[order] CICONIIFORMES | [family] Ardeidae | [latin] Ardea herodias | [authority] Linnaeus, 1758 | [UK] Great Blue Heron | [FR] Grand Heron | [DE] Kanadareiher | [ES] Garza Azulada | [NL] Amerikaanse Blauwe Reiger
Subspecies
Monotypic species
Genus
Best known of the typical herons are the very large, long-legged and long-necked, plain-hued, crested members of the genus Ardea The species of the Ardeidae (heron) family are mainly tropical birds, but they have spread out all over the world and occupy all but extremely high latitudes and elevation. Most members of this almost worldwide group breed colonially in trees, building large stick nests. Northern species such as Great Blue, Grey and Purple Herons may migrate south in winter, although the first two do so only from areas where the waters freeze. These are powerful birds with large spear-like bills, long necks and long legs, which hunt by waiting motionless or stalking their prey in shallow water before seizing it with a sudden lunge. They have a slow steady flight, with the neck retracted as is characteristic of herons and bitterns; this distinguishes them from storks, cranes, and spoonbills, which extend their necks
Physical charateristics
Great blue herons are the largest herons in North America. They stand approximately 60 cm tall and are 97 to 137 cm long. They weigh 2.1 to 2.5 kg. They have long, rounded wings, long bills that taper to a point at the end, and short tails. They also have very long necks and legs. The bills are a yellowish color and the legs are green. Great blue herons have gray upper bodies, and their necks are streaked with white, black and rust-brown. They have grey feathers on the back of their necks with chestnut colored feathers on their thighs. The males have a puffy plume of feathers behind their heads and also tend to be slightly larger than females.
Listen to the sound of Great Blue Heron
[audio:http://www.planetofbirds.com/MASTER/CICONIIFORMES/Ardeidae/sounds/Great Blue Heron.mp3]
Copyright remark: Most sounds derived from xeno-canto
| wingspan min.: | 145 | cm | wingspan max.: | 155 | cm |
| size min.: | 85 | cm | size max.: | 100 | cm |
| incubation min.: | 26 | days | incubation max.: | 30 | days |
| fledging min.: | 58 | days | fledging max.: | 30 | days |
| broods: | 1 | eggs min.: | 2 | ||
| eggs max.: | 7 |
Range
North America, Middle America : widespread
Habitat
Great blue herons always live near sources of water, including rivers, lake edges, marshes, saltwater seacoasts, and swamps. They usually nest in trees or bushes that stand near water, breeding at elevations of up to 1,500 m. They tend to avoid marine habitats along the east coast and instead live inland.
Reproduction
Great blue herons typically breed from March to May in the northern part of their range and November through April in the southern hemisphere. Females lay between 2 and 7 pale blue eggs. Birds living further north tend to have more eggs. Both parents incubate the eggs, which means that the parents take turns sitting on the nest to keep the eggs warm until they hatch. The eggs hatch after 26 to 30 days of incubation. After living in the nest for about 2 months, the babies (called chicks) are ready to fledge, which means they are old enough to leave the nest and survive on their own. Herons become sexually mature when they are about 22 months of age. Both parents care for and feed the chicks until they are ready to leave the nest. The largest chicks receive the most food.
Feeding habits
Great blue herons fish in both the night and the day, with most of their activity occurring around dawn and dusk. Herons use their long legs to wade in shallow water and their sharp “spearlike” bills to catch their food. Great blue herons’ diet consists of mainly fish, but also includes frogs, salamanders, lizards, snakes, birds, small mammals, shrimps, crabs, crayfish , dragonflies, grasshoppers, and many other aquatic insects. Herons locate their food by sight and usually swallow it whole. Herons have been known to choke on prey that is too large.
Video Great Blue Heron
httpv://www.youtube.com/watch?v=61mWc9B8dlc
copyright: Bill Wayman
Conservation
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be small, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Great blue herons can be found in the Nearctic and Neotropical regions. During the spring and summer, they breed throughout North and Central America, the Caribbean, much of Canada and the Galapogos. Some populations migrate to Central and South America during the winter months, but do not breed there.
Great blue herons can be found in the Nearctic and Neotropical regions. During the spring and summer, they breed throughout North and Central America, the Caribbean, much of Canada and the Galapogos. Some populations migrate to Central and South America during the winter months, but do not breed there.
Migration
Marked post-breeding dispersal in N America. Populations of N migratory, those of S sedentary, sometimes with local movements. Autumn migration takes birds to S USA, Cuba, West Indies, C America and N parts of S America, though some birds winter as far N as S Canada. Accidental to Greenland; Hawaii, Azores. White morph sedentary, with some wandering and post-breeding dispersal.
