Fairy Tern (Gygis alba) Nineteen of this species were observed on 12 February north of the Galapagos Islands in five small "flocks". Tern (sp.) (Sterninae) This was the third most abundant group in the survey area, with approximately 90 percent of the total occurring in Area A. This category is characterized by medium sized, Gray-backed Terns whose identification was precluded either by their distance from the observer and/or their presence in large, swirling flocks of mixed species.