Migration

Essentially resident, only “weakly” migratory, particularly among northern portions of breeding range in U.S. (Cooke 1913). Postbreeding dispersal occurs in late spring or summer and involves mostly immatures, with individuals now reported annually as far north as N. Carolina on Atlantic Coast and s. California on Pacific, and few vagrants even farther north to inland sites (see Appendix). Direct recoveries of birds banded in Texas indicate strong southward movement in Sep–Nov, with individuals occurring as far south as El Salvador and Guatemala. Movements of birds in West Indies poorly known, although Robertson (1978) suggested that white-morph birds occurring as far north as Florida Panhandle in summer might be from Cuban colonies. Nonbreeders summer in portions of winter range.

Postnesting dispersal occurs soon after immature independence. Recoveries of birds banded at Texas colonies, where nesting occurs primarily from Mar through Jun, indicate northward movement along coast between Jun and Sep, and southward flow thereafter: all direct recoveries between Oct and Feb south of banding localities (Paul 1991, RTP). In Florida, where some pairs nest from Nov to Feb and others from Feb to Jun, postbreeding dispersal occurs as early as Mar. With increase in nesting populations at Merritt I. and Tampa Bay in past 20 yr, greater numbers of egrets seen in summer along Eastern Seaboard and Florida Panhandle. Vagrants in ne. U.S. appear primarily May–Jul (see Appendix). Southward migration not detected in Florida, perhaps due to location of banding sites and difficulty in obtaining information from Cuba. Most records of vagrants in s. California between late Jul and early Jan, but records include all months of year; even 1 oversummering record for San Diego Co. (Small 1994). Present on Pacific coast of Costa Rica Sep–Apr (Ridgely and Gwynne 1989).

Most movement along coastlines. Occasional inland sightings suggest that species may ascend rivers. Banded individuals from Texas colonies found south to Oaxaca, Mexico (Bent 1926), with some apparently crossing Isthmus of Tehuantepec and wintering as far south as El Salvador (Paul 1991). Birds banded in s. Florida seen or recovered as far north as Merritt I. and Charlotte Harbor (RTP). Movements of birds from West Indian populations poorly known, but occasional sightings in Puerto Rico, Lesser Antilles, Cayman Is., Dry Tortugas, and Honduras to Panama at least indicate some interisland and coastal movements there (e.g., Ridgely and Gwynne 1989, Paul 1991).

Little known. Most reports of postbreeding dispersal or extralimital birds involve single birds or small numbers of individuals. In the Laguna Madre of Texas, tight flocks of 200–500 Reddish Egrets observed that appear migratory in nature (Allen 1955, Bolen and Cottam 1973, G. Unland pers. comm., RTP). This flocking unknown elsewhere, possibly because other populations smaller or less migratory.

No information.