What Do We Know About Black Skimmers? A Review on Its Annual-Cycle and Life-History Main Events

Abstract

The Black Skimmer Rynchops niger is a New World's coastal migratory bird with three subspecies based on distinctive morphometrics, plumage, and breeding distribution. Its population is decreasing in North America while numbers are poorly known in South America. Here we conducted an extensive review of the literature on the Black Skimmer to fill gaps in the knowledge of each subspecies' natural history and suggest where future research should focus. We used 41,247 records collected from databases and literature to establish the overall occurrence and location of breeding colonies for each subspecies. We also collected information on the phenology of life-history events described in 150 papers and books to compare the annual cycle of the three subspecies. The North American subspecies R. n. niger breeds, migrates and stages along the coast with few records inland. The South American R. n. intercedens and Amazonian R. n. cinerascens subspecies breed inland and migrate mostly to coastal staging sites. The pre...