The research of Guilad Friedmann, a doctoral student in the Zoology Department of the Tel Aviv University, is being conducted in collaboration with the KKL-JNF Land Development Authority, the Israel Nature and Parks Authority, and the Kfar Etzion Field School.
Leading the study are Dr. Yosi Leshem from Tel Aviv University and Prof. Ido Itzhaki from Haifa University. The study is observing a curious phenomenon: The relocation of the Long-legged Buzzard, a species of raptors, from the cliffs of the Judean Hills to the trees in the forests of the Judean Plain, and the competition that has arisen between this species and the Short toed Eagle, another raptor.
The raptors, who are at the top of the food chain, serve as a good indicator of the state of the habitat. “If the raptors are in the area, it means there are also mammals, snakes and other birds", explains Friedmann. “If we understand what we have to do in order to protect these raptors, and how to preserve their habitat, we will also know which areas must be preserved and where it is possible to make compromises with nature for the benefit of development and building.”
Up until now, Friedmann has located 29 nests of the Long-legged Buzzard and 39 nests of Short-toed Eagles in the Lachish region. Many of these nests are in KKL JNF forests. The raptors usually select a tree on the edge of the forest, and the forest provides them with good camouflage for the nest while preserving easy access to hunting grounds in the open fields.
“A forest is not just trees, but a complex ecosystem,” explains David Brand, KKL-JNF Chief Forester. “The more we fathom the different factors at play in the forest, the better we will be able to manage the system.” KKL-JNF supports many studies in varied fields of research, investing 5 million shekels a year, with an emphasis on applied research. “The aim is to fill the information gaps and provide tools and solutions for the work being done by KKL-JNF,” says Brand.
The Lachish region includes the largest sequence of open spaces in central Israel, which, biologically speaking, creates a quality region. Friedmann is tracking the activity of the raptors for the duration of the nesting period - building the nest, hatching, care of the chicks, and the flight of the young from the nest. Such an in-depth study of these species has never been undertaken in Israel or abroad.
It is very likely that this study will prove that human activity in one region affects another species in another region. For example, expanding the forested areas in the Judean Hills is one of the causes for the relocation of the Long-legged Buzzard to the plain, because this raptor hunts in unforested open areas. Moving to the plain compelled the buzzard to forego building its nest in the cliffs and to suffice with trees for building its nests. The Short toed Eagle, a less aggressive raptor that also lives in the Judean Plain, is having difficulty coping with the fierce competition that has suddenly befallen it.
Raptors are being tracked with minute GPS transmitters that are affixed to the backs of the adult birds. The sophisticated transmitters broadcast data about the bird’s activity - if it is flying or sleeping, if it is busy hunting or feeding its young, if it is near its nest or distant. The transmitter transmits the data by wireless technology, so that there is no need to recapture the birds. Four buzzards and three eagles have been equipped with transmitters to date. The cost of the transmitter is the main obstacle to fastening additional transmitters and expanding the data base.
Additional information is obtained by climbing to the nests and following the development of the chicks. What are they eating? How much do they weigh? What is their size? How do habitat and nutrition affect their development? Friedmann checks each nest twice in the course of the season, takes the chicks out, weighs them, measures them, and attaches rings to their legs.
Climbing to the nests is very delicate work, and for this the scientist is accompanied by a professional climber. Care must be taken not to harm the tree or the nest. If the parents are disturbed too much, they could abandon the nest and their young. Of course, these activities are done only with the approval of the Israel Parks and Nature Authority and with maximum care for the raptors' welfare.
It turns out that bird watchers and nature photographers, who may have the best of intentions, cause nests to be abandoned if they remain in the nest's vicinity too long. Of course, they are not the only natural enemy. Many of the chicks are eaten in the nest or immediately after flying away from it, and 90% of them do not reach adulthood. “Obviously, the research study disturbs the birds,” admits Friedmann, “but we are taking great pains to minimize the disturbance. If we do not learn how to protect the habitats, these species could be in danger of extinction in Israel".