With its long, white breeding plumes, orange-yellow bill, and green facial skin, the Great Egret at the height of the breeding season is stunning to behold. Even at other times of the year, when it loses its plumes and its face and bill return to their typical dull yellow, this large, white wader is difficult to overlook. Male and female Great Egrets are similar (38 inches) at all times of the year. The Great Egret is widely distributed across warmer parts of the globe. In North America, the Great Egret breeds primarily in the southeastern United States, with smaller pockets of breeding territory in the Great Plains, the northeast, and in the west. Most of the Great Egrets in the southeast are permanent residents, but those in cooler climates migrate south for the winter, where they may be found along the coast of California, in the southwest, and in Texas. This species also breeds in Eurasia from southern Europe east to east Asia, wintering in North Africa, India, and Southeast Asia. Populations also exist in South America, Australia and New Zealand. Great Egrets live in and around small bodies of water. In summer, Great Egrets nest in colonies, called ‘rookeries,’ in trees surrounding lakes and ponds. This species utilizes similar habitats during the winter. Great Egrets mainly eat fish, but may also take crustaceans and small vertebrates (such as frogs, lizards, and mice) when the opportunity arises. Great Egrets may be best observed wading in shallow water, where they may be seen plunging their bills into the water to catch fish. It is also possible to see Great Egrets at their rookeries, especially when they return to roost at sunset, or while flying with their feet extended and their necks pulled in. Great Egrets are primarily active during the day.

Threat Status: Least concern

Great egrets are found in the Nearctic as far south as Texas, the Gulf coast states, and Florida up the Atlantic coast to Maine and southern Canada, and west to the Great Lakes.

Biogeographic Regions: nearctic (Native )

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: in North America locally from southern Oregon and southern Idaho south through California, Nevada, and southwestern Arizona, and from southeastern Saskatchewan, southwestern Manitoba, central Minnesota, southwestern Wisconsin, central Illinois, southern Indiana, southern Ontario, northern Ohio, Vermont (probably), and Maine south through the Gulf states (and west to eastern Colorado, southern New Mexico, and south-central Texas), along both coasts of Mexico (interior locally), and through the Bahamas, Antilles, Middle America, and South America to southern Chile and southern Argentina. Widespread also in Old World. NORTHERN WINTER: occurs regularly north to North Carolina, southern U.S, and California; south through breeding range to southern South America; also Old World. In the U.S., areas with the highest winter densities include the Chassahowitzka NWR on the Gulf coast of Florida, the Sabine NWR on the coast near the Louisiana-Texas border, the southern Colorado River near the Imperial and Cibola refuges, and Humboldt Bay NWR in northern California (Root 1988). Wanders irregularly outside usual range; a few times to Hawaii.

Great egrets are found in the Nearctic as far south as Texas, the Gulf coast states, and Florida up the Atlantic coast to Maine and southern Canada, and west to the Great Lakes.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

In the continental United States, A. alba ranges from Oregon, Wisconsin and Massachusetts south to Florida, the Gulf of Mexico and most of South America. Occurs lagoon-wide

Great egrets are less than 1 meter long from bill to tail, are about 1 meter tall, and have a wingspan of about 1.5 meters. They usually weigh between 912 and 1140 grams. Males tend to be larger than females. They are white with a long yellow bill and with dark grey legs.

Range mass: 912 to 1140 g.

Average length: 1 m.

Average wingspan: 1.5 m.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger; ornamentation

Great egrets are less then 1 meter long from bill to tail, 1 meter tall, have a wingspan of 1.5 meters, and weigh about 912 to 1140 g. On average, males are larger than females. They are completely white with a long yellow bill and dark gray legs. During flight their neck is usually in an “S” shaped curve. They are very elegant birds with plumage resembling lace.

Range mass: 912 to 1140 g.

Average length: 1 m.

Average wingspan: 1.5 m.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger; ornamentation

Length: 99 cm

Weight: 935 grams

A. alba is one of the largest heron species. It grows to a height of 32 inches, and has a wingspan of 55 inches.

Differs from most other white herons in larger size (averages 23 cm longer than reddish egret, 38 cm longer than snowy egret), unicolored yellowish bill, and all-black legs and feet. Differs from the white form of the great blue heron in having black legs and feet (vs. yellowish).

