The Grey Heron is a pronounced colonial nester that builds its nest high up, often many pairs in the same stand of trees, where it becomes easy to spot in spring.
Site: high up in the crowns of tall trees, preferably pine, but sometimes also down in dense reed beds by water.
Construction: a large, unwieldy stick nest of branches and twigs that the pair adds to year after year until it becomes very bulky.
The colony: several to many nests gathered in the same place, a so-called heronry, which can be used for decades and becomes noisy during the breeding season.