Both male and female Great Egrets take turns incubating their eggs and brooding their young (Wiese 1975 in McCrimmon et al. 2001).
The Great Egret is known to occur in ten counties in New York State (New York Breeding Bird Atlas 2000-2005, New York Natural Heritage Program 2007). The population peaked in 1975 at 410 breeding pairs, during a period of fluctuation, and then reached a stable population by 1988 (Peterson 1988 cited in Andrle and Carroll 1988). New York's Great Egret population has been growing steadily since the first breeding attempt in 1953. The abundance of breeding birds on Long Island has nearly tripled since 1985 and the breeding popualtion has expanded its range both northward to Lake Champlain and eastward to the Niagara River. The greatest former threat of hunting has been essentially eliminated and productivity losses and mortality from pollution, contamination and habitat loss seem to be low enough to allow for population expansion (McGowan and Corwin 2008). The sizeable, growing population, high number of occurrences and threats that are not impinging on popualtion expansion contributed to the S4 rank for this egret. The rank was calculated using the Element Rank Estimator, version 6.03.
Brown et al. (2001) discovered that there were approximately 28 nesting pairs of Great Egrets on Jamaica Bay Wildlife Refuge beginning in 1974. The number of nesting pairs on Long Island was found to decline slightly during the 1970s, as was true for most wading birds, and increase during the 1990s (Brown et al. 2001). The first Breeding Bird Atlas in New York (1980-1985) reported Great Egrets in 21 probable or confirmed breeding blocks (Andrle and Carroll 1988). The second Atlas (2000-2005) reported them in 39 breeding blocks (New York State Breeding Bird Atlas 2000-2005). The species is also found in the Lake Erie and Lake Champlain Basins (McCrimmon 2006, New York Natural Heritage Program 2007) and the statewide population of Great Egrets in recent years appears to be stable (Peterson cited in Andrle and Carroll 1988) with an increase in recent years (New York State Breeding Bird Atlas 2000-2005).
Beginning in the late 1800s, the Great Egret was only an occasional summer visitor in New York. During this time frame and the early 1900s, Great Egrets were nearly extirpated in the state due to overhunting for their plumes, which were in high demand for hats. Since the Migratory Bird Treaty Act's protection, the birds became regular visitors and began to establish breeding populations by the early 1960s in Suffolk County. In 1975, the population reached its peak, and after a period of fluctuation in the 1970s and 1980s, the species maintains a stable population in New York (Peterson 1988 cited in Andrle and Carroll 1988).
Habitat loss has been noted as the greatest threat to this species. In addition, complete information on breeding and foraging habitat requirements is not currently available (McCrimmon 2006). On Long Island, threats include flooding, erosion, human activity, and predation. Human activities include boating, dredge spoil deposition, pedestrians, jet skiers, ORV and other vehicle use, development, oil spills, contaminants, vandalism, and invasive species. Known predators that currently pose a threat to populations are crows, gulls, fox, raccoons, dogs, feral cats, rats, and others (New York Natural Heritage Program 2007).
As habitat loss is the largest known threat to Great Egrets, continuing to protect lands such as the Jamaica Bay Wildlife Refuge and other managed areas is important to the conservation of this species and other colonial waterbirds (Brown et al. 2001). Limiting predation and human activity through the use of predator exclosures, visitor education, and by posting restricted signs in breeding and foraging areas would also be beneficial. Any habitat restoration efforts should consider increasing the availability of pool and open water habitat, as foraging habitat availability may be a limiting factor for egrets (Trocki and Paton 2006). Another consideration for the management of breeding Great Egrets is the use of buffers around colonies to reduce flushing responses to human disturbance (Peters and Otis 2006). Vehicle disturbances, especially in undeveloped areas, have been shown to cause a decline in foraging rates for this species, with seasonal differences in behavioral response (Stolen 2003, Traut and Hostetler 2003). This suggests that buffer zones could provide additional protection.
Further studies are needed to understand how this species is affected by habitat loss from human activity. While many existing and potential threats have been identified, further knowledge about how these threats interplay and affect Great Egret behavior and population viability would better inform management decisions (Peters and Otis 2006). More complete information on breeding and foraging habitat requirements is needed for this species as well (McCrimmon 2006).
Great Egrets inhabit marshes, open riverbanks, irrigation canals, and lakeshores in New York (Budliger and Kennedy 2005). They nest on coastal islands and barrier beaches on Long Island in dense scrub thickets or trees (New York Natural Heritage Program 2007).
The Great Egret is confirmed from locations in ten counties across New York State (New York Breeding Bird Atlas 2000-2005, New York Natural Heritage Program 2007). Populations in Long Island/Metropolitan New York appear stable, and the species' range has expanded in recent years to include the Lake Erie and Lake Champlain Basins (McCrimmon 2006).