Can be confused with the white morph of the great blue heron (Ardea herodias), the "great white heron", which occurs only in southern Florida. The great egret's black legs and feet distinguish it from the great white heron, which has yellow legs. Species Description/Taxonomy:Ardea alba is a member of the Order Ciconiiformes (herons and storks) which encompasses the long-necked wading birds. The Family Ardeidae includes the herons, egrets, bitterns, etc. A. alba is a large heron whose body color is entirely white. The bill is thick and yellow, while the legs and feet of the animal are black. When in breeding plumage, the great egret can appear somewhat shaggy due to the fine, threadlike feathers which grow downwards along the neck and back.

The ideal location for great egrets is near any form of water. Streams, lakes, ponds, mud flats, saltwater and freshwater marshes are inhabited by this beautiful bird. Wooded swamps and wetlands are the preferred location for great egrets and other heron species.

Habitat Regions: temperate ; terrestrial ; saltwater or marine ; freshwater

Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water

Wetlands: marsh ; swamp ; bog

Other Habitat Features: riparian ; estuarine

Habitat and Ecology

Systems

• Terrestrial
• Freshwater
• Marine

The ideal location for great egrets is near any form of water. Streams, lakes, ponds, mud flats, saltwater and freshwater marshes are inhabited by this beautiful bird. Wooded swamps and wetlands are the preferred location for great egrets and other heron species.

Habitat Regions: temperate ; terrestrial ; saltwater or marine ; freshwater

Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water

Wetlands: marsh ; swamp ; bog

Other Habitat Features: riparian ; estuarine

Depth range based on 4 specimens in 2 taxa.

Environmental ranges
  Depth range (m): 0 - 0
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Comments: Marshes, swampy woods, tidal estuaries, lagoons, mangroves, streams, lakes, and ponds; also fields and meadows.

Nests primarily in tall trees, usually with other colonial water birds; in woods or thickets near water. See Spendelow and Patton (1988) for further details and information on geographic variation in nesting habitat. Returns to the same colony sites year after year.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Migratory in north; extensive post-breeding dispersal occurs prior to southward migration (Palmer 1962). Some banded in the U.S. reach northern Colombia (recorded in September and November; Hilty and Brown 1986). Breeders from the U.S. Atlantic coast are thought to winter in the Bahamas and West Indies (see Byrd and Johnston 1991). Migrants from the north are present in Costa Rica October-April (Stiles and Skutch 1989).

Frogs, snakes, crayfish, fish, mice, crickets, aquatic insects, grasshoppers, and many other insects constitute the typical diet of a great egret. Other large wading birds have similar feeding habits and compete with great egrets for food resources.

As opportunistic predators, great egrets usually feed on smaller aquatic and terrestrial insects and vertebrates and are considered to be heterotrophs. Wading slowly through the water, they are extremely successful at striking and catching fish or insects. Studies found that, standing still, great egrets were able to ingest more prey of intermediate size than if they moved around. This suggests that their goal is not to catch the largest quantity of food, but to catch high quality food.

Animal Foods: mammals; amphibians; reptiles; fish; insects; aquatic crustaceans

Frogs, snakes, crayfish, fish, mice, crickets, aquatic insects, grasshoppers, and many other insects constitute the typical diet of a great egret. Other large wading birds have similar feeding habits and compete with great egrets for food resources.

As opportunistic predators, great egrets usually feed on smaller aquatic and terrestrial insects and vertebrates and are considered to be heterotrophs. Wading slowly through the water, they are extremely successful at striking and catching fish or insects. Studies found that, standing still, great egrets were able to ingest more prey of intermediate size than if they moved around. This suggests that their goal is not to catch the largest quantity of food, but to catch high quality food.

Animal Foods: mammals; amphibians; reptiles; fish; insects; aquatic crustaceans

Primary Diet: carnivore (Piscivore )

Comments: Eats mainly fishes, amphibians, snakes, snails, crustaceans, insects, and small mammals; commonly forages in marshes and shallow water of ponds, also in fields (Palmer 1962).