Distribution map
Literature
Title Nest Site Characteristics of Great Blue Herons (Ardea herodias) in
Northeast Ohio
Northeast Ohio
Author(s): BECKY A. CARLSON and John Carroll
Abstract: Seventeen Great Blue Heronries were surveyed in ni..[more]..
Source: OHIO J. SCI. 95 (5): 312-315, 1995
Title Predation of Eared Grebe by Great Blue Heron
Author(s): James W. Rivers and Michael J. Kuehn
Abstract: Great Blue Herons (Ardea herodias)
typically prey..[more]..
typically prey..[more]..
Source: The Wilson Journal of Ornithology 118(1):112-113, 2006
Title Eustrongylides and Pesticide Levels in a Great Blue Heron Shot in Wisconsin
Author(s): D . M . Swinefordi
Abstract: The parasitic roundworm, Eustrongylides ignotus [a..[more]..
Source: Patuxent Wildlife Research Centeri
Title Factors Influencing Great Blue Heron Nesting Productivity
on the Pacific Coast of Canada from 1998 to 1999
on the Pacific Coast of Canada from 1998 to 1999
Author(s): ROSS G. VENNESLAND AND ROBERT W. BUTLER
Abstract: Surveys were conducted at 35 Great Blue Heron (Ard..[more]..
Source: Waterbirds 27(3): 289-296, 2004
Title ?PRACTICE? FORAGING BY A SUB-ADULT GREAT BLUE HERON
Author(s): WILLIAM E. DAVIS, JR.
Abstract: ?Play?, including ?practice? aggression and foragi..[more]..
Source: Florida Field Naturalist 29(3):88-89, 2001.
Title Retrobulbar teratoma in a great blue heron (Ardea herodias)
Author(s): Scott H. Schelling
Abstract: At presentation to the Vermont Institute of Natura..[more]..
Source: J Vet Diagn Invest 6:514-516 (1994)
Title Aerial plunge foraging by a Great Blue Heron
Author(s): STEVEN R . MOREY and ALLAN SMITS
Abstract: This report describes the environmental context
a..[more]..
a..[more]..
Source: Wilson Bull., 99(2), 1987, pp. 293-294
Title DIRECTIONS AND TIMING OF GREAT BLUE HERON FORAGING FLIGHTS FROM A CALIFORNIA COLONY:
IMPLICATIONS FOR SOCIAL FACILITATION OF FOOD FINDING
IMPLICATIONS FOR SOCIAL FACILITATION OF FOOD FINDING
Author(s): HELEN M. PRATT
Abstract: Patterns of foraging trips of several species of c..[more]..
Source: Wilson Bull., 92(4), 1980, pp. 489-496
Title Utilizing the great blue heron (Ardea herodias)
in ecological risk assessments of bioaccumulative
contaminants
in ecological risk assessments of bioaccumulative
contaminants
Author(s): Rita Marie Seston, Matthew John Zwiernik ET AL.
Abstract: Selection of an appropriate species is
a key elem..[more]..
a key elem..[more]..
Source: Environ Monit Assess
Title REPRODUCTIVE SUCCESS OF GREAT BLUE HERONS
(ARDIA HERODIAS) NESTING IN SWANSON CREEK, MARYLAND
DURING THE CHALK POINT OIL SPILL
(ARDIA HERODIAS) NESTING IN SWANSON CREEK, MARYLAND
DURING THE CHALK POINT OIL SPILL
Author(s): unknown
Abstract: On April 7, 2000, approximately 126,000 gallons of..[more]..
Source: unknown
Title COMPARISON OF TECHNIQUES FOR CENSUSING GREAT BLUE HERON NESTS
Author(s): JAMES P. GIBBS et al.
Abstract: A comparison of the accuracy of different techniqu..[more]..
Source: J. Field Ornithol., 59(2):130-134
Title Evidence from nature: interspecies spread of heron
hepatitis B viruses
hepatitis B viruses
Author(s): Li Lin, Alexej Prassolov et al.
Abstract: Heron hepatitis B viruses (HHBVs) in three subspec..[more]..
Source: Journal of General Virology (2005), 86, 1335-1342
Title GREAT BLUE HERON DEATHS CAUSED BY PREDATION ON PACIFIC LAMPREY
Author(s): BLAIR 0. WOLF and STEPHANIE L. JONES
Abstract: Encounters between predator and prey commonly lead..[more]..
Source: The Condor 91:482-484