The green heron is a stocky crow-sized heron. On adults, the wings and back are green mixed with blue-gray. The upper breast, sides of neck, and head are chestnut with a dark blue-green crown that can be raised to a crest when alarmed. In poor lighting, green herons may simply look dark. Young are more heavily streaked on neck and chest and duller and grayer on back. On being disturbed and when flying, its loud sharp call note resembles the harsh sound made by closing rusty scissors — skowp!
Similar species: Least bitterns have paler necks, buff and chestnut patches on their inner wings, and dark on the outer half of their wings. They are about two-thirds the size of the green heron, which lacks the light wing patches. American bitterns are larger, buff and brown, and lack a dark cap. Black-crowned and yellow-crowned night-herons are larger, grayer, and have thicker, shorter bills than green herons.
Length: 18 inches.
Habitat and Conservation
Most people see green herons as they forage in marshes and on the edges of tree-lined streams, ponds, and lakes. They can be difficult to see, as they move slowly or stand still amid vegetation on banks. When flushed, a green heron can seem awkward as it hurriedly flops away, but when it’s hunting, a green heron is smooth and stealthy, then lightning-fast and astonishingly accurate as it jabs for prey.
Green herons typically stand motionless at the edge of a pond, moving slowly and stalking small fish, frogs, and aquatic insects. They watch and wait for their prey to venture close enough to snatch. A heron captures its prey with a quick lunge, grasping it in its bill and swallowing it headfirst. The green heron can extend its neck a surprisingly long way as it lunges to capture its prey. This species is one of the few birds known to use tools: green herons sometimes drop small objects, such as twigs, feathers, or insects, onto the water surface, which lures curious fish within snatching distance.
Common summer resident; accidental winter visitor. In the past, this species has been called the green-backed heron, when it was considered a single species along with the striated heron (which lives in the Old World tropics and South America) and the Galapagos (or lava) heron. Currently, the three are viewed as separate species. Ornithologists carefully apply common names so that they match up with scientific nomenclature. When their understanding of species’ relationships causes them to alter the scientific names, the common names change accordingly.
Present in Missouri from mid-April through late October. Numbers are greatest from mid-May through the end of August. Unlike many other herons, green herons often nest solitarily, though they sometimes join colonies with other herons. Nests are built in forks of trees or shrubs and are well-hidden by surrounding vegetation, and often overhang water. Built of sticks, the nest is about a foot wide and quite shallow. Clutches comprise 3–5 eggs, which are incubated for 19–21 days. After hatching, the young remain in the nest for 16–17 days. Green herons can live to be at least 7 years old.
If you ever see a green heron stalking intently for prey along a stream or pond bank, you will probably get the impression that it is an intelligent bird. Many scientists would agree with you, considering the fact that this species is known to use tools — use one object to act upon a second object — to capture prey.
Two old-time Ozark names for this species were "fly-up-the-creek" and "shikepoke."
Scientists who study animal behavior ponder many questions when an animal is found to use tools, among them: Is the behavior innate, passed on through genes? Or is it learned by watching others of the species performing the behavior? Does each individual put his or her own creative twist on the behavior? Or can it be some combination of these?