Community assemblages of migratory larids (Charadriiformes: Laridae) in southwestern Gulf of Mexico

Individuals of Laridae family play an important role in functional ecology of marine and coastal environments, and have been described as bioindicators of ichthyofauna, however, knowledge about these birds in southwestern Gulf of Mexico is limited. The objective of the present study was to study Laridae family assemblages and migratory patterns along Barra Norte beach coastline, Veracruz State, southwestern Gulf of Mexico. During 2014-2015 winter migratory season, three monthly samplings were conducted along 1 km x 600 m line transects. The assemblages were approached through diversity indices (Pielou’s equity, Simpson’s dominance and true diversity) and dominant species (characterized by a percentage similarity analysis). Migration was studied with a partial canonical correspondence analysis. A total of 3,314 organisms grouped into 14 species were recorded. Equity was highest in April and dominance in February. The dominant species were Leucophaeus atricilla, Thalasseus maximus, T. acuflavidus and Hydroprogne caspia. Three migratory patterns were found and coincide with the rainy, northerly and dry seasons. Each pattern contains particular species assemblages. The first pattern occurs from August to October 2014 (Sterna hirundo, T. acuflavidus and Chlidonias niger), the second from November 2014 to February 2015 (Larus delawarensis, L. californicus, L. argentatus smithsonianus, L. atricilla, H. caspia and Rissa trydactila) and the last one covers April and May 2015 (Rynchops niger, Sternula antillarum and L. pipixcan). Results establish that larids community assemblage is composed of a multiple migratory pattern.