The Great Blue Heron is the largest heron in North America , its full length is 97-137 cm, and its weight is 2.1-2.5 kg. The average wingspan is 213 cm. The wings are long, rounded. The beak is long, at the end has a conical shape, painted in light yellow. The tail is short. The legs are long, green. The neck is also long. The plumage in the upper body is gray, on the neck there are white, black and rusty-brown stripes. Males have a thick crest of black feathers on the back of their heads. Also, males are slightly larger than females.
Great Blue Heron is widespread in North and Central America , as well as in the West Indies and Galapagos Islands . In Russia, single specimens were observed on Ratmanova Island in the Bering Strait, although there are no reliable data on this score. Lives in most biomes with the exception of desert and highland territories.
As a rule, great blue herons breed only once a season. The breeding season usually lasts from March to May in the northern hemisphere and from November to April in the southern hemisphere. The female lays 2-7 pale blue eggs. Birds from more northern populations tend to lay more eggs. Both the male and the female participate in the incubation of eggs, alternating one after another. The incubation period lasts 26-30 days. Both parents feed the emerging chicks until they become able to fly, which takes about 2 months. Puberty of young birds occurs after 22 months.
The oldest known great blue heron lived 23 years, but most birds do not live up to this age. The average age limit of this species is estimated at 15 years. Like most other animals, they are most vulnerable in the first year of their life - during this period more than half die - about 69% of all birds.
These birds are most active in the morning and evening, when fish are well caught. They lead an individual lifestyle, preferring to hunt alone. However, they often nest in colonies, often with other species of herons, and in the daytime they sleep in groups of up to 100 birds. They have their own plot and aggressively guard their nest.
Great blue herons are much more water birds than our gray and red herons, they spend more time on water, can swim well and rarely sit on trees. The voice - a strong nasty scream similar to that of a gray heron - is heard very rarely.
In the north of the range, bird populations are migratory and migrate to the south of North America or the northern territories of South America for the winter.
Herons feed mainly on fish , but also eat frogs , salamanders , lizards , snakes , other birds, shrimp , crabs , lobsters , dragonflies , grasshoppers and many other aquatic insects . Herons peep out their prey in shallow water and usually swallow it whole. If the victim is too big, they first choke her.
Ravens and black ravens ( Corvus corax ) prey on the eggs of the great blue heron. Eagles , raccoons , bears , turkey vultures ( Cathartes aura ) and red-tailed buzzards ( Buteo jamaicensis ) attack the chicks and young birds.
Great Blue Heron forms 5 subspecies:
- A. h. herodias Linnaeus, 1758 - nominative subspecies; south of Canada, north-center and east of the USA south to North Carolina;
- A. h. fannini Chapman, 1901 - northwest of North America;
- A. h. wardi Ridgway, 1882 - west, south-center and south of the USA to northern Florida, western and north-eastern Mexico ;
- A. h. occidentalis Audubon, 1835 - South Florida and the Caribbean ;
- A. h. cognata Bangs, 1903 - Galapagos Islands .
