A flock of birds form a heart-shaped formation as they gather at dusk before landing on trees for the night, on December 23, 2012 in Liernais, France. (Photo by Etienne De Malglaive/Getty Images)





A flock of birds gathered at dusk before landing on trees for the night, on December 23, 2012 in Liernais, France. (Photo by Etienne De Malglaive/Getty Images)





A picture taken on January 4, 2016 shows a murmuration of starlings performing their traditional dance fly before landing to sleep near the southern Arab Israeli city of Rahat, in the northern Israeli Negev desert. (Photo by Menahem Kahana/AFP Photo)





A picture taken on January 4, 2016 shows a murmuration of starlings performing their traditional dance fly before landing to sleep near the southern Arab Israeli city of Rahat, in the northern Israeli Negev desert. (Photo by Menahem Kahana/AFP Photo)





A picture taken on January 14, 2016 shows a murmuration of starlings performing their traditional dance before landing to sleep near the southern Israeli village of Tidhar, in the northern Negev desert. (Photo by Menahem Kahana/AFP Photo)





Black kites fly as a murmuration of starlings perform their traditional dance fly on February 10, 2016 near the southern Israeli city of Rahat. (Photo by Menahem Kahana/AFP Photo)





A picture taken on January 17, 2017 shows a murmuration of starlings in the sky of Pontevedra, northwestern Spain. (Photo by Miguel Riopa/AFP Photo)





A picture taken on January 17, 2017 shows a murmuration of starlings in the sky of Pontevedra, northwestern Spain. (Photo by Miguel Riopa/AFP Photo)





A picture taken on January 17, 2017 shows a murmuration of starlings in the sky of Pontevedra, northwestern Spain. (Photo by Miguel Riopa/AFP Photo)





A picture taken on February 4, 2018 shows a murmuration of starlings performing their traditional dance before landing to sleep near the southern Israeli city of Rahat, in the Negev desert. (Photo by Menahem Kahana/AFP Photo)





A picture taken on February 4, 2018 shows a murmuration of starlings flying before landing to sleep near the southern Israeli city of Rahat, in the Negev desert. (Photo by Menahem Kahana/AFP Photo)





A picture taken on February 4, 2018 shows a murmuration of starlings flying before landing to sleep near the southern Israeli city of Rahat, in the Negev desert. (Photo by Menahem Kahana/AFP Photo)





A flock of starlings is seen as they perform their traditional dance fly before landing to sleep during the sunset near the southern Arab Israeli city of Rahat, in the northern Israeli Negev desert, on February 2, 2015. (Photo by Menahem Kahana/AFP Photo)