds, another computer project has hundreds of Israeli, Palestinian and Jordanian schoolchildren following migratory birds' progress online every day. "We give the ones we track Christian, Muslim and Jewish names, and young people can track them on our Web site." Over the past eight years, he has linked 250 Israeli, Palestinian and Jordanian schools whose pupils go into the Web site every morning to check on the location of birds the Latrun center is tracking. Leshem has also forged ongoing contacts with the Turkish and Jordanian air forces, organizing informal meetings in both countries. He has also brought together Palestinian and Jordanian ornithologists, who trade information with their Israeli counterparts. With more donations and cooperation, he hopes that regional cooperation on bird migration monitoring can be established in 23 countries along the Syrian-African Rift that runs from Turkey to Mozambique and passes through the Jordan Rift. He would like UNESCO to recognize this Great Rift Valley as a World Heritage Site. With 70 million active birdwatchers around the world, Leshem encourages as many as possible to come to Israel, where they can see more species and greater numbers in one small area than in any other spot. About 200,000 tourists come to Israel each year to see birds wintering in the Hula Valley. Leshem believes that many more can be attracted by organized birdwatching tours. One famous bird lover (and peanut grower), former US president Jimmy Carter, was in Israel last January to supervise Palestinian Authority elections. When Leshem sent an invitation, Carter dropped everything and found time to visit the Jerusalem Bird Observatory (JBO) in the shadow of the Knesset in Jerusalem. Founded in 1998 on a neglected, five-dunam spot in the middle of urban Jerusalem, it consists of a small wooden building for examining and banding small migratory birds, plenty of fruit- and seed-filled trees ("a good fig tree is one covered with bird excrement, because it shows they use it," Leshem explains), and a hut with benches and low windows where adults and children can observe nature 24/7. JBO's dedicated director is 40-year-old Amir Balaban, who admits that he was arrested at 11 when he saw a falcon's nest and tried to raid it; his "punishment" was to participate in a birdwatching club, which led to his work as an ornithologist, bird photographer and wildlife artist. "When we started it, nobody believed Israeli second graders would sit quietly for an hour to observe birds," says Leshem, who points out species drinking juice from upturned plastic bottles, bathing in a fountain, fighting and courting. There are even snakes and hedgehogs in the evening. The helipad where Prime Minister Ariel Sharon lands from his ranch on Sunday and military and police helicopters regularly use doesn't seem to bother the birds, who hide inside the hollows of trees. Almost invisible mesh nets are hung in the morning to catch specimens, which are collected unharmed, put in a cloth drawstring bag and gently examined. Balaban shows how to determine how long a bird will stay: It all depends on how much "brown fat" they have on their abdomen. It is this fat that powers their flights. He turns one female redstart - a tiny insect eater with a red tail - on her back and puffs on her feathers. Weighing in at only 16 grams, she has brown fat score #1, meaning she will have to fatten up at JBO for a few weeks. Although much of the world is becoming hysterical about avian flu, Leshem and Balaban are not panicking. Used to periodic health scares involving birds, they even welcome the attention given to their migrating friends, and are ready to take samples from birds they catch to monitor pathogens - if the government is willing to pay for it.