SCIENTIFIC NAME:
Egretta rufescens (Gmelin)
OTHER NAMES:
None.
STATUS:
Breeder. Uncommon in spring, summer, and fall in Gulf Coast region. HIGH CONSERVATION CONCERN.
DESCRIPTION:
An intermediate-sized (76 cm [27-30 in.]) heron smaller than the great egret, but larger than the similar little blue heron. Color phases include dark adults that are deep reddish-chestnut brown on head and neck and slaty blue on body, and light adults that are all white. Adults in breeding plumage have long plumes on back, shaggy plumes on head and neck, black-tipped bills with a bright pink base, violet lores, cobalt blue legs, and black feet. At other times adults have bicolored, dark-tipped bill with a light base, and blackish legs and feet. Dark phase immatures paler than adults, appearing gray-blue with some pale cinnamon on the head, neck, and inner wing (Palmer 1962, Paul 1991). During breeding season, low guttural raaahcalls are given during threat displays and soft crog-crog calls may be exchanged between displaying adults (Palmer 1962). Three subspecies described: the nominate eastern North American and West Indian race, E. r. rufescens, the more western, E. r. dickeyi, and the Central American, E. r.colorata (Palmer 1962). However, validity of those other than the nominate race questionable (Paul 1996).
DISTRIBUTION:
Breeds along coasts of Texas, Louisiana, Alabama, southern Florida, Mexico, Belize, and the West Indies. Winter distribution similar to breeding distribution, but north to southwestern California (rarely) and Atlantic Coast to Delaware (occasionally), and south to Costa Rica and Venezuela. Occasionally occurs inland, especially after breeding (AOU 1998).
HABITAT:
Occurs almost exclusively along coastal lagoons, beaches, and estuaries; rarely away from saline environments. Prefers shallow water-foraging areas, usually less than 15 centimeters (six inches) deep (Paul 1996). Nesting typically occurs on natural islands, or man-made dredge material disposal islands and occasionally on the coastal mainland (Paul 1991). Prefers nesting in mangrove or structurally similar habitats such as Brazilian pepper, mesquite, huisache, sea oxeye, sea purslane, and Spanish bayonet.
FEEDING HABITS: Feeds on fish. Foraging areas include saline, hypersaline, or brackish coastal habitats including barren sand or mud tidal flats, salt ponds, lagoons, and open mangrove communities (Paul 1991, Stevenson and Anderson 1994). Will occasionally feed in other habitats including coastal beaches, the shores of lakes and reservoirs, and sparsely vegetated freshwater marshes (Paul 1991).
LIFE HISTORY AND ECOLOGY:
Nesting generally occurs in mixed wading bird colonies, but individuals may nest alone or in small groups apart from other waders (Paul 1996). Both sexes build a platform nest composed of sticks that is usually less than three meters (nine feet) above ground or water. However, nests can be constructed on ground among low vegetation, bare sand, or shell ridges or as high as six meters (18 feet) (Paul 1991, Stevenson and Anderson 1994). Birds typically aggregate into nesting colonies by February-March and most eggs laid between mid-March and mid-April (Paul 1991); however, egg-laying can begin as late as mid-June, and second clutches may occur as late as mid-July (Simersky 1971). In FloridaBay, nesting occurs virtually year-round. In the Carribean, nesting is generally winter-summer, but can occur year-round (Paul 1991). Clutch size usually three to four eggs and both sexes incubate for an average of 26 days. After hatching, adults brood the young for another three weeks and feed young by regurgitation for an additional six weeks (Paul 1991). Renesting attempts are not as successful as first nesting attempts (Simersky 1971). Most do not breed until three to four years old, however, a few individuals mature when two years old (Paul 1991, 1996). Relatively long-lived and, based on banding data, known to live at least 11 years. Preliminary data suggest that birds return to their natal colonies (Paul 1991). Extremely active feeders, using spread wings and rapid steps to secure primarily small fish (Palmer 1962).
BASIS FOR STATUS CLASSIFICATION:
Nearly driven to extinction by plume hunters between the late 1800s and mid-1930s and still has not recovered. In Florida, was virtually extirpated by 1890 and was reportedly not seen between 1927 and 1937. The population in FloridaBay recovered from total extirpation in 1935 to 200 to 250 adults in late 1970s. However, the population changed little by 1980s. Recent analyses of Christmas Bird Count data show a nonsignificant decline survey-wide 1959-1988. Has declined significantly in Texas, while increasing significantly in Florida over same period (Sauer et al. 1996). Current United States population estimated at roughly 2,000 pairs (Paul 1996), with about three-quarters of those occurring in Texas. Primary causes for recent concern about the species include habitat loss due to coastal development, dredging operations, and hydrological alterations (Paul 1991, 1996); pesticide contamination, particularly DDT and PCB; disturbance to foraging and nesting birds from increased human recreational activities in coastal habitats; and predation on adults, juveniles, and eggs by a host of predators (Paul 1991, 1996). Although species seems to be recovering slowly, the priority designation in Alabama is based on low relative abundance over entire distribution (PIF 2002), occurrence in restricted habitats particularly vulnerable to development, and increasing impacts by human recreational activities.
Author:
C. Dwight Cooley
