Family Herons (Ardeidae)

Least Concern

Great Blue Heron (Ardea herodias)


French: Grand Héron German: Kanadareiher Spanish: Garza azulada
Other common names: Great White Heron (white morph)

Ardea herodias


, 1758,

America = Hudson Bay, Canada


Closely related to A. cinerea and A. cocoi; in the past, sometimes considered conspecific with former. Race occidentalis, mostly white-morph birds, previously considered a distinct species. Possible hybrid occidentalis × wardi with white head, described as different species, Würdemann’s Heron (A. wurdemanni); recent opinion suggests that it is merely a colour morph of wardi or occidentalis. Older proposed forms treganzai, hyperonca and sanctilucae are all synonymized with wardi#R. Five subspecies recognized.

Subspecies and Distribution
  • A. h. fannini Chapman, 1901 – SE Alaska to coastal Washington (NW USA).
  • A. h. wardi Ridgway, 1882 – SW Canada and W USA S to NW Mexico; N populations winter S to N Central America.
  • A. h. herodias Linnaeus, 1758 – S Canada (Alberta E to Nova Scotia) S through C & E USA to E Mexico (S to Tabasco); winters S to West Indies, Central America and NW South America.
  • A. h. occidentalis Audubon, 1835 – S Florida and Yucatán Peninsula through West Indies to islands off N Venezuela.
  • A. h. cognata Bangs, 1903 – Galapagos Is.
  • Descriptive notes

    91–137 cm; 1750–3629 g; wingspan 170–190 cm. Fundamentally allopatric A. cocoi (in S South America) and A. cinerea (of Eurasia) are... read more


    Gives harsh, deep “frawnk” in alarm, when disturbed, taking flight and aggression, but this call is... read more


    Habitat generalist: river and lake margins, wet meadows, marshes, swamps, fields, also sewage ponds... read more

    Food and feeding

    Fish, including pike (Esox lucius), as well as Micropterus and Lepomis, up to 30 cm, and smalltooth bass up to... read more


    Feb–May in most of North America including most of Mexico, and Cuba, but continuing until Aug; year-round in Florida, peak in Dec... read more


    Marked post-breeding dispersal in North America, especially in NC of continent, mainly in Sept... read more

    Status and conservation

    Not globally threatened (Least Concern). Common and apparently stable in North America since 1930s, with 8016 breeding birds counted along US Atlantic coast in 1976, and 4000... read more

    Recommended citation

    Martínez-Vilalta, A., Motis, A. & Kirwan, G.M. (2020). Great Blue Heron (Ardea herodias). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 22 February 2020).