Climate drives migrating birds away from Eilat

Dr. Reuven Yosef, an ornithologist, decided to close the Eilat International Birding and Research Station, where he has been trapping and ringing birds for 20 years, a few weeks early this year. The reason: A sharp drop in the number of birds passing through Eilat on their annual spring journey from Africa to Europe.

Worried about this shift in migration, Yosef contacted the Bonn, Germany-based organization responsible for implementing the international convention on protecting migrating birds, and asked it to conduct an urgent investigation into the acute decrease in the number of birds.

He is not the only one to express concern recently over the fate of migrating birds. Early this month, BirdLife, the foremost bird protection organization in the world, published a long-term study revealing that over the last three years, the number of bird species that migrate from Africa to Europe - to nest in the spring - has fallen by more than 50 percent. Researchers in Eilat and Europe believe that the dwindling numbers are connected to environmental problems like climatic changes, and increased use of herbicides and pesticides in Africa.

In the case of Eilat, Yosef says the decrease in the number of birds caught by his station, where they are tagged, is evidence of this.

"We typically trap an average of about 5,000 blackcaps (sivhi shahor kippah) each year and this year we trapped only 2,000. We trapped only 83 chiffchaffs (ilvit horef) as opposed to an annual average of 430, and we trapped less than 400 lesser whitethroats (sivhi tohanim) despite the annual average of 1,118. These are all small birds that cannot be counted in the air, and the only way to gage their numbers is by means of counting tagged birds. As far as larger species are concerned, we counted 4,200 levant sparrowhawks (netz katzar-etzbaot, sometimes called short-toed hawks) in the air as opposed to the usual 40,000."

Yosef's findings contradict numbers gathered in a survey by the Society for the Protection of Nature (SPNI) at its northern Ornithological Center.

"It's true that the number of migrating birds is dropping around the world, as are figures for other animals, but we have not seen an unusual drop in the number of birds this year and there has even been an increase in the number of blackcaps," reports center director Dan Alon. "We also found no decrease in the number of levant sparrowhawks. European surveys examine birds that arrive in Europe from other parts of , and therefore they are not connected to the situation in Eilat."

Alternative migration paths

Alon says that the falling numbers in Eilat may have been caused by some birds choosing alternative migration paths. He notes that shifts in the number of migrating birds from year to year are not extraordinary. He also cites massive flooding at the Eilat birding park this year, which may have prevented the birds from stopping at the site.

"We observed a decrease mainly in the species of birds that pass over Eilat rather than those in the north of the country," Yosef says.

"The flood at the birding park did not damage the area where we do our tagging, where birds may stop to rest and eat. It is true that there are years when we witness a shift in the numbers of birds, but the decrease this year is far beyond the usual changes, and represents something extreme. We must examine whether this is an ongoing problem."

	Chiffchaff and Blackcap. (Dr Ruben Yosef and Roberto Ricardo)