Santa Maria is the most easterly island in the Azores and has a 75km long coastline. The proposed IBA is 386 km2 in size and covers the coastal waters surrounding the whole island, to a maximum distance of 10km and including the marine areas adjacent to terrestrial IBAs PT068, PT069 and PT070. Nationally, this is one of the IBAs where breed the largest number of species qualifying for marine IBA classification, which shows how important it is. The Common Tern, with around 620 pairs, breeds and uses the IBA almost exclusively. TheVila islet and Adjacent Coast SPA, which is inside the IBA, has colonies of Roseate Tern, Common Tern, Yellow-legged Gull, Little Shearwater, Bulwer's Petrel, Madeiran Storm-petrel and Cory's Shearwater. In fact, the only breeding colony of Bulwer's Petrel known in the Azores is here, with a population of around 50 pairs.
Cory's Shearwater Calonectris diomedea: This is the most abundant species at Santa Maria, with a population of around 16,000 birds (DOP-IMAR UAç). Tracking work on Cory's Shearwaters involving data-loggers indicates that the birds on the Vila islet use only the IBA when exhibiting "raft" behaviour", and that around 75% of fishing events on short trips occur within this area. Little Shearwater Puffinus assimilis: The Vila islet is the only place in the Azores with nests of this species located in accessible places (only around 20). Individual tagging campaigns were carried out on this species in 2007, which should yield knowledge on the feeding areas of this species, present in Azores waters during the better part of the year. Bulwer's Petrel Bulweria bulwerii: The Vila islet is the only breeding place known for this species in the Azores, giving shelter to around 50 pairs (Monteiro et al. 1999, Bried and Bourgeois 2005). Since 2002, these pairs are monitored every year, which will enable a description of the demographic parameters of this population. Madeiran Storm-petrel Oceanodroma castro: since 2002, the pairs at the accessible nests have been monitored every year using capture-tagging-recapture, which will enable a description of the demographic parameters of this population and a modelling of its dynamics. Yellow-legged Gull Larus cachinnans: There are 1 to 3 pairs of Yellow-legged Gulll on Vila island. Roseate Tern Sterna dougallii: This IBA has a population estimate of 390 breeding pairs. Vila island is the most important colony in the IBA, in terms of numbers and regularity, with around 250 pairs. However, the colonies called "Baia do Cura", on the eastern part of the island, also have many breeding pairs. Common Tern Sterna hirundo: The survey carried out in 2007 indicated a total population of 620 pairs, with the Vila islet as the largest colony in the area of the proposed IBA at 200 breeding pairs (Neves 2007). Black Tern Sterna fuscata: Vila islet seems to be the only place in the Azores where the Black Tern occurs regularly, and breeding by one or two couples on Vila islet has been known since 1990 (Monteiro et al. 1996a), producing a flying chick in 1994, 1995, 2004 and 2005, and every year between 2003 and 2006 (L.R. Monteiro, V.C. Neves, J. Bried and M.C. Magalhães pers. com..). Other species observed in this IBA: Great Shearwater, Yellow-legged Gull.
BirdLife International (2022) Important Bird Areas factsheet: Santa Maria. Downloaded from http://www.birdlife.org on 10/12/2022.