Stercorariidae, Gray, 1870

Somenzari, Marina, Amaral, Priscilla Prudente do, Cueto, Víctor R., Guaraldo, André de Camargo, Jahn, Alex E., Lima, Diego Mendes, Lima, Pedro Cerqueira, Lugarini, Camile, Machado, Caio Graco, Martinez, Jaime, Nascimento, João Luiz Xavier do, Pacheco, José Fernando, Paludo, Danielle, Prestes, Nêmora Pauletti, Serafini, Patrícia Pereira, Silveira, Luís Fábio, Sousa, Antônio Emanuel Barreto Alves de, Sousa, Nathália Alves de, Souza, Manuella Andrade de, Telino-Júnior, Wallace Rodrigues & Whitney, Bret Myers, 2018, An overview of migratory birds in Brazil, Papéis Avulsos de Zoologia 58, pp. 1-66 : 14

Stercorariidae

Stercorarius skua (MGT) : breeds in northern and eastern Europe and overwinters on the coast of the Iberian Peninsula, Cape Verde, Caribbean and northern Brazil and one small group overwinters in Grand Banks/Newfoundland, Canada. This species departs from its breeding areas in August-September, heading south. It overwinters mainly in open sea and its return migration is between March and April. Immature individuals eventually remain in the south during the breeding season ( Furness, 2016). In RS, there are records of ill or dead individuals in the open sea or occasionally along beaches in April, July and August ( Belton, 1994).There are reports of individuals banded in Europe without confirmed dates that were recovered in MA in February and in CE and PI in March ( Sick, 1997). Museum records are restricted to PA in December and January (MPEG) and to SP in August (MZUSP).

Stercorarius chilensis (MGT) : its movement is little known, but it seems to fly north after breeding on islands and remote coastal areas in Chile and Argentina, reaching southern Peru and possibly to the east as far as west of the Malvinas /Falklands ( Furness, 1996). It is considered a winter visitor in Brazil ( Furness, 1996) and there are few records published for the country ( Olmos et al., 2006), for SC in July, September and November ( Piacentini et al., 2005) and many others without accurate locality for BA, ES, RJ, SP and RS ( Olmos et al., 2006; Grantsau, 2010).The abundance of records in WikiAves, which are centered in the period between June and September, suggests a regular presence of this species in the country, especially in RS and SC; there are also records for PR, SP and ES (WikiAves, 2016).

Stercorarius maccormicki (MGT) : nests in Antarctica, leaves the colonies in March and returns in October-November ( Furness, 1996). In general, it flies towards the North Atlantic through the African coast. Adults seem to remain near the colonies, but there are records of some juveniles performing long migrations ( Olmos et al., 2006). This species occurs in Brazil mainly during the non-breeding season and there are photographic records for MA in December, RN in October, SE in September and May, and for BA from September to November, as well as from April to June (WikiAves, 2016). There are also records for SP in May (MZUSP 102643), August and November, PR in May, SC in July, August and November, and for RS in April (WikiAves, 2016).

Stercorarius antarcticus (MGT) : occurs below the Tropic of Capricorn on southern seas and reaches Tierra del Fuego, the Antarctic Peninsula and New Zealand. The subspecies S. a. antarcticus is more frequent in Brazil; it breeds on the Malvinas /Falklands and in southeastern Argentina and overwinters in the open sea in southeastern South America ( Furness, 1996). Individuals from the subspecies S. a. lonnbergi, which breed on the islands of the Austral Ocean, in the Antarctic Peninsula and islands south of New Zealand, were recovered in RS, SC, PE, AL and CE ( Sick, 1997; Olmos, 2002a). Most populations probably remain near their breeding areas, but especially those located more to the south are considered migratory ( Olmos et al., 2006). Photographic records for Brazil are centered in the winter and they document the species’ presence in BA in May, PR in June and September, SC in August and RS between June and October (WikiAves, 2016) and occasionally on the coast of MA ( Hurtado et al., 2012).

Stercorarius pomarinus (MGT) : nests in the tundra between Greenland, Canada, Alaska, Siberia, northern Russia and extreme northern Scandinavia ( Olmos et al., 2006). After breeding, it begins long transequatorial migrations mainly in September to overwinter in low latitude seas especially in the Northern Hemisphere. It returns in May, usually in smaller flocks ( Furness, 1996). In Brazil, there are records for PA, SP and RS ( Olmos, 2000c) and photographic records for the coast between SE and RS, as well as for PA, MA, PI and RN, which are centered in the period from September to May (WikiAves, 2016).

Stercorarius parasiticus (MGT) : breeds in the Arctic, in the coastal tundra region, primarily between 57°N and 80°N. It overwinters on oceans in the Southern Hemisphere, especially near the coast of South America, southern Africa, southern Australia and New Zealand. It is mostly a transequatorial migrant and few individuals overwinter in the Northern Hemisphere. It departs from the colony in August flying south along the coast.The return journey is quick and happens between April and May ( Furness, 1996). On the Brazilian coast, particularly in RJ, it occurs in larger numbers in January, but there are records from March to May and from September to December.One individual banded as a chick in Finland was recovered in RJ in June and another banded in Scotland was recovered in AL in May ( Sick, 1997). The species occurs regularly on the coast of SC, and although most records and most individuals are from November to April ( Piacentini et al., 2005), there are occasional records throughout the year, which also happens in RS ( Belton, 1994; WikiAves, 2016). For all other states (PA, MA, PI, CE, RB, BA, ES, RJ, SP and PR), records are restricted to the period between September and May (WikiAves, 2016; MZUSP).

Stercorarius longicaudus (MGT) : nests on the central region of Scandinavia, Siberia, Alaska and Greenland, and there are occasional records for Scotland and Spitsbergen ( Olmos et al., 2006). This species is a highly pelagic transequatorial migrant that moves south between August and October and returns to the Northern Hemisphere between April and May ( Furness, 1996). Its flyways and wintering grounds are little known ( Furness et al., 2016), but there are records for Brazil for SE, BA, SP, SC and RS between October and April ( Belton, 1994; WikiAves, 2016).