Black tern

The black tern is a small, striking bird found across Europe, Western Asia, and North America. Renowned for its dark plumage, this bird measures approximately 25 cm in length, with a wingspan of 61 cm, and a weight of around 62 grams. During the breeding season, it exhibits a dark grey back, white forewings, and a black head, neck, and belly. Outside of the breeding season, the black feathers turn grey.

One of the most fascinating aspects of the black tern is its dynamic flight. It moves with rapid wing-beats and erratic dives, especially when hunting for food. Notably, hybridization between black terns and white-winged black terns has been documented in areas such as Sweden and the Netherlands.

When it comes to breeding, black terns favor freshwater marshes. They can be found nesting in Canada, the northern United States, Europe, and western Asia. They typically build their nests on floating material in marshes or on the ground near water, laying between 2 to 4 eggs.

Unfortunately, the black tern population in England was eradicated in the 19th century due to extensive drainage of their breeding grounds. Today, North American black terns migrate to northern South America, while those from the Old World spend their winters in Africa. They forage by picking up food items near the water's surface or catching insects mid-flight.

The North American black tern population has been declining, mainly due to habitat loss. To help protect these birds, the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) includes them. Occasionally, black terns from North America have been observed as far away as Britain and Ireland.