Ardea herodias is widely distributed throughout North and Central America, extending into northern South America. It inhabits a wide variety of wetland environments, including marshes, swamps, rivers, lakes, estuaries, coastal lagoons, and mangrove forests, and is particularly common in shallow aquatic areas where fish are abundant. It is also regularly observed in man-made environments such as drainage ditches, aquaculture ponds, reservoirs, and even urban and suburban parks that feature water features or artificial wetlands. This species adapts well to both freshwater and saltwater ecosystems and can be found at elevations ranging from sea level to over 6,500 feet. Resident populations exist year-round in the southern U.S., Mexico, and parts of the tropics.

Known as the great blue heron, it is North America's largest heron species, reaching a height of up to 4.5 feet with a wingspan of around 6.5 feet and weighing between 4.5 and 5.5 pounds. It is recognized by its blue-gray body, long black plumes extending from the head, white face, and dagger-like yellow bill. In flight, it tucks its long neck into an “S” shape and displays slow, powerful wingbeats. It forages alone or in loose groups and uses a slow, deliberate stalking motion to catch fish, amphibians, insects, and small mammals. Hunting typically occurs during the early morning or late afternoon, although it will feed at night under moonlight. It breeds in colonies known as rookeries, often with other wading birds, building large stick nests in tall trees or shrubs near water. Clutches range from three to six eggs, and both parents participate in incubation and chick-rearing. The species has been observed to exhibit “bill dueling” and aggressive territorial displays during the nesting season. It is not considered endangered and is currently categorized as Least Concern by the IUCN, with global estimates exceeding 500,000 mature individuals. It can become accustomed to human presence in parks, golf courses, and marinas. The species is protected under the Migratory Bird Treaty Act in the United States and enjoys similar legal protections in Canada and other parts of its range.