Last update - 00:00 29/01/2007
Watch the (disappearing) birdie
By Zafrir Rinat
The destruction of large birds of prey in Israel, such as vultures and eagles, received a lot of publicity. But much less is known about the threat facing ground-nesting birds, among them the plover. Destruction of the nesting area, due to human activity, and man-made changes to the environment, constitute the two biggest threats to these species. Due to these environmental changes, the species may spread to new areas, in order to find food and livable conditions. So, for example, the hooded crow, which destroys the eggs and chicks of other species, is expanding its living space: Because they feed on food scraps, the construction of new communities offers them new opportunities.
According to Ehud Hatzofeh, an ecologist in the National Parks and Nature Reserves Authority's Science Department, "the plover is becoming extinct because of what we have done to the coast: pollution, four-by-four vehicle traffic and the spread of birds such as crows, which attack it."
In large parts of the Negev, nesting birds that used to live there are gradually disappearing. "Hunting by Thai workers, poisoning and the transformation of natural areas into agricultural plots are destroying the sandy areas," says Hatzofeh. He also blames the Jewish National Fund, which is supposed to be sensitive to environmental issues: "They planted trees in large swaths of the Negev and in so doing destroyed the habitat of the ground nesters."
One of the species that is in perpetual decline is the houbara bustard, one of the most impressive ground nesters. Ironically enough, one of this bird's last refuges is the Hatzerim Air Force Base, which because it is fenced in, preserves within it a natural growing habitat that is suitable for houbaras. In the southern Arava, there are only a few hoopoe larks left; the hoopoe larks are part of the lark family. "This is a bird that nests in sand dunes, but there are hardly any such dunes left," says Hatzofeh.
A park under threat
While Israel's terrain is gradually emptying of native birds, the habitats of invasive species are expanding. Prominent among these species are the common mynah, the Burmese starling and the rose-ringed parakeet. Their invasion, after escaping from zoos and petting zoos, is a serious ecological problem, as they tend to encroach on local species' terrain.
One place where invasive species are flourishing is Hayarkon Park in the Dan region, which houses the Tzafari bird park. According to a paper prepared by Hebrew University students Yotam Orhan and Assaf Schwartz (under the direction of Dr. Salit Kark), which surveys invasive species in Hayarkon Park, there is a dominant presence of foreign species there. The study focused on mynahs and rose-ringed parakeets.
Schwartz and Orhan's research indicates that the invasive species have managed to thrive in their new surroundings due to their resourcefulness and quite a bit of aggression, which is directed mostly at local species; the local species have trouble facing the competition.
Observation of the mynahs explains the secret of their success. A large part of their time is spent on the grass patches where they hunt for insects and together chase away anything that tries to compete with them over food sources. They take over the nests of sparrows and great tits. Mynahs and rose-ringed parakeets also take over nests made by woodpeckers inside tree trunks. Orhan documented in the study a case in which mynahs took over sparrows' nests and got rid of the chicks that were there. Schwartz says, "in another case, several mynahs attacked a kingfisher that had caught a fish. They forced it to drop the fish and later ate it. In another case, they attacked a kestrel which had caught a chameleon and it too had to relinquish its prey."
There is no effective solution
Israel Nature Reserves and National Parks Authority officials say they are aware of the severity of the problem of invasive species, but so far have not found an effective solution.
Hatzofeh says, "now we are dealing mainly with preventing additional invasions. Next week, we will release a list of species whose import will be banned, because they may become invaders. We are not dealing with species that have already invaded and spread. We don't have the necessary resources or the legal jurisdiction. We also need public opinion to support methods such as trapping the birds and in some cases, shooting the birds as well. Recently, one of our rangers tried to shoot some non-native duck species imported from Holland that had escaped from a petting zoo in the North. He encountered opposition from residents and had to stop."
If you have information about invasive bird species observed in nature, please e-mail Assaf Schwartz at polshim@gmail.com.