Great egrets are heterotrophs. They are opportunistic predators with a wide variety of prey species including fish, crustaceans, amphibians, small mammals, insects and reptiles. Miranda and Collazo (1997) found that great egrets feeding in South American lagoons ate primarily shrimp, followed by guppies, crabs and insects. In the Florida Everglades, great egrets prey primarily on fish (Smith 1997). Great egrets eat more large fish of more different species than do other wading birds. They thus have low dietary overlap with other heron and egret species. This can be partially attributed to their large size, which contributes to their ability to forage in deeper waters where they encounter more large fish than other species do. Great egrets can thus exploit a niche not open to smaller birds (Willard 1977). Another reason for lower dietary overlap with other wading birds is that great egrets are capable of adjusting their diets based on changing environmental conditions. When the amount of preferred prey in a habitat is decreased, great egrets alter their diets to include other prey species. This is different from patterns observed in other heron and egret species such as the snowy egret and tricolored heron, which alter their foraging habitat and feeding tactics in order to continue to encounter preferred prey (Smith 1997).Striking efficiency (the percentage of strikes which result in the capture and ingestion of prey) in great egrets is maximized when they feed while wading slowly through the water. However, Willard (1977) showed that great egrets capture and ingest more intermediate sized prey if they stand still while foraging. This finding suggests that the goal of most wading birds may not be to maximize feeding efficiency, but rather, to capture and ingest more high quality prey items.Smith (1997), in studying a nesting colony at Lake Okeechobee, Florida, found that the diets of great egret nestlings are among the most varied for wading birds, and includes as many as 40 different species. Mosquitofish were the primary prey items offered to nestlings, followed by crayfish, sailfin mollies, bluegills, and shad.Competitors: Other large wading birds such as the great blue heron utilize similar habitats and food resources, but probable resource partitioning among species minimizes direct competition.Habitats: Great egrets are sympatric with other species of wading birds. Willard (1977) and Kent (1986) found significant habitat overlap of great egrets with snowy egrets, tricolored herons and little blue herons. However, it appears that there is some level of habitat partitioning that occurs, with great egrets preferring to inhabit freshwater pools and lakes (Chavez-Ramirez and Slack 1995), while other species utilize estuarine habitats.In Florida, great egrets prefer habitats with high water levels in winter, followed by receding water levels in early spring (Smith and Collopy 1997). Recession of water in spring concentrates prey in a smaller area, helping to increase nest success, and the later foraging success of fledglings. Collopy and Smith (1995) have suggested this choice of breeding habitat has direct applications to wetland management around Lake Okeechobee. With the large numbers of wading birds nesting in this area, the authors suggest it could be most beneficial to bird populations for wetland managers to consider keeping lake levels low in the late winter or early spring months of the nesting season.

As predators great egrets affect the populations of their prey.

Adult great egrets have no non-human predators and now have some legal protection against humans. However, eggs and nestlings are exposed to numerous predators including crows (family Corvidae), vultures (family Cathartidae), and raccoons (Procyon_lotor, which are the most threatening).

Known Predators:

• jays and crows (Corvidae)
• vultures (Cathartidae)
• raccoons (Procyon_lotor)

As predators great egrets affect the populations of their prey.

Adult great egrets have no non-human predators and now have some legal protection against humans. However, eggs and nestlings are exposed to numerous predators including crows (family Corvidae), vultures (family Cathartidae), and raccoons (Procyon lotor, which are the most threatening).

Known Predators:

• jays and crows (Corvidae)
• vultures (Cathartidae)
• raccoons (Procyon lotor)

Great egrets are often seen in association with other wading birds in wetland habitat areas.

Ardea alba preys on:
Actinopterygii
Crustacea
Insecta
Amphibia
Reptilia
Mammalia

This list may not be complete but is based on published studies.

Casmerodius albus (Fish-eating birds) preys on:
Paralichthyes albigutta
Strongylura marina
Leiostomus xanthurus

Based on studies in:
USA: Florida (Estuarine)

This list may not be complete but is based on published studies.

Ardea alba is prey of:
Corvidae
Procyon lotor
Cathartidae

This list may not be complete but is based on published studies.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: > 300

100,000 to >1,000,000 individuals

Comments: See Spendelow and Patton (1988) for information on distribution and abundance of coastal U.S. breeding populations.

Great egrets are common in the IRL and throughout most of Florida.

Nonbreeding: may gather in groups but usually forages singly, spreading out over available area.

In Florida, nestlings infected by the nematode Eustrongylides ignotus experienced higher mortality rates than did uninfected nestlings (Spalding et al. 1994).

Great grets communicate through elaborate courtship rituals, and with vocalizations that are a harsh low “corr”. Much of the way these birds communicate is illustrated by their elaborate courtship dances, and territoriality. When defending their territory they may squawk harshly, leap at, or jab their beak at the intruder.

