The great heron (Ardea herodias) is a large wading bird found throughout much of North America. Herons live and breed near calm freshwater and saltwater habitats like marshes, swamps, rivers, lakes, estuaries, tidal flats, ponds, and coastal wetlands. They are most active at dusk and dawn when they feed. During the day they often rest or roost near water.
Quick Facts
Here are some quick facts about where great herons live:
- Great herons are found throughout much of North America from southern Canada to Mexico, and on Caribbean islands.
- They inhabit freshwater and saltwater wetlands and waterways including marshes, swamps, tidal flats, ponds, rivers, lakes, and estuaries.
- Herons nest and breed in trees, bushes, or patches of vegetation near water sources.
- They build large stick nests high up in trees to protect eggs and young from predators.
- Herons roost and rest during the day near water on branches, stumps, or vegetation.
- Northern populations migrate south in winter, while some southern birds are permanent residents year-round.
- On the coast, herons utilize intertidal areas like mudflats to feed at low tide.
Distribution Across North America
The great heron has a wide distribution across much of North America from southern Canada down through the United States, Mexico, and Caribbean islands. Here is more detail on where they can be found in different regions:
Canada
In Canada, the great heron breeds from British Columbia east to Newfoundland. Its range extends across southern Canada from the Pacific to Atlantic coasts. The southern parts of the Prairie Provinces mark the northern limits of its breeding range.
United States
Throughout the contiguous United States, the great heron can be found year-round or seasonally in every state except Hawaii. It breeds in every state except Montana, Wyoming, and the Dakotas where it is only a migrant.
Mexico
In Mexico, great herons are permanent residents along both the Pacific and Gulf Coasts. They occur along the coasts of Baja California, the mainland west coast, and throughout the Gulf Coast region.
Caribbean
In the Caribbean, the great heron is a year-round resident on islands including Cuba, Jamaica, Hispaniola, Puerto Rico, and the Bahamas. It is also found on other islands further south along the Caribbean coastlines.
Typical Great Heron Habitats
Great herons occupy a variety of wetland and coastal habitats. Here are some of their preferred habitats:
Freshwater Marshes
Freshwater marshes with shallow, calm water and abundant vegetation are prime habitat. Herons stalk through the marsh and along vegetation edges looking for fish, frogs, insects, and other prey.
Swamps
Forested swamps and flooded timber offer ideal habitat. Herons hunt among the waterways and standing dead trees for fish and amphibians.
Ponds
Farm ponds, retention ponds, and small lakes provide excellent foraging and nesting habitat.
Rivers and Streams
Slow-moving rivers, streams, oxbows, sloughs, and backwaters are frequented by herons. The trees along riverbanks are used for nesting and roosting.
Estuaries
Herons forage along estuaries where rivers meet the sea. The gradient between the freshwater and saltwater makes for excellent feeding habitat.
Intertidal Zones
Herons hunt on exposed intertidal mudflats and tidal creeks at low tide to catch fish and invertebrates.
Saltwater Marshes
Coastal salt marshes rich in fish, crabs, and marine life are inhabited by herons year-round and during migration.
Mangrove Swamps
In tropical areas, mangrove swamps are important habitat. Herons walk along the snag roots and hunt in pools during high and low tides.
Breeding Habitat
Herons nest in trees or patches of dense vegetation near water sources where they feed. Here are details on their breeding habitat preferences:
- Herons build large, flat nests high up in the canopy of live trees or in dead snags.
- They usually nest in colonies with other wading birds for protection from predators.
- Tree species used include cypress, mangroves, pine, sycamore, willow, and many others depending on region.
- Nests are also built in thickets of bushes, bamboo, or reeds closer to wetlands.
- Range of nest heights is 10-150 feet high depending on tree size and type.
- Coastal habitats like mangroves and marshes are preferred in tropical areas.
- The presence of prey like fish, amphibians, and crustaceans is key when choosing nest sites.
Roosting and Resting Habitat
During the day when not actively feeding, herons rest and roost near waterways in trees and vegetation:
- Herons roost solitarily or in loose groups called “heronries.”
- Thick vegetation and tall trees provide cover and protection while resting.
- Branches overhanging the water are preferred roosting spots.
- Living trees and dead snags are both used for daytime roosts.
- Mangroves, cypress, pine, and willow are examples of tree species used for roosting.
- In coastal areas, herons rest on jetties, pilings, breakwaters, and sand bars.
- Roost sites are typically close to feeding areas.
Habitat Availability Drives Distribution
The availability of suitable wetland feeding areas and nesting sites determines where herons live. Some key factors about heron habitat use include:
- Year-round ranges depend on permanent waterways that don’t freeze in winter.
- Migratory patterns are tied to seasonal availability of feeding and nesting habitat.
- Loss of wetlands through drainage and development has reduced habitat in some regions.
- Conservation of marshes, swamps, and coastal wetlands preserves crucial habitat.
- Creation of artificial wetlands provides new habitat in some areas.
- Prey availability in aquatic areas is vital for heron survival and reproduction.
Understanding what specific wetland habitats herons rely on can guide conservation efforts so these iconic birds continue thriving across their range.
Conclusion
In summary, the great heron inhabits a variety of wetland habitats across most of North America. It feeds in calm, shallow freshwater and saltwater areas like marshes, swamps, ponds, tidal flats and estuaries. Herons nest high up in trees adjacent to feeding areas. During the day they rest and roost in trees and vegetation near waterways. The availability of suitable aquatic habitat and nest sites determines their distribution and migratory patterns. Protecting and managing essential wetland ecosystems will ensure great herons continue to grace these watery habitats for generations to come.
