Blue Heron (Ardea herudias)
481 views · Published 25 February 2012 · 1:18 · Indexed 21 September 2026
Channel: Alan Heath · 2012 · Pets & Animals
https://www.facebook.com/pages/Alan-Heaths-History-Page/173472422695696 http://www.ceepackaging.com twitter : @ceepackaging https://www.facebook.com/pages/CEE-Packaging/135108923181666 The blue heron is the largest North American heron. It has head-to-tail length of up to 140cm, a wingspan of up to two metres and a height of up to 140cms and can weigh 2.5 kg. The call is a harsh croak. The heron is most vocal during the breeding season, but will call occasionally at any time of the year in territorial disputes or if disturbed as here in this film. It is found throughout most of North America, as far north as Alaska and the southern Canadian provinces. The range extends south through Florida, Mexico and the Caribbean to South America. Birds east of the Rocky Mountains in the northern part of their range are migratory and winter in Central America or northern South America. From the southern United States southwards, and on the Pacific coast, they are year-round residents. However, individuals often remain through cold northern winters, as well. The primary food for the Blue Heron is small fish, though it is also known to opportunistically feed on a wide range of shrimp, crabs, aquatic insects, rodents and other small mammals, amphibians, reptiles, and small birds. Herons locate their food by sight and usually swallow it whole. Herons have been known to choke on prey that is too large. It is generally a solitary feeder. Individuals usually forage while standing in water, but will also feed in fields or drop from the air, or a perch, into water. As large wading birds, they are able to feed in deeper waters, and thus are able to harvest from niche areas not open to most other heron species. It feeds in shallow water or at the water's edge during both the night and the day, but especially around dawn and dusk. It uses its long legs to wade through shallow water, and spears fish or frogs with its long, sharp bill. This species usually breeds in colonies, in trees close to lakes or other wetlands. Often such colonies include only Blue Herons, sometimes they nest alongside other species of herons. These groups are called heronry (a more specific term than "rookery"). The size of these colonies may be large, ranging between 5--500 nests per colony, with an average of approximately 160 nests per colony. They build a bulky stick nest, and the female lays three to six pale blue eggs. One brood is raised each year. If the nest is abandoned or destroyed, the female may lay a replacement clutch. Reproduction is negatively affected by human disturbance, particularly during the beginning of nesting. Repeated human intrusion into nesting areas often results in nest failure, with abandonment of eggs or chicks. Both parents feed the young at the nest by regurgitating food. Parent birds have been shown to consume up to four times as much food when they are feeding young chicks than when laying or incubating eggs. Eggs are incubated for around 28 days and hatch asynchronously over a period of several days. The first chick to hatch usually becomes more experienced in food handling and aggressive interactions with siblings, and so often grows more quickly than the other chicks. Predators of eggs and nestlings include turkey vultures, several corvids, hawks, bears and raccoons, the latter two also potential predators of adults. Adult herons, due to their size, have few natural predators, but can be taken by Bald Eagles, Golden Eagles and, less frequently, Great Horned Owls and Red-tailed Hawks. When predation on an adult or chick occurs at a breeding colony, the colony can be abandoned by the other birds, but this does not always occur. It can be found in a range of habitats, in fresh and saltwater marshes, mangrove swamps, flooded meadows, lake edges, or shorelines, but always close to bodies of water, usually nesting in trees or bushes.
