Brown Pelican

http://bna.birds.cornell.edu/bna/species/609/articles/migration 

Migration

Nature Of Migration In The Species

Resident throughout almost entire breeding range, but segments of many populations undertake annual postbreeding migration.

Timing And Routes Of Migration

Along Atlantic coast of U.S., some initial northward dispersal after breeding, followed by southward migration in autumn. Annual summer visitor north of breeding range: in Delaware (since 1982), mid-May through late Aug or mid-Sep (Hess et al. 2000), and New Jersey (since 1980), early May through Oct (Walsh et al. 1999). Portions of N. and S. Carolina populations move south along Atlantic coast in Nov and Dec, winter mainly on east coast of Florida, then return north in Feb and Mar (Schreiber and Mock 1988). Most Virginia and Maryland birds presumably follow a similar route, exiting to the south by mid-Dec and returning to breeding areas in Apr and May (Iliff 1999a, 1999b). However, small numbers remain north to Cape Charles, VA, at least through late Dec (Christmas Bird Count data). Birds from Atlantic and Gulf coasts of Florida tend to remain on their respective coasts year-round, but may move farther south in response to onset of cold weather in late autumn and winter (Schreiber and Schreiber 1983, Schreiber and Mock 1988). Many adults and juveniles from U.S. Virgin Is. move westward after peak fall (Sep-Nov) breeding season and winter in Puerto Rico. Juveniles remain in Puerto Rican waters until they reach breeding age, while adults annually return to the Virgin Is. to breed (Collazo 1985). Postbreeding migration out of Gulf of California begins in Jun-Jul, earlier if nesting unsuccessful (Anderson and Anderson 1976). Most migrants cross Baja peninsula at its narrowest parts, most commonly at Bahia de los Angeles (D. Anderson pers. comm.), then move northward along Pacific coast as far as s. British Columbia. Birds from colonies in S. California Bight also migrate northward at end of their breeding season in Jul-Aug (Anderson and Anderson 1976). Numbers from s. California to s. British Columbia peak in Sep-Oct, then decline as in-dividuals return south to breeding areas by Dec-Jan (Briggs et al. 1981, 1983; Jaques 1994; Shepard 1999a, 1999b). Small proportion of Gulf of California population (mostly immatures) migrates inland to Sal-ton Sea, remains there through summer and autumn, then presumably returns to Gulf by Dec-Jan (Anderson et al. 1977a, Sturm 1998). Some migrants from Gulf of California move southward along Pacific coast of Mexico (Anderson 1983). Little known of migratory habits elsewhere in range.

Migratory Behavior

Little information. Remains within 10 km of shore during southward migration along California coast (Briggs et al. 1983). Makes use of thermals when crossing Baja peninsula (D. Anderson pers. comm.).

Control And Physiology

Little information. Southward migration along Atlantic coast of U.S. in autumn hypothesized to be response to onset of cold weather and reduced surface availability of fish (Schreiber and Mock 1988). Northward migration along Pacific coast of U.S. in late summer and autumn associated with seasonal warming period in California Current System and increased availability of prey (Anderson and Anderson 1976, Jaques 1994).


Recommended Citation

Shields, Mark. 2002. Brown Pelican (Pelecanus occidentalis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/609