Free as a bird: Celebrating World Migratory Bird Day

"As global ambassadors of nature, migratory birds not only connect different places across the planet; they also reconnect people to nature and to themselves like no other animals on the planet," said Sarah Wolman, the featured artist who designed the World Migration Bird Day 2021 poster. "The day is an important moment to reflect on our own global relationship with nature," the Alaskan added.

Migratory wintering seagulls traveling south from across northern Europe and Siberia through India fly above children taking a boat ride in the waters of Delhi's Yamuna river in the early morning. The birds arrive in the Indian capital annually as the locals celebrate the Makar Sankranti harvest festival in the old city.

Some birds remarkably fly the length of the planet, sometimes back and forth in a north-south direction on the same flyway or otherwise on a circular route. Journeying south during winters and returning during the northern spring, bird flyways include stopovers for food and rest. According to Bird Life International, around one in five bird species takes up the strenuous migration journey.

The lesser flamingo flies well above its main predator, the eagle, and its migratory route around eastern and southern Africa is relatively unknown. The smallest and most numerous of the world's five flamingo species, more than a million spectacularly gather on lakes Bogoria and Nakuru in Kenya's Rift Valley to breed and to feed on the blue-green algae that helps turn them pink.

Researchers and conservationists use bird bands to track migratory species and collect data about the places they breed, rest and hang out during the non-nesting months. The importance of tracking for conservation informed the theme of the 2020 World Bird Migratory Day, "Birds Connect Our World," which focused on ways to better map and understand migratory bird routes globally.

This blue-feathered barn swallow, a migratory bird, rests on a bamboo pole while searching for food in a fishpond in coastal Balanga in Bataan province, west of Manila. Great egrets, little egrets and whiskered terns also cross the South China Sea to the Philippines to escape northern Asian winters, notes the Wild Bird Club of the Philippines, which helps conduct the Asian Waterbird Census.

Huge great white pelicans, which can have a wingspan of 180 cm (6 feet), mostly migrate from eastern Europe and Russia to Africa. Flying south to breeding grounds in Tanzania and Ethiopia, thousands of migratory pelicans stop over in Israel and can be seen here at a reservoir in Mishmar HaSharon, north of Tel Aviv. Local farmers feed the birds in order to avoid damage to commercial fish pools.

This highly ritualized greeting ceremony is performed by migratory white storks, tall nomadic birds who form spectacular flocks when taking to their flyway in their thousands between Europe and Africa. They utilize warm thermal air currents to glide the long distances with ease and thus avoid the Mediterranean Sea, since these currents don't tend to form over water.

Snowy egrets are among some 400 species of migratory birds that rest on the shores of the Salton Sea in California. Fish once supplied abundant food for these birds but are dying due to the over-salination and drying up of the lake water. The destruction of these vital resting and nesting places for migratory birds typifies the conservation challenges that World Migratory Bird Day addresses.