Diet of Common Terns in the Azores, Northeast Atlantic

We studied the diet of the Common Tern (Sterna hirundo) in several islands of the Azores during 1994, based on the analysis of 777 food pellets. The diet of Common Terns was based on a few species of small pelagic fish. Trumpet Fish (Macroramphosus spp.) dominated the diet in terms of both frequency of occurrence (84%) and numerical frequency (69%). This species, together with Boarfish (Capros aper), Blue Jack Mackerel (Trachurus picturatus) and lantern fish (Families Myctophidae, Sternoptychidae, Diretmidae), accounted for more than 96% of the prey taken by Common Terns on all the islands. Insects occurred in 10% of all pellets analyzed and were present in almost 15% of the pellets from Corvo. Lantern fish represented an important fraction of the diet of Common Terns in the Azores and included several species previously undescribed as prey of seabirds in the region. Comparisons with dietary data obtained in subsequent years showed little inter-annual variability in the frequency of abundance of ...