A baby Black-crowned Night Heron squawks in its incubator while being cared for at City Wildlife rescue and rehabilitation center in Washington, DC on May 31, 2017. The heron is one of several that have been brought to CW by the staff at The National Zoo over the past few years. (Photo Linda Davidson/The Washington Post)

Migrating gray cranes, on November 30, 2009 around the Hula Lakes in northern Israel. (Photo by Uriel Sinai/Getty Images)

A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)

A murmuration of migrating starlings is seen across the sky in southern Israel December 31, 2015. (Photo by Amir Cohen/Reuters)

A murmuration of migrating starlings is seen across the sky near the village of Beit Kama in southern Israel on January 16, 2018. (Photo by Amir Cohen/Reuters)

Migrating starlings fly in formation near the southern Israeli town of Rahat February 2, 2015. The phenomenon, known as murmuration, is most common during the winter months. (Photo by Nir Elias/Reuters)

A supporter of the Houthis has a poster attached to his waist of Iranian Major-General Qassem Soleimani, head of the elite Quds Force, who was killed in an air strike at Baghdad airport, during a rally to denounce the U.S. killing, in Saada, Yemen January 6, 2020. The writing on the poster reads: “God is the Greatest, Death to America, Death to Israel, Curse on the Jews, Victory to Islam”. (Photo by Naif Rahma/Reuters)

In this Friday, February 6, 2015 photo, sandhill cranes begin to stir after resting for the night at a roosting location along their winter migration route in Cecilia, Ky. According to counts made by biologists with the Kentucky Fish and Wildlife Resources, about 12,000 of the birds have stopped in Cecilia this week during their winter northward migration on their way to their nesting grounds in the Great Lakes region. (Photo by David Stephenson/AP Photo)