The emerald-green birds first appeared in the trees around my Jerusalem apartment building several years ago, chasing each other raucously through the branches in the early morning and bestowing upon the neighborhood a certain tropical air.
Not long afterwards, the same exotic birds — green plumage, red beaks — began to be seen in significant numbers in the northern city of Nahariya, where my parents live, fearlessly battling burly black crows over aerial turf. They appeared outside my in-laws’ house at a kibbutz in the Beit She’an Valley, where, with mounting ferocity, they began undertaking seasonal campaigns against a nearby pecan tree.
The birds are ring-necked parakeets, and one should not be taken in, as I was at first, by their looks. They are an aggressive species of foreign invader, birds descended from pets brought to Israel from afar who tasted freedom years ago, saw that the land was good, and have been fruitful and multiplying ever since.
The parakeets are just one of the invasive species increasingly in evidence in recent years in Israel. Unbeknownst to most of the country’s human residents, something of an air war is on between newcomers — most of them pretty tropical birds brought here by people and inadvertently released into the wild — and the hoopoes, wagtails, hummingbird-like Palestine sunbirds, and other more meek and less flashy members of the local avian world.
All that is necessary to begin a new population is three or four birds, male and female, with the ability to thrive in the local climate, said Alen Kacal, manager of the Jerusalem Bird Observatory.
“If they start to breed, you’re in trouble,” she said. “Their aggressive nature means they will have an impact on the ecosystem.”
The ring-necked parakeets, for example, are increasingly moving into nesting spots preferred by more retiring local types, like the woodpecker. (Of more immediate concern to some humans is their tendency to wreak havoc on crops like sunflowers and nuts.)
Another of the invasive birds to appear in recent years is the common myna, a species native to southeast Asia with a black head, a yellow eye-mask and a yellow beak. The myna sometimes nests in traffic lights, and has been known to eat the eggs and chicks of rival species.
About ten of the mynas escaped in the 1990s from a bird park in Ramat Gan, said Yoav Perlman, a photographer and blogger who also serves as a researcher for the Israel Ornithology Center, part of the Society for the Protection of Nature in Israel. They now number tens of thousands and have spread throughout the country.
The parakeets date to an earlier jailbreak — one that didn’t happen by mistake. In the 1950s, he said, staffers at the Mikveh Israel agricultural school, near Tel Aviv, decided to release the birds into the wild, apparently thinking the country would benefit from the addition of a pretty tropical species.
Other countries have battled foreign bird invaders. Australia, for example, is waging an “all-out war” against the myna, Perlman said with approval. But in Israel little was done early on, and both populations have now grown beyond anything that can be controlled.
The list of invaders here is long and growing, with names often as colorful as their plumage: the streaked weaver, the mashed weaver, the warbill. The pheasant-like Egyptian goose. The house crow, from India, which first arrived on ships at the Red Sea port of Eilat and has made itself at home.
The new species have been turning up more and more at the Jerusalem observatory, a small center located on parkland near the Knesset and known, unjustly, to few outside Israel’s ornithological subculture. (There are two other Israeli observatories, one in Eilat and the other in the northern Hula Valley.)
Staffers and volunteers at the observatory track birds that stay in Israel year-round and the hundreds of species that come through twice annually, during the great avian migrations from Europe to Africa and back again. The watchers of the observatory are keenly aware of the unique nature, and the fragility, of local bird life. They seem to prefer the brown-headed and unobtrusive bolbol, for example, or the rather dull-seeming local sparrow, to any resplendent parakeet.
The migrating birds who arrive here land in Jerusalem after a strenuous flight over the desert, en route to or from summer homes that are sometimes as far away as Russia or Scandinavia. A few years ago, the Jerusalem watchers spotted an eyebrow thrush from Siberia.
“They want to spend a few days recovering, building up their fat reserves, and then they keep going,” said Kacal, the manager. They typically make only one stop in Israel.
As Kacal spoke, a few brown laughing doves alighted in the long grasses near the observatory’s pond. At a table nearby, a graduate student banded a sparrow and released it into the air. Frogs made an enthusiastic racket in the reeds. A lovely burst of birdsong came from the vicinity of Kacal; it turned out to be her cellphone.
This spring migration season brought a rare sighting at the observatory: a lesser whitethroat from England, banded in the past by the British Trust for Ornithology, taking an unusually circuitous route home from Africa.
When ecologists list the ‘big three’ challenges facing local wildlife across the world, the problem of invasive species is one of them
Because birds know no national borders, birdwatchers also try to ignore them. Neighboring Arab countries, including those with which Israel is officially at war, document birds banded in Israel and communicate the findings to their Israeli counterparts either directly or via the United Kingdom. On occasion, though, birds with Israeli bands are implicated in espionage allegations: A vulture caught in Saudi Arabia in 2011, for example, made international headlines after locals suggested a GPS device attached to it was meant to spy on the country. Similar charges were leveled against a European bee-eater found in Turkey last May, and against another vulture in Sudan in December.
Alongside the familiar local species of migrants and year-rounders, the Jerusalem bird-watchers are counting increasing numbers of invaders. The day before my visit, two mynas showed up and were duly — and unhappily, it seemed — noted by the staff.
When ecologists list the “big three” challenges facing local wildlife across the world, the problem of invasive species is one of them, said Perlman of the Society for the Protection of Nature in Israel. The other two are habitat destruction and over-exploitation of resources.
Data on Israel’s tropical bird invasion are still sketchy, Perlman said.
“In Israel, these phenomena are relatively new. We still don’t have enough information to know precisely how the local bird populations are being affected,” he said.