Communication Channels: visual ; tactile ; acoustic

Great grets communicate through elaborate courtship rituals, and with vocalizations that are a harsh low “corr”. Much of the way these birds communicate is illustrated by their elaborate courtship dances, and territoriality. When defending their territory they may squawk harshly, leap at, or jab their beak at the intruder.

Communication Channels: visual ; tactile ; acoustic

Comments: Arrives at roost at sunset or at dark, departs at first light (Palmer 1962). Forages during daylight (Powell 1987).

Nestlings are virtually helpless and covered with a layer of long white down feathers and begin to fly at about 42 days after hatching (Illinois Department of Natural Resources [INHS] 1998).

Nestlings are virtually helpless and covered with a layer of long white down feathers and begin to fly at about 42 days after hatching (Illinois Department of Natural Resources [INHS] 1998).

Great egrets have a lifespan of about 15 years in the wild (22 in captivity).

Range lifespan

Status: wild: 22.8 (high) years.

Average lifespan

Status: wild: 15 years.

Average lifespan

Status: captivity: 22 years.

Average lifespan

Status: wild: 274 months.

Great egrets have a lifespan of about 15 years in the wild (22 in captivity).

Range lifespan

Status: wild: 22.8 (high) years.

Average lifespan

Status: wild: 15 years.

Average lifespan

Status: captivity: 22 years.

Average lifespan

Status: wild: 274 months.

Maximum longevity: 22.8 years (wild)

Great egrets mate with one mate each season. Males are in charge of finding a home and attracting a female.

Mating System: monogamous

Great egrets usually build their nests around other egrets. Nests are a platform made of sticks, twigs, and stems built high up in a tree. Eggs are greenish blue, and both the male and female aid in hatching. Great egrets tend to lay 3-4 eggs. They raise one brood each year. Breeding season begins in mid-August.

Breeding interval: Great egrets breed once per year.

Breeding season: Breeding season begins in mid-April.

Average eggs per season: 3-4.

Average time to hatching: 23-24 days.

Average fledging age: 2-3 weeks.

Average age at sexual or reproductive maturity (female): 2 years.

Average age at sexual or reproductive maturity (male): 2 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization

Both males and females aid in incubating and feeding their young. Young nestlings are fed by regurgitation, which is when the parent eats food, and then pushes it back out of its mouth and down a baby's mouth. When the nestlings are a little older they will grab the food from their parent.

Parental Investment: no parental involvement; pre-fertilization; pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female)

Great egrets are seasonally monogamous animals. Male egrets are responsible for selecting a territory and performing a series of rituals in order to attract a female. Copulation occurs within the males’ territory.

Mating System: monogamous

Typically, great egret nests are built with other heron nests in a colony in wetlands and wooded swamps. Nests are a flimsy platform constructed of sticks, twigs, and stems built as high as possible. The eggs are a pale greenish blue, and are incubated by both the male and female for about 23 to 24 days. Nestlings usually fledge 2-3 weeks after hatching. With a clutch size of only 3-4 eggs, great egrets will lay replacement eggs if any of the first eggs are damaged. Great egrets are capable of reproducing after two years and raise one brood per year. The breeding season begins mid-April.

Breeding interval: Great egrets breed once per year.

Breeding season: Breeding season begins in mid-April.

Average eggs per season: 3-4.

Average time to hatching: 23-24 days.

Average fledging age: 2-3 weeks.

Average age at sexual or reproductive maturity (female): 2 years.

Average age at sexual or reproductive maturity (male): 2 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization

Both male and female great egrets participate in incubating and feeding the semi-altricial young. Nestlings are initially fed by regurgitation, followed by bill-grabbing, where the parent holds prey over the nestling to grab at as it eats.

Parental Investment: no parental involvement; pre-fertilization; pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female)

Clutch size is 1-6 (usually 3-4) in the north, 2-3 in the south. Incubation lasts 23-25 days, by both sexes. Young fly at about 6 weeks. Nests solitarily or in small to large colonies (Harrison 1979). In Florida, failure of nests was associated with high rainfall (Frederick and Collopy 1989). May lay another clutch if eggs are lost during incubation (Byrd and Johnston 1991).

