Green Heron

Butorides virescens
Chucklehead, Little Green heron, Poke
The Green heron is a small solitary heron that lives along shaded riverbanks or quiet streams in areas of dense vegetation. It is often somewhat secretive but is sometimes to be seen crying "kyow" while flying up a creek. When in the open, it will often flick its short tail nervously, while raising and lowering its crest. The "green" of its back is an iridescence, and often appears as a dull blue or just dark.
Unknown

population size

8 yrs

Life span

135-250 g

Weight

41-50 cm

Length

52-68 cm

wingspan

Disrtibution

Green herons come from the Americas and occur in North America, Central America, and the Caribbean. They breed in the Pacific states of the U.S. and the extreme south east of Canada, Central Panama, the West Indies and the islands off Venezuela’s north coast. Being a partially migratory species, the most northerly populations migrate before winter to the southern U.S., northern Colombia, eastern Ecuador and northern Venezuela. It is a very adaptable wetland bird and will occupy almost any shallow water habitat within its geographical range. It is often found in swampy thickets, as it prefers to forage amongst dense vegetation, but when food is available it may feed out in the open.

Habits and lifestyle

Although they are quite common, Green herons are shy and so are not often observed. Their active period is during the day and they nest within their feeding areas. To catch fish they either stand in the water or perch low above the water, watching for prey, or they track it down. Occasionally they will swim after prey. They will retract their neck, holding their bill downwards aiming at a fish, take a few cautious steps and stab their prey with their bill. They feed either alone or as a pair. When threatened, alarmed or aggressive, Green herons raise their crest, hold their neck still and flutter their tail. They are territorial and do not tolerate intrusions. They attack intruders on sight, flying towards them, making a loud and guttural repetitive "annnck-annnnck". This call is also repeated as an alarm.

group name

sedge, seige, herd, battery, hedge, rookery

Diet and nutrition

Green herons are carnivores (piscivores and insectivores), they eat fish, insects, amphibians, crayfish, invertebrates, earthworms, leeches, dragonflies, grasshoppers, small rodents, lizards, snakes, frogs and tadpoles.

Diet

Mating habits

Green herons are serially monogamous, which means they mate with only one partner in a breeding season. The courtship display by the male is a circular flight similar to natural flight, but is directed towards the bird’s breeding area and accompanied by calls. The breeding season varies considerably in different geographic areas, generally beginning any time from March until July. Green herons nest either alone or in a loose groups. The male will protect the nest site during the construction of the nest. A pair builds a platform of sticks and stems, in trees or bushes, above or near water. 2 to 4 eggs are laid and incubation is by both parents, for about 21 to 25 days. The parents feed regurgitated food to the chicks, which begin hopping around their nest, snapping at insects after about 16 to 17 days when they are fledged. They gain independence at around 30 to 35 days. Chicks are dependent on their parents for about another month after fledging, reaching maturity at one year old.

Mating behavior

Reproduction season

varies geographically, generally in March-July

Incubation period

21-25 days

Independent age

30-35 days
hen

female name

cock

male name

chick

baby name

2-4 eggs

Clutch size

Population

Population Trend

Population status

ne
dd
lc
nt
vu
en
cr
ew
ex

Population threats

The Green heron used to be persecuted because it would forage at fish hatcheries; this may still happen today to some extent. It is possibly also possibly under threat due to the alteration of wetlands, as this can reduce breeding and foraging habitat. Further threats are contamination from pesticides, as well as disturbance from people using rivers for recreation.

Population number

The Green heron is common and widespread throughout its range but no overall population estimate is available. Currently this species is classified as Least Concern (LC) on the IUCN Red List, however, its numbers today are decreasing.

Ecological niche

Green herons have an important role in their aquatic habitat as predators of fish and invertebrates, controlling these populations.

Fun facts for kids

  1. The Green heron uses tools, being one of the few bird species to do so. It drops objects such as bread crusts, twigs, insects, earthworms, and feathers on the water’s surface to attract small fish.
  2. Due to its small size, a Green heron usually wades in shallow water, but it can dive in deeper water for prey and its partially webbed toes assist it to swim gracefully and effectively to shore.
  3. The Green heron belongs to a group of small herons that are considered sometimes as one species of Green-backed heron, which divides into the Green heron, the Galapagos heron and the Striated heron.
  4. A group of herons is called, amongst other things, a "battery", "hedge", "rookery", "pose", and "scattering" of herons."
  5. In flight, this heron looks like a crow, but its wing beats are slower, its neck is reddish-brown and its shape is slightly different.

References

  1. Green Heron Wikipedia article
    https://en.wikipedia.org/wiki/Green_heron
  2. Green Heron on The IUCN Red List site
    http://www.iucnredlist.org/details/22728182/0