Accipitridae, Vigors, 1824

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 : 25

Accipitridae

Elanoides forficatus (MPR) : occurs from the southeast coast of the USA to eastern Bolivia, Paraguay and northern Argentina, and two subspecies are recognized: E. f. forficatus and E. f. yetapa, both which occurs in Brazil ( Bierregaard & Kirwan, 2016a). There are records of breeding activity in the Brazilian territory for MT,TO, SP, PR, SC and RS between November and February (WikiAves, 2016).In the Amazon, where it also breeds, only one nest was recorded in the Upper Negro River ( Thiollay, 1994). It is relatively common in most of its distribution and migratory in the extreme north and south of its global occurrence: chicks banded in Florida in June were recovered in PR in December and in MT in October and November ( Sick, 1997). There are also records for RS between September and March ( Belton, 1984). There is no doubt about its migratory behavior, but tracking studies should be performed due to the presence of both subspecies in Brazil sharing geographical areas for at least part of the year (B. Whitney, pers. obs.).

Ictinia plumbea (MPR) : occurs from northeastern Mexico to western Ecuador, Paraguay and northern Argentina and Brazil ( Bierregaard et al., 2016). It is migratory in the north and south of its global distribution ( Jahn & Cueto, 2012), and the limits of its populations are not well known. Groups, probably of nomads, appear sporadically throughout the Amazon ( Bierregaard et al., 2016) and are recorded in the region of Alter do Chão/PA only during the rainy season from February to July ( Sanaiotti & Cintra, 2001). In Brazil, this species occurs sporadically in the Northeast and it breeds in the Amazon and in the Central-West, Southeast and South regions. For PR, SC and RS, records are restricted to the period between August and April (WikiAves, 2016; MNRJ; MZUSP).Therefore, there is a resident and a migratory population in the Brazilian national territory.

Rostrhamus sociabilis (MPR) : occurs from southeastern USA to northeastern Argentina and populations from the south of the global distribution are migratory ( Sick, 1997). This species performs nomadic movements triggered by drought or drainage of its feeding areas ( Bierregaard & Kirwan, 2016b). It departs from the southern region of Brazil in April and returns in September,and some individuals fly to the Pantanal, where they form groups of up to 600 individuals in feeding areas ( Bierregaard & Kirwan, 2016). There is no record of breeding in the Pantanal and large groups (40-80) have been seen departing from the central area and heading south ( Antas, 1994). In the Paraguay River, it is more common in October, when it flies south in flocks ( Thiollay, 1994).There are records of flocks of about 1,000 individuals flying from the north to the south over Sapucaia do Sul/RS in October 1976 ( Sick, 1983). In October 2010, a flock of thousands of individuals (between 2,500 and 3,000) was seen flying from the north to the south in Chapada dos Guimarães/MT (P.P. Amaral, pers. obs.). There are records of breeding activity for CE, Alagoas (AL), Piauí (PI), Espírito Santo (ES), RJ and RS, where the species has been recorded in all months of the year (WikiAves, 2016), as well as in MG and SP (L.F. Silveira, pers. obs.).