Nesting Sites and Population Estimates of Seabirds and other Waterbirds of the Gulf of Chiriquí, Panamá

—Little information exists on nesting by seabirds and coastal waterbirds in Panamá. The present study of the Gulf of Chiriquí complements our previous study of nesting waterbirds of the Gulf of Panamá. In April 2012, about 4,000 nests of seven species of seabirds and other colonial waterbirds were identified during a complete survey by small plane and boat within and adjacent to the Gulf of Chiriquí. Seventeen colony sites were found, 12 of which are reported here for the first time. Nesting species included Brown Booby (Sula leucogaster; the most abundant species with nearly 2,500 nests), Brown Pelican (Pelecanus occidentalis), Magnificent Frigatebird (Fregata magnificens), Bridled Tern (Onychoprion anaethetus; second nesting site for Panamá), Wood Stork (Mycteria americana; third nesting site for Panamá), Great Egret (Ardea alba), and Cattle Egret (Bubulcus ibis). The largest nesting site in the Gulf of Chiriquí was the Islas Ladrones, with 2,200 Brown Booby nests (the largest site for this species in Panamá) and 130 Magnificent Frigatebird nests. Unlike most of the sites found in this study, these islands are not currently officially protected. Received 17 April 2014, accepted 22 June 2014.