| 词条 | Little blue heron |
| 释义 |
| status = LC | status_system = IUCN3.1 | status_ref = [1] | image = Egretta caerulea -Cananeia, Sao Paulo, Brasil-8.jpg | genus = Egretta | species = caerulea | authority = (Linnaeus, 1758) | range_map = Egretta caerulea map.svg | range_map_caption = Distribution of Egretta caerulea:{{leftlegend|yellow|breeding|outline=gray}}{{leftlegend|blue|non-breeding|outline=gray}}{{leftlegend|green|year-round|outline=gray}} | synonyms = Ardea caerulea {{small|Linnaeus, 1758}} }} The little blue heron (Egretta caerulea) is a small heron. It breeds in the Gulf states of the US, through Central America and the Caribbean south to Peru and Uruguay. It is a resident breeder in most of its range, but some northern breeders migrate to the southeastern US or beyond in winter. There is post-breeding dispersal to well north of the nesting range, as far as the Canada–US border. DescriptionThis species is about {{convert|60|cm|abbr=on}} long, with a {{convert|102|cm|abbr=on}} wingspan, and weighs {{convert|325|g|abbr=on}}. It is a medium-large, long-legged heron with a long pointed blue or greyish bill with a black tip. Breeding adult birds have blue-grey plumage except for the head and neck, which are purplish and have long blue filamentous plumes. The legs and feet are dark blue. The sexes are similar. Non-breeding adults have dark blue head and neck plumage and paler legs. Young birds are all white except for dark wing tips and have dull greenish legs. They gradually acquire blue plumage as they mature. EcologyThe little blue heron's breeding habitat is sub-tropical swamps. It nests in colonies, often with other herons, usually on platforms of sticks in trees or shrubs. Three to seven light blue eggs are laid. The little blue heron stalks its prey methodically in shallow water, often running as it does so. It eats fish, frogs, crustaceans, small rodents and insects. White little blue herons often mingle with snowy egrets. The snowy egret tolerates their presence more than little blue herons in adult plumage. These young birds actually catch more fish when in the presence of the snowy egret and also gain a measure of protection from predators when they mix into flocks of white herons. It is plausible that because of these advantages, they remain white for their first year.[2] == References == 1. ^{{IUCN|id=22696944 |title=Egretta caerulea |assessor=BirdLife International |assessor-link=BirdLife International |version=2013.2 |year=2012 |accessdate=26 November 2013}} 2. ^{{cite web|url=http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Little_Blue_Heron.html#coolfacts|title=Little Blue Heron|publisher=}}
External links{{Commons category|Egretta caerulea|Little blue heron}}{{Wikispecies|Egretta caerulea}}
5 : Egretta|Wading birds|Native birds of the Southeastern United States|Birds of the Americas|Birds described in 1758 |
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