Nesting in Florida's Lake Okeechobee region occurs from mid-December through January (Ehrlich et al 1988), and is preceded by courting behavior from as early as late July or August. Smith and Collopy (1995) found a strong positive correlation between receding water levels in Lake Okeechobee and nesting sites chosen by great egrets. It is believed that these areas are preferred because receding water has the effect of concentrating prey in a smaller area, thus making it simpler to feed nestlings (Smith and Collopy 1995). Between 3 - 5 eggs are laid per clutch. One brood is raised each year; however, should the first nest be destroyed, a replacement clutch can be laid.A study which followed a mixed nesting colony in Vero Beach, Florida reported that great egrets nesting along the Indian River Lagoon preferred to nest somewhat upland of the water's edge, constructing 77% of their nests in black mangrove trees; and 23% of nests in white mangrove trees (Maxwell and Kale 1977). In this study, most egg laying had been completed by the end of the first week of April.

The incubation period for great egret eggs is 23 - 26 days. Eggs hatch asynchronously over a period of several days. The first chick to hatch thus becomes the most experienced at food handling, and quickly becomes the most experienced aggressor toward its siblings. As a result, nestmates have varied growth rates, with the first chick generally growing the fastest. Data from Custer and Peterson (1991) show that first and second chicks have somewhat even growth rates, with third chicks showing slower growth.

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There are 8 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.


Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 15
Specimens with Barcodes: 23
Species With Barcodes: 1

Prior to the 20th century, the population of great egrets was nearly decimated by the demand for their lacey plumage for women’s hats and other fashionable garments. With great concern for the welfare of great egrets, legal restrictions were placed on the harvesting of this animal. Great egrets were placed under the protection of the Migratory Bird Treaty Act in 1918. By the mid 1900's populations of great egrets were steadily on the rise. Today, populations are doing well. However, there are still many human-induced threats to the survival of great egrets. Loss of habitat, water pollution, and various air pollutants all contribute to the dangers faced by great egrets. Hydrocarbons are especially problematic because they cause great egrets to lay thinner eggs that are more susceptible to cracking or damage before the young hatch. Mercury has been found at high levels in the feathers of numerous avian species including great egrets. The amount of mercury found depends on age, sex, geographic location, and mercury concentrations in the habitat around them including the air, soil and organisms they consume. These contaminations have also been found to negatively effect behavior, physiology, and reproduction.

IUCN Red List of Threatened Species: least concern

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

Regular passage visitor and winter visitor.

Prior to the 20th century, the population of great egrets was nearly decimated by the demand for their lacey plumage for women’s hats and other fashionable garments. With great concern for the welfare of great egrets, legal restrictions were placed on the harvesting of this animal. Great egrets were placed under the protection of the Migratory Bird Treaty Act in 1918. By the mid 1900's populations of great egrets were steadily on the rise. Today, populations are doing well. However, there are still many human-induced threats to the survival of great egrets. Loss of habitat, water pollution, and various air pollutants all contribute to the dangers faced by great egrets. Hydrocarbons are especially problematic because they cause great egrets to lay thinner eggs that are more susceptible to cracking or damage before the young hatch. Mercury has been found at high levels in the feathers of numerous avian species including great egrets. The amount of mercury found depends on age, sex, geographic location, and mercury concentrations in the habitat around them including the air, soil and organisms they consume. These contaminations have also been found to negatively effect behavior, physiology, and reproduction.

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N3B - Vulnerable

United States

Rounded National Status Rank: N5B,N5N : N5B: Secure - Breeding, N5N: Secure - Nonbreeding

Rounded Global Status Rank: G5 - Secure

Reasons: Secure due primarily to the very large range, though the amount of suitable nesting habitat is relatively restricted.

Population

Major Threats

In Florida, listed as a species of Species of Special Concern (SSC), but is not federally listed as threatened or endangered.Benefit in IRL: The environmental sensitivity of wading birds, coupled with the relative ease of assessing their numbers, makes them attractive as biological indicators of ecosystem health and habitat quality (Custer and Osborn 1977; Powell and Powell 1986; Powell et al. 1989).

Management Requirements: In Illinois, a public viewing area used once a week by humans 229 m from a rookery did not cause any overt responses from nesting birds (DeMauro 1993).

There are no known adverse affects of great egrets on humans.

Prior to the 20th century there was great demand for the lacey plumage of great egrets for women's hats and other fashionable garments.

Positive Impacts: body parts are source of valuable material

There are no known adverse affects of great egrets on humans.

Prior to the 20th century there was great demand for the lacey plumage of great egrets for women's hats and other fashionable garments.

Positive Impacts: body parts are source of valuable material

Comments: Formerly included in the genus Casmerodius (see AOU 1995). Has been included in genus Egretta by some authors (AOU 1998).