Little Gull Hydrocoloeus minutus Scientific name definitions

Editor's Note: Based on genetic and morphological data, the Little Gull is now placed in its own genus, Hydrocoloeus. Future revisions of this account will adjust for this change.

The smallest gull worldwide, the Little Gull breeds in small numbers in North America but its main range is in the Palearctic. It now occurs regularly in small numbers along the eastern seaboard of the United States and on the Great Lakes, and it appears to breed mostly in the Great Lakes basin and in Canadian wetlands further north, usually near Common Tern (Sterna hirundo), Black Tern (Chlidonias niger), Forster's Tern (Sterna forsteri), or Ross's Gull (Rhodostethia rosea). Although numbers are generally increasing in North America, few breeding locations are known.

The origin of the Little Gull in North America is something of a mystery. Some think that the species has always occurred here, albeit in small numbers. Others believe that it colonized via the Bering Sea, while many support the idea of one or more transatlantic colonizations from western Europe (reinforced by the recent return of a Swedish-banded chick in its first summer in Pennsylvania). The first documented nesting of this species in North America was not until 1962, on Lake Ontario, although the first recorded continental record was in 1819–1820, on the Franklin expedition (Houston 1998a Houston, C. S. (1998a). "List of new species added to North American natural history 1820-1827 by Surgeon/naturalist John Richardson. Appendix." In Sir John Franklin's journals and correspondence: the second arctic land expedition., edited by R. C. Davies. Toronto: Champlain Society. Close ). As of 1999, only 67 confirmed and probable nestings have been documented in North America, and these have occurred mainly in wetlands in the Great Lakes–St. Lawrence River basin, and the lowlands of Hudson and James Bays.

In North America the species is most frequently observed during winter and on migration in groups of 1–3, usually associated with larger flocks of Bonaparte's Gull (Chroicocephalus philadelphia) along coasts or at larger inland lakes and rivers, although loose flocks of ≥100 have been recorded along the U.S. east coast and on the Great Lakes. Migration routes within North America are poorly known. The diet appears to consist mostly of small fish, invertebrates and some flying insects, but remarkably little ecological information exists for this species outside of Europe.

There have been no major biological studies of this species in North America. This account of its life history has collated all readily available published observational notes, regional bird atlases and unpublished records, and draws heavily on detailed studies in northwestern Europe of breeding and behavior (Veen 1980 Veen, J. (1980). Breeding behaviour and breeding success of a colony of Little Gulls Larus minutus in the Netherlands. Limosa 53:73-83. Close , Veen 1985 Veen, J. (1985). On the functional significance of long call components in the Little Gull. Netherlands Journal of Zoology 35:63-86. Close , Veen and Piersma 1986 Veen, J. and T. Piersma. (1986). Causation and function of different vocal reactions of Little Gulls Larus minutus to intruders near the nest. Behaviour 96:241-264. Close , Veen 1987 Veen, J. (1987). Ambivalence in the structure of display vocalizations of gulls and terns: new evidence in favour of Tinbergen's conflict hypothesis? Behaviour 100:33-49. Close ), distribution and migration (Hutchinson and Neath 1978 Hutchinson, C. D. and B. Neath. (1978). Little Gulls in Britain and Ireland. British Birds 71:563-582. Close , Smith 1987d Smith, P. H. (1987d). The changing status of Little Gulls Larus minutus in north Merseyside, England. Seabird 10:13-21. Close , Messenger 1993 Messenger, D. (1993). Spring passage of Little Gulls across Northern England. British Birds 86:397-406. Close ), and the detailed species account presented by Cramp and Simmons (Cramp and Simmons 1983 Cramp, S., and K. E. L. Simmons (1983). The Birds of the Western Palearctic, Volume 3: Waders to Gulls. Oxford University Press, Oxford, UK. Close ). The main published North American papers are mostly from Canada, dealing with breeding records, distribution, and comments on possible origins (Baillie 1963 Baillie, J. L. (1963). Three bird immigrants from the Old World. Trans. R. Can. Inst. 34:95-105. Close , Mcrae 1984 Mcrae, R. D. (1984). First nesting of the Little Gull in Manitoba. American Birds 38:368-369. Close , Mcrae 1989 Mcrae, R. D. (1989). Little Gull: immigrant or elusive resident? Seasons 29:44-45. Close , Weseloh 1994 Weseloh, D. V. (1994). "A history of the Little Gull in Ontario, 1930-1991." In Ornithology in Ontario., edited by M. K. McNicholl and J. L. Cranmer-Byng, 240-259. Ontario: Hawk Owl Publ., H. F. and G. Witherby. Close ).