Great Egret (Ardea alba) in Puerto Rico

How to recognize a Great Egret

Look for a tall white heron with a very long S-curved neck, a straight dagger-like yellow bill, and black legs and feet. It is only slightly smaller than a Great Blue Heron and nearly twice as tall as a Cattle Egret. In breeding season it carries long, fine ornamental plumes on the back, and the bill can darken a little.

Three common mix-ups: Snowy Egret has a black bill and yellow feet; Cattle Egret is short, short-billed, and lives in pastures; and the white form of Great Blue Heron, called Great White Heron, is bigger, heavier-billed, and pale-legged, and is known mainly from Florida. Black legs plus a yellow bill almost always means Great Egret.

Where to see it in Puerto Rico

Great Egret uses fresh and saltwater ponds, canals, mangroves, lagoons, wet pastures, and even urban streams. It is easy in coastal wetlands: the San Juan lagoons, Piñones, Humacao Nature Reserve, Laguna Cartagena, the Cabo Rojo salt flats, and Jobos Bay. In the eBird and iNaturalist data aggregated by GBIF, it is the most-reported heron around the San José and Torrecilla lagoons.

For a good look, go early and scan open shorelines, since it forages in exposed places: lake edges, large marshes, and shallow estuaries. Most records are from the lowlands, but the atlas also documented nesting in the subtropical wet forest life zone of the mountains, so it can turn up at interior reservoirs and rivers.

What it eats and how it hunts

It eats mostly fish, but also crustaceans, frogs, lizards, snakes, aquatic insects, and occasionally grasshoppers and rodents. Its technique is patience: it stands or walks very slowly in shallow water, waits for prey to come close, and catches it with a fast thrust of the bill.

That calm sets it apart from Snowy Egret, which runs and stirs the bottom with its feet, and from Reddish Egret, which leaps and spreads its wings. If you find a big white heron frozen for minutes at a lagoon edge, wait for the final strike: it is one of the easiest behaviors to photograph in the island's wetlands.

Nesting and colonies

Great Egret nests and roosts in colonies, often mixed with other herons. It builds a loose stick platform on a branch or shrub, typically 10 to 40 feet above ground or water, and lays 3 to 4 pale blue-green eggs that hatch after 23 to 26 days.

Published Caribbean accounts gave April to June for nesting, but the Puerto Rico atlas found most activity in March, April, and May. Of the hexagons with breeding evidence, 47% were in subtropical moist forest, 40% in subtropical dry forest, and 13% in subtropical wet forest. Only 7% of the area with breeding evidence was protected, so a known colony deserves respect and distance.

Names: Great Egret, Garza Real, Egretta alba

In Puerto Rico its local name is Garza Real. Elsewhere it is called garceta grande, garza blanca, or garza blanca grande, and in Spain garza real refers to Ardea cinerea, a gray heron. When comparing guides from different countries, always confirm the scientific name.

That scientific name has changed too. Today it is Ardea alba, but older publications list it as Egretta alba or Casmerodius albus. A search for egretta alba or ardea alba is about the same species. In English it has also been called common egret, large egret, or great white egret.

The plumes that nearly wiped it out

In the late nineteenth and early twentieth centuries, Great Egret breeding plumes decorated women's hats, and hunting at colonies pushed it close to disappearing from North America. Early conservationists stopped the hunting and protected colonies, and the egret became the symbol of the National Audubon Society.

Today its range is enormous and the IUCN lists it as Least Concern, but in Puerto Rico it depends on wetlands that get filled, polluted, or drained. To watch it without harm, stay on shorelines or trails, keep away from trees with nests, and avoid flying drones over colonies during nesting season.

What is Ardea alba?

It is the Great Egret, called Garza Real in Puerto Rico: a large white heron, 89 to 104 cm long, with a yellow bill and black legs. In Puerto Rico it is a common native resident of wetlands, lagoons, and mangroves, and it is not threatened.

Are Great Egret and Egretta alba the same species?

Yes. Egretta alba and Casmerodius albus are older scientific names for the same species, now classified as Ardea alba.

When does the Great Egret nest in Puerto Rico?

The 2004–2009 atlas found most breeding activity in March, April, and May. It nests in colonies on stick platforms in trees or shrubs near water and lays 3 to 4 eggs.

Where can I see a Great Egret in Puerto Rico?

In almost any lowland wetland: the San Juan lagoons, Piñones, Humacao Nature Reserve, Laguna Cartagena, the Cabo Rojo salt flats, and Jobos Bay. The atlas recorded it in 53% of surveyed hexagons.

How do I tell a Great Egret from a Snowy Egret?

Great Egret is much larger, with a yellow bill and legs black to the toes. Snowy Egret is 56 to 66 cm, with a black bill, yellow face, and yellow feet.

Does the Great Egret make any sound?

It is usually quiet. When disturbed it gives a low, hoarse croak, and at colonies it makes loud croaks and higher squawks. You can hear recordings on its species page.