Scientific Discovery: Long-legged Buzzard Migrates Backwards

What can the raptors of the coastal plain teach us about the state of open spaces in Israel, the importance of responsible management of these areas, and finding a balance between the need for development and the need for environmental protection?

By KKL-JNF STAFF
December 28, 2011 11:36
KKL-JNF

KKL_281211_D. (photo credit: KKL-JNF)

A research study on this topic, undertaken by postgraduate student Gilad Friedman in cooperation with KKL JNF and other organizations, was presented at the 32nd Annual Bird Watching Conference, December 26, 2011 at Tel Aviv University. Friedman’s research received much attention, because it revealed a surprising discovery. The Long-legged Buzzard, which is considered a stable bird (one that does not migrate), does in fact migrate. Furthermore, it migrates in the opposite direction from most bird species - from south to north!

The conference was organized by the Tel Aviv University Zoology Department, the Multidisciplinary Center for Bird Migration Research in Latrun and the Society for the Protection of Nature in Israel (SPNI). About one thousand people, experts as well as bird lovers, came to hear a variety of lectures about the winged world.

The speakers included Dr. Yossi Leshem on Hoopoe Foundation Activities, Ohad Hatzofe (Pelican Migration), Yoav Perlman (Nesting Survey in the Negev), Roni Malka and Roni Levana (Harassment by Photographers), Dan Alon (Bird Watching Tourism), Alon Rothschild (Nature Preservation), Dr. Eran Levine (Insect Bats in the Jordan Valley) and Amir Ben Dov (The Yellow-legged Gull), and there was an exhibition of spectacular bird photographs for the participants to enjoy in between the presentations.



Friedman’s research began pursuant to a curious phenomenon—the move of the Long-legged Buzzard from the precipices of the Judean Hills to the trees of the Judean Plain. This move instigated competition between the buzzards and the Short-toed Eagle, a bird of prey of another species.

KKL JNF has a unique interest in this research and therefore assists in covering its costs. Many of the ninety nests located by Friedman in the Lachish region are in KKL JNF forests. The raptors often choose to nest in trees that are on the edge of the forest, thereby safeguarding easy access to the open fields where they prey without forfeiting the protection provided by the forest.

Another topic relevant to KKL JNF is the effect of human activity and development on the ecosystem. Experts propose that the move of the Long-legged Buzzard from the Judean Hills to the plain is due to urban development, the expansion of natural woodland and the planting of forests. These ecological changes compelled the raptor to seek new locations and adapt to living in trees and not on mountaintops.

As a result of the transition, competition began with the current occupants of the area, the Short-toed Eagles. Evidently man’s activities in one area could indirectly affect another species in another area. The rivalry between these two species has never been investigated. In general, the Long-legged Buzzard is a species about which very little research or documentation has been done.

The state of raptors is a good indication of the state of their habitat, because they are at the top of the food chain. If raptors are proliferating, it is a sign that there is other wildlife in the area.

In his research, Friedman visits the nests, collects data on the development of the young and analyzes the food remains. He also conducts fieldwork studies using stuffed birds in order to observe territorial aggression. All the work is done with the permission of the Nature Reserves Authority.KKL

The lecture presented at the conference focused on a unique method of collecting valuable data—GPS transmitters that are attached to the backs of the birds. In addition to funding the research, KKL JNF also pays for the transmitters. The more transmitters there are, the more data can be collected.

These transmitters measure the exact location of the bird, its altitude, its flight direction and its velocity. This allows for defining its hunting ground and for checking whether there is an overlap between species. There is no need to recapture the bird, since the data is received by antenna, somewhat like a wireless Internet connection.

This is the first time in the world that transmitters have been attached to Short-toed Eagles and Long-legged Buzzards, and the results have been astonishing. According to professional bird watchers, the Long-legged Buzzard is not a migrant bird. A Long-legged Buzzard named Batsheva, one of five buzzards and seven eagles that have been wired, decided to give scientists a new writing assignment for their textbooks.

Batsheva checked out and left the borders of Israel in June for a vacation in Russia, a distance of almost 2,000 km. The returning resident reappeared in Israel in November. Her friend Abigail, another Long-legged Buzzard, traveled about 900 km to eastern Turkey and returned a few weeks ago. Another acquaintance Michal stopped over in northern Syria, completely ignoring international politics and security issues between the countries. Bible aficionados will have noticed that all the female birds were named after the wives of King David. The males did no worse and were also given biblical names.

Not only is this an exciting scientific discovery, since it proves that the Long-legged Buzzard does indeed migrate, but also because the migration is in the reverse direction than what is accepted—northward. This phenomenon is known in nature only when a certain bird has lost its way. Experts do not know yet how to explain this strange occurrence, and it is likely that more research is necessary, including study of the birds’ behavior while they are away from Israel.

The transmitters also provide a great deal of information about nesting and preying habits. Short-toed Eagles, for example, like to eat out. They fly long distances for preying purposes, up to 30 km. The buzzard prefers eating at home, up to 4 km away. The preying range of the Short-toed Eagle is much bigger than that of its neighbor, the Long-legged Buzzard, about eight times bigger. Friedman’s research is continuing, and the bird watching world is anticipating additional discoveries.

One of the supervisors of Friedman’s research is Dr. Yossi Leshem of Tel Aviv University. Another research study supervised by Dr. Leshem in cooperation with KKL JNF is investigating the effectiveness of the titmouse as a natural pesticide for the Pine Processionary, which damages the pines in KKL¬ JNF forests.

Dr. Leshem emphasized the great importance of collaborating with KKL JNF in the field of research. “As a green organization that is involved in the environment, we have an excellent basis for cooperation with KKL JNF,” said Dr. Leshem. “KKL JNF administrates vast expanses of open spaces, and therefore, there is great importance in the organization’s involvement in research studies in the world of nature.”

Scientific research helps us better understand the connection between different factors in the ecosystem. New data does not only satisfy scientific curiosity but also gives us tools for protecting the environment and for preventing damage to biodiversity.

For Articles, comments or use please contact
Ahuva Bar-Lev
KKL-JNF – Information and Publications
Email: [email protected]
Phone: 972-2-6583354 Fax:972-2-6583493
www.kkl.org.il/eng


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