White storks that have nested in Poland are heading south for the winter earlier than usual after an especially hot, dry summer — a development experts are linking to climate change — and some have already been observed in Israel, which is a major migration route on the birds’ route to Africa.
In a rare case that has stoked Israeli ornithologists’ excitement, a stork has been observed over the last month nesting at the Beit She’an Valley, the only known nesting site in the world for storks located below sea level.
The valley is the one of the hottest areas in Israel, with temperatures regularly reaching 40 degrees Celsius (104 degrees Fahrenheit) in the summer — another unusual feature for a stork nesting site.
“White storks normally just fly through Israel,” ornithologist Nadav Israeli of the Society for the Protection of Nature in Israel told the Walla news site. “About 500,000 storks pass Israel in every migration season. However, a small nesting population has in recent decades established itself in the Golan Heights, where some 15 couples nest annually.”
The stork seen at the Beit She’an Valley is a single parent, another rare characteristic for the normally monogamous species. It originally hatched in the Golan six years ago.
The first stork was observed nesting at the Beit She’an Valley in 2007, when the mother was seen dealing with the heat by carrying water in its beak to the nest. It also took straw once every 15 minutes, dipped it in the water, and dropped it next to its chicks.
Israel, located at the meeting point of three continents, on the Syrian-African Rift Valley, constitutes a main migration route for 500 million birds that fly (in the autumn) from Europe and western Asia to Africa, and back (in the spring). Despite its relatively small size, Israel attracts approximately 540 species of birds.
Poland has a large population of white storks that arrive from Africa every spring and nest all summer before returning south by the end of August.
Gabriela Kulakowska, an ornithologist with the Polish Society for Bird Protection, said storks in many cases have departed about two weeks earlier than usual this year.
“The nests in the villages are already empty,” Kulakowska said Tuesday. “Ornithologists say they have never seen anything like this.”
She said that if the weather this summer is a result of climate change, “then this year’s early journey is also an effect of climate change.”
There is some disagreement about why exactly they are leaving early.
Because summer also came early, Kulakowska said the birds have had good conditions for breeding, feeding, and growing their chicks, and gathered the energy stores early to begin their long flight back to southern Africa.
Monika Klimowicz, with the Polish Society for the Protection of Birds, noted that this summer’s dry spell has meant there have been fewer insects, snakes, lizards, frogs, and small mammals for the storks to feed on.
Klimowicz said her organization has also observed the birds departing early and said that “most of the nests are already empty now.”
There are some 50,000 white storks that visit Poland every summer, making up some 20 percent of the world’s population. The numbers, however, are declining.
The birds are much-loved in Poland and a key element in folk beliefs and iconography.
People believed that if storks nested on their homes, it brought them good luck — and children. That idea was rooted in the fact that storks often arrived in spring, when human births were also at a peak, caused by the fact that women in the past were more likely to conceive at times of improved nutrition, Kulakowska said.