Great Blue Heron Ardea herodias

Ross G. Vennesland and Robert W. Butler
Version: 1.0 — Published March 4, 2020
Text last updated April 28, 2011


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Breeding Range

Widespread (Figure 1). The Great Blue Heron (Herodias group) nests as single pairs and small colonies along coasts of se. Alaska (61°N; M. Sigman pers. comm.) and n. British Columbia (Butler 1997). Mostly in colonies on south coast (Butler 1989) and mountain valleys of British Columbia, in central Canadian Prairies (Vermeer 1969d, Vermeer and Anweiler 1970, Vermeer 1973c, Vermeer and Anweiler 1970), s. Ontario (Gray et al. 1980, Dunn et al. 1985), s. Quebec (DesGranges et al. 1979), and the Canadian Maritime provinces (McAloney 1973, Quinney 1982), except Newfoundland (Montevecchi and Tuck 1987), south to Florida, Texas, Baja California, and Central America at least to Belize and Guatemala. Mostly in colonies and along the Pacific and Caribbean coast of Mexico to Guerrero (American Ornithologists' Union 1983, Howell and Webb 1995). Breeding status unknown in central Mexico.

The Occidentalis group (Great White Heron) is restricted to coastal habitats of s. Florida (including the Keys), Cuba, the Isle of Pines, St. Thomas, and Anegada (Hancock and Kushlan 1984). Formerly in Jamaica (Spendelow and Patton 1988). Great White Heron breeds on islands near Venezuela (Hancock and Kushlan 1984).

Recent updates include:

NY State (http://www.dec.ny.gov/cfmx/extapps/bba/bbaMaps.cfm?bndcode=GBHE&year=2000) (2000-2005): species is widespread.

Ontario (http://www.birdsontario.org/atlas/maps.jsp?lang=en): breeding concentrated in the southeast, and Lake of the Woods region; scattered nesting as far north as 53°N.

Québec (DesGranges 1996): confirmed breeding as far north as 50°N; concentrations in the southwest (St. Lawrence Basin) and on the Magdalen Islands.

Maritime Provinces (http://www.mba-aom.ca/jsp/map.jsp?lang=en): widespread but primarily coastal, especially e. coast of Nova Scotia and s. New Brunswick.

Alberta (Fed. Alberta Nat. 2007): scattered nesting confirmed throughout southern half of province, with concentration in region in and around Lakeland Provincial Park.

Manitoba (http://www.mba-aom.ca/jsp/map.jsp?lang=en ): scattered breeding in southern third (roughly) of the province, with few confirmed locations.

Saskatchewan (Smith 1996, Hanson 2000): Widespread in southern half of province (south of ca. 50°N).

Texas (http://txtbba.tamu.edu/accounts/gtbh/gtbhacc.html): primarily coastal, but found breeding throughout the state, especially eastern half.

Mexico (Howell and Webb 1995): Dark- (Blue-) morph herons fairly common but local breeders (sea level to 2000 m) in nw. Mexico south to Sinaloa, and on the Atlantic slope from Tamaulipas to the Yucatan Peninsula; white morph herons local breeders in coastal northern and eastern Yucatan.

Hispaniola (Latta et al. 2006): scattered local breeder, island-wide; mostly costal areas – including offshore islands -- especially near river mouths.

Cuba (Garrido and Kirkonnell 2000): island-wide, especially coastal; few/no data on breeding locations, or on differing distribution of white vs. blue morphs; needs study.

Venezuela (Hilty 2003): rare and local as a breeder; only know to breed on Esparquí I. in Los Roques group: 20% white, 20% blue (“gray”) and white; 60% blue (“gray”).

Great Blue Heron breeds on the Galapagos Islands (Harris 1973).

Winter Range

Pacific coast south of 61°N (Williamson et al. 1965) through Central America, and mostly south of Canada and midwest U.S. states (Figure 1). Includes the islands and coast of the Caribbean south to Colombia (Hancock and Kushlan 1984). But note that Parkes (1998) reported an occurrence for Brazil. Former casual in winter in Venezuela and Colombia (Byrd 1978c, Hancock and Kushlan 1984); stragglers recorded on Hawaiian Islands (Berger 1972b).

In Mexico (Howell and Webb 1995), fairly common throughout, up to 2500 m. On Hispaniola, band returns suggest an influx of non-breeders in winter months from the north (Latta et al. 2006).

Extralimital Records

Lewington et al. (1991) note the species is accidental in the Azores, with ca. 10 birds observed April 1984 on 3 islands, some staying until June. One individual landed on an east-bound ship in the North Atlantic, October 1968; stayed aboard for days. Immature at Asturias, Spain, Dec-Feb 1989.

Distribution of the Great Blue Heron
  • Year-round
  • Migration
  • Breeding
  • Non-Breeding
Distribution of the Great Blue Heron
Great Blue Heron, Abundance map
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Data provided by eBird

Great Blue Heron

Ardea herodias


This map depicts the seasonally-averaged estimated relative abundance, defined as the expected count on an eBird Traveling Count starting at the optimal time of day with the optimal search duration and distance that maximizes detection of that species in a region.  Learn more

Relative abundance
Breeding season
May 10 - Jun 28
Non-breeding season
Dec 28 - Jan 25
Pre-breeding migratory season
Feb 1 - May 3
Post-breeding migratory season
Jul 6 - Dec 21
Note: Seasonal ranges overlap and are stacked in the order above; view full range in season maps.
Seasons timeline
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Recommended Citation

Vennesland, R. G. and R. W. Butler (2020). Great Blue Heron (Ardea herodias), version 1.0. In Birds of the World (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.grbher3.01