The Great Egret is known to breed in North America locally from southern Oregon and southern Idaho south through California, Nevada, and southwestern Arizona. It is also known from southeastern Saskatchewan, southwestern Manitoba, central Minnesota, southwestern Wisconsin, central Illinois, southern Indiana, southern Ontario, northern Ohio, Vermont (probably), and Maine. It is known to occur from 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. It is also widespread in the Old World (Nature Serve 2007). Northern wintering grounds include areas north to North Carolina, the southern United States and California and south through the breeding range to southern South America. It also winters in the Old World. In the United States, areas with the highest winter densities include the Chassahowitzka National Wildlife Refuge (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 cited in Nature Serve 2007). Great Egrets may occur irregularly outside their usual range, and have been observed a few times in Hawaii (Nature Serve 2007).
The Great Egret is a large, white heron that is 94-104 cm in length, has a wingspread of 140 cm, and body mass of 1kg (Handcock and Kushlan 1984 cited in McCrimmon et al. 2001). Other defining features include long, black legs and feet, a long neck, and a long, straight, yellow bill (NGS 1983 cited in Nature Serve 2007). During breeding season, long, white plumes trail from the throat and the rump (Budliger and Kennedy 2005). Great Egrets are known to nest in colonies with others of the same species or other waterbird species (Nesbitt et al. 1982 and Spendelow and Patton 1988 cited in McCrimmon et al. 2001). Nests are placed high in trees and shrubs (McCrimmon et al. 2001). Some nests are located on the ground but most are 4-12 feet above the ground. The clutch size is 1-6 eggs, with 3-4 eggs more common in northern climates; incubation is 23-25 days, and young fledge at about 6 weeks (Harrison 1979 cited in Nature Serve 2007). Eggs are a pale blue-green (Budliger and Kennedy 2005). Common vocalizations include a rapid, low-pitched "cuk-cuk-cuk" (Budliger and Kennedy 2005) and other low croaks such as a gravelly "kroow" and a grating "karrr" (Sibley 2000).
Great Egrets eat fishes, amphibians, snakes, snails, crustaceans, insects, and small mammals. Fish species Carassius auratus, Cyprinus carpio, and Notropis sp. are among the most common in their diet in Lake Erie (Hoffman 1978 cited in McCrimmon et al.2001). Great Egrets are stand-and-wait predators (Budliger and Kennedy 2005) and their foraging habitat includes marshes, shallow water of ponds, and fields (Palmer 1962 cited in Nature Serve 2007).
They breed from May through June on Long Island (Budliger and Kennedy 2005). They are rare in NY before April and after November.
The time of year you would expect to find Great Egret active and reproducing in New York.
Ardea alba Linnaeus, 1758
American Ornithologists' Union (AOU). 1983. Check-list of North American Birds, 6th edition. Allen Press, Inc., Lawrence, Kansas. 877 pp.
American Ornithologists' Union (AOU). 1995. Fortieth supplement to the American Ornithologists' Union Check-list of North American Birds. Auk 112:819-30.
Andrle, Robert F. and Janet R. Carroll, editors. 1988. The atlas of breeding birds in New York State. Cornell University Press. 551 pp.
Brown, K.M., J.L. Tims, R.M Erwin, and M.E. Richmond. 2001. Changes in the nesting populations of colonial waterbirds in Jamaica Bay Wildlife Refuge, New York, 1974-1998. Northeastern Naturalist 8(3): 275-292.
Budliger, R.E., and G. Kennedy. 2005. Birds of New York State. Lone Pine Publishing, Auburn, WA. 384pp.
Bull, John. 1974. Birds of New York State. Doubleday, Garden City, New York. 655 pp.
Byrd, M. A., and D. W. Johnston. 1991. Birds. Pages 477-537 in K. Terwilliger, coordinator. Virginia's endangered species: proceedings of a symposium. McDonald and Woodward Publ. Co., Blacksburg, Virginia.
DeMauro, M. M. 1993. Colonial nesting bird responses to visitor use at Lake Renwick heron rookery, Illinois. Natural Areas Journal 13:4-9.
Fleury, B. E., and T. W. Sherry. 1995. Long-term population trends of colonial wading birds in the southern United States: the impact of crayfish aquaculture on Louisiana populations. Auk 112:613-632.
Frederick, P. C., and M. W. Collopy. 1989. Nesting success of five ciconiiform species in relation to water conditions in the Florida Everglades. Auk 106:625-634.
Harrison, H. H. 1979. A field guide to western birds' nests. Houghton Mifflin Company, Boston. 279 pp.
