The great stork migration is upon us. Thirty-one thousand storks flew down the country to rest in the Negev and around the Dead Sea on Tuesday, before heading to their winter homes in eastern Africa.Tuesday was the first day of the height of the migration, Jonathan Meyrav, survey director and project manager for the Israel Ornithological Society, told The Jerusalem Post. The society is part of the Society for the Protection of Nature in Israel (SPNI).“This was the first big day of the height of the migration. For the next week to 10 days, we’re likely to see a lot of storks flying by,” he said. The migration will likely take six weeks since starting in early August. All told, 350,000 are expected to fly over the country from north to south in that time, he added. On Tuesday, the birds flew from the Beit She’an Valley, over Kfar Adumim, to land in the Negev.At SPNI’s suggestion, farmers in the Beit She’an area plowed their fields to uncover the rodents that plague them. The rodents made a tasty dinner for the storks.As it has every year for nearly 30 years, SPNI and the Israel Air Force are surveying the birds.The purpose of the study is two-fold, Meyrav said, for scientific purposes and to prevent collisions between jets and birds. The project began on August 1. Surveyors stand in a line in the northern valleys to watch the storks fly overhead and estimate the size of the flocks, and in the Judean desert to watch the birds land. Seven thousand birds flew over in one flock on Tuesday.On Wednesday, SPNI will send up a motorized glider to fly with the flocks. Throughout the migration, SPNI will be sending up planes to photograph and film the birds.More than 500 million birds of different types are expected to pass through the nation’s skies this winter.