Leucophaeus atricilla (MGT) Larus atlanticus (MGT) An overview of migratory birds in Brazil 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 Papéis Avulsos de Zoologia 2018 2018-02-20 58 1 66 BSK Rafinesque 1815 [170,259,218,243] Aves Laridae Animalia Charadriiformes 14 15 Chordata family    Leucophaeus atricilla(MGT): breeds in northern USAand southern Canadaand migrates to South America. It overwinters from Mexicoto southern Peruon the Pacific coast and from North Carolina to Brazilon the Atlantic coast ( Burger et al.,2016). In Brazil, it occurs from the mouth of the Amazon River to the bay of São Marcos/ MA ( Antas, 1987) Although its typical distribution on the Brazilian coast is in AP, PA and MA, there are also records for AM, CE, RJ, SP ( Lima et al.,2010) and Trindade Island ( Dias et al.,2010a). In the Amazonian region, records are for AP from August to April and for PA from September to July ( Valente, 2011; Xavier & Boss, 2011; WikiAves, 2016; MPEG). In the Northeast region, it occurs in MA in almost every month of the year ( Rodrigues & Carvalho, 2011b; WikiAves, 2016) and in CE,PI, RN and BA from September to May ( Albano & Girão, 2011; Girão & Albano, 2011a, b; WikiAves, 2016), but there are also records of what probably are juveniles for CE and RN in July (WikiAves, 2016). For RJ and SP, there are few records in January, April and November (WikiAves, 2016) and for RS, the species was recorded in January and July ( Sick, 1997;WikiAves, 2016).   Larus atlanticus(MGT): occurs from southeastern Uruguayto Argentina, where it breeds ( Grantsau, 2010). An estimated number of 150 individuals overwinter annually in RS and they occupy sparsely the oceanic coast and the estuary from Lagoa dos Patos, where at most 50 individuals occur regularly between April and August (FZ- BRS, 2013). Although records are centered in the period between April and August, there are occasional records from September to November, February and March (WikiAves, 2016). The species also occurs in SC ( Burger et al.,2016) in June and August (WikiAves, 2016) and PR in April and June ( Pacheco et al.,2009; WikiAves, 2016).