Hilty, S.L. and W. L. Brown. 1986. A Guide to the Birds of Colombia. Princeton University Press, Princeton, USA. 836 pp.
Illinois Fish and Wildlife Information System. 1987. Species book. great egret.37 pp.
McCrimmon, D.A. 2006. Species group report for colonial nesting herons. Pages 33-42 of Appendix A1, Species group reports for birds in: New York State comprehensive wildlife conservation strategy. New York Department of Environmental Conservation. Albany NY.
McCrimmon, D.A., Jr., J.C. Ogden, and G.T. Bancroft. 2001. Great Egret (Ardea alba). In The Birds of North America, No. 570 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA. Available at http://bna.birds.cornell.edu/bna/species/570/articles/introduction (Accessed: October 26, 2007).
National Geographic Society (NGS). 1983. Field guide to the birds of North America. National Geographic Society, Washington, DC.
NatureServe. 2007. NatureServe Explorer: An online encyclopedia of life [web application]. Version 6.1. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. (Accessed: October 26, 2007).
New York Natural Heritage Program. 2007. Biotics Database. Albany, NY.
New York Natural Heritage Program. 2020. New York Natural Heritage Program Databases. Albany, NY.
New York State Breeding Bird Atlas 2000 [Internet]. 2000 - 2005. Release 1.0. Albany (New York): New York State Department of Environmental Conservation. [updated 2007 Jun 11; cited 2007 Dec 08]. Available from: http://www.dec.ny.gov/animals/7312.html.
New York State Breeding Bird Atlas. 1985. Final breeding bird distribution maps, 1980-1985. New York State Department of Environmental Conservation, Wildlife Resources Center. Delmar, NY.
New York State Department of Environmental Conservation. 2005. Comprehensive Wildlife Conservation Strategy Planning Database. New York State Department of Environmental Conservation. Albany, NY.
New York State Department of Environmental Conservation. Checklist of the amphibians, reptiles, birds, and mammals of New York State, including their protective status. Nongame Unit, Wildlife Resources Center, Delmar, NY.
Palmer, R. S. (editor). 1962. Handbook of North American birds. Vol. 1. Loons through flamingos. Yale University Press, New Haven. 567 pp.
Payne, R. B., and C. J. Risley. 1976. Systematics and evolutionary relationships among the herons (Ardeidae). Univ. Michigan Mus. Zool., Misc. Publ. No. 150. 115 pp.
Peters, K.A. and D.L. Otis. 2006. Wading bird resonse to recreational boat traffic: does flushing translate into avoidance? Wildlife Society Bulletin 34(5): 1383-1391.
Powell, G.V.N. 1987. Habitat use by wading birds in a subtropical estuary: implications of hydrography. Auk 104:740-749.
Pratt, H. D., P. L. Bruner, and D. G. Berrett. 1987. A Field Guide to the Birds of Hawaii and the Tropical Pacific. Princeton University Press, Princeton, New Jersey. 409 pp. + 45 plates.
Raffaele, H. A. 1983a. A guide to the birds of Puerto Rico and the Virgin Islands. Fondo Educativo Interamericano, San Juan, Puerto Rico. 255 pp.
Root, T. 1988. Atlas of wintering North American birds: An analysis of Christmas Bird Count data. University of Chicago Press. 336 pp.
Sibley, D. A. 2000a. The Sibley guide to birds. Alfred A. Knopf, New York.
Spalding, M. G., J. P. Smith, and D. J. Forrester. 1994. Natural and experimental infections of EUSTRONGYLIDES IGNOTUS: effects on growth and survival of nestling wading birds. Auk 111:328-336.
Spendelow, J. A. and S. R. Patton. 1988. National Atlas of Coastal Waterbird Colonies in the Contiguous United States: 1976-1982. U.S. Fish and Wildlife Service, Biological Report 88(5). x + 326 pp.
Stiles, F. G. and A. F. Skutch. 1989. A guide to the birds of Costa Rica. Cornell University Press, Ithaca, New York, USA. 511 pp.
Stolen, E.D. 2003. The effects of vehicle passage on foraging behavior of wading birds. Waterbirds 26(4): 429-436.
Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.
Traut, A.H. and M.E. Hostetler. 2003. Urban lakes and waterbirds: effects of development on avian behavior. Waterbirds 26(3): 290-302.
Trocki, C.L. and P.W.C. Paton. 2006. Assessing habitat selection by foraging egrets in salt marches at multiple spatial scales. Wetlands 26:307-312.
Information for this guide was last updated on: December 10, 2008
Please cite this page as:
New York Natural Heritage Program. 2020. Online Conservation Guide for Ardea alba. Available from: https://guides.nynhp.org/great-egret/. Accessed September 27, 2020.