Greater Rhea was once common (Marcgrave 1648), but the native population, mentioned from many historical localities, became extinct sometime between 1913 (Alves 1977) and 1959 (Faria 1961). The name R. a. macrorhyncha P. L. Sclater, 1860, from north-east Brazil (Sick 1993, 1997), is not generally accepted by recent works (Piacentini et al. 2015, ICMBio / MMA 2018, Gill & Donsker 2019), but taxonomic and distributional limits of the various subspecies require revision (Piacentini et al. 2015). An unidentified taxon was reintroduced in the 1990s at Seridó Ecological Station (ESEC Seridó) (06°35′S, 37°15′W; 200–385 m), Serra Negra do Norte, where a small feral population persists, and subsequently in several private and protected areas in the state, where some still thrive.

Previously considered probably extinct in the state based on interviews conducted by FSM & DMH with local people in Goianinha, who referred to it as ‘zabelê’, this tinamou has recently been ‘rediscovered'. The first proof of its continued presence was obtained in a forest fragment (05°48′S, 35°21′W) near Natal International Airport, São Gonçalo do Amarante, on 19 December 2018 (WA 3217181; R. Araújo). This locality appears too small and isolated to have conservation potential. Although we follow Piacentini et al. (2015), a recent reassessment recommended that C. n. zabele be treated at species level (Tomotani & Silveira 2016).

A pair introduced in ESEC Seridó, Serra Negra do Norte, was seen breeding in 2002 by FSM, but not in 2012–16 (MP pers. obs.). Previously mentioned for the state (Silveira & Varela-Freire 1999, Azevedo et al. 2004, Silva et al. 2012), but not documented until a group was photographed at Augusto Severo on 4 September 2015 (WA 2168387; C. Brito) and 13 December 2015 (WA 1951196; J. van den Bosch). Partially migratory in Brazil (Antas 1994, Sick 1997), rare or occasional in many places (Sick 1997), but resident in nearby Ceará (Somenzari et al. 2018). Rio Grande do Norte records probably involve southern migrants, but it is also a potential breeder.

Probably two taxa of the P. superciliaris complex occur in RN: the Critically Endangered P. s. alagoensis (ICMBio / MMA 2018) in the Atlantic Forest and restinga (L. F. Silveira pers. comm.; WA 515077; E. Silva), with perhaps the Data Deficient P. s. ochromitra Neumann, 1933 (not Spix, 1825 as in Piacentini et al. 2015), in the interior. The latter is not confirmed, but Penelope flight feathers collected by FSM at Serra das Queimadas, Parelhas, and Serra do Salobro, Luís Gomes, could be identified at MZUSP as only “not P. jacucaca” (L. F. Silveira pers. comm.). A recent review of the complex suggests that these taxa should be treated as full species (Vargas 2017).

Just two photo-documented records of this Vulnerable species: at Tibau on 17 June 2010 (WA 2016795; B. França) and Ruy Barbosa on 5 March 2017 (WA 2491752; A. Barbosa). The status of this Caatinga endemic is very poorly known in Rio Grande do Norte; interviews with local people by FSM suggested some local extinctions, but these do not certainly refer to P. jacucaca, as two species of guans appear to frequent the Caatinga (see above).

Three specimens (MCZ 186306, 186307 and 226729) collected by G. H. Mackay at Cabo São Roque, c.3 km north of the Maxaranguape River mouth (05°29′S, 35°16′W), Maxaranguape, on 9 June 1863 (Carlos et al. 2004) are the only state records.

An adult D. c. capense (MCZ 226730), collected by G. H. Mackay at Cabo São Roque near the mouth of the Maxaranguape River (05°29′S, 35°16′W), Maxaranguape, on the same date as the previous species, another austral migrant (Carlos et al. 2004), is the sole state record.

Two recoveries of birds originally ringed in Macaronesia: a nestling (CEMPA L41317) on Selvagem Grande, Madeira, on 17 September 1991, found by P. H. C. Cordeiro at Pirangi beach, Parnamirim, on 11 July 1994, c.4,490 km from the banding site; and one, banded (Spain 6123288) in the Canary Islands on 2 November 2000, found at Extremoz (05°40′S, 35°W) on 12 January 2001 (Olmos 2002). Two other dead birds, identified using Lima et al. (2004), were found by FSM, of which the mummified remains of one at Canto do Amaro (05°05′S, 36°20′W), Guamaré, on 17 December 2010, will be deposited at COUFRN. Live birds: several photographed off the east coast between 24 November and 22 December 2006 (L. França; confirmed by F. Olmos), one close to the north coast at Guamaré on 6 January 2012 (WA 2518923; MP), another at Galinhos on 31 December 2014 (WA 1569868; F. Torres), and 20 seen 27 km east-northeast off Natal (05°43′S, 34°57′W; depth 200 m) on 24 January 2015 (WA 1593241; N. Moura; Lees et al. 2015). Also sporadically observed flying over the mangroves of the north coast, at Salina Diamante Branco (05°05′S, 36°17′W), Galinhos (Azevedo et al. 2004), and Canto do Amaro on 19 December 2012 (FSM). It appears that C. borealis is regular offshore during the boreal winter, with the immature recovered in July. This is consistent with birds from Macaronesia and Mediterranean wintering in the western Atlantic, where the species has been found year-round (Lima et al. 2004, Somenzari et al. 2018).

One photographed offshore (05°48′S, 34°56′W) on 9 December 2017 (ML 77958651, 77958661; F. Olmos) was the first state record, although this transequatorial migrant was expected given the discovery of one beached on the main island of Fernando de Noronha National Park in 1995 (MZUSP 75463) (Schulz-Neto 2004a, Silva e Silva 2008). Many seen with Manx Shearwaters P. puffinus off Trairi, Ceará, on 14 September 2018 (WA 3111847; C. E. Moura). These three records in extreme north-east Brazil are all beyond the species' regular northern limit off Brazil, the state of Bahia (Somenzari et al. 2018).

Of two beached individuals found by JBI at Senador Georgino Avelino in December 2004, the fresher bird was deposited at COUFRN, as was one found at Via Costeira beach, Natal, donated by the environmental agency IBAMA / Natal prior to 2008; however, both frozen corpses were effectively destroyed by an electricity outage at COUFRN on 1 February 2009. The mummified remains of one found by FSM beached at Chapadão de Pipa, Tibau do Sul, on 31 December 2007, will be deposited at COUFRN. Two undated specimens, donated by Aquário-Natal, lack precise localities: COUFRN 838, and female, COUFRN 949, dated 24 September 2012, although it was probably found earlier than this. Recently photographed at sea off Rio Grande do Norte: adults (WA 2813943; J. Quental, WA 2844237; E. Ramirez) c.20 km off Natal on 10 December 2017, and another on 13 May 2018 (WA 2971931; M. Farah). P. gravis breeds on islands in the South Atlantic in November–April, moves north of the equator between March and September, and visits waters off north-east Brazil in March–December (Lima et al. 2004, Somenzari et al. 2018), which is consistent with the six dated records here.

First known from the discovery of beached individuals: one at Barra do Cunhaú, Tibau do Sul, on 24 December 2002; one at Cotovelo, Parnamirim, on 11 December 2004 (FSM); COUFRN 831, found by R. Gondim at Forte dos Reis Magos, Natal, on 23 September 2005; one at Chapadão de Pipa, Tibau do Sul, on 1 January 2008 (FSM); an undated female at Via Costeira, Natal, donated by IBAMA / Natal in 2008, but effectively destroyed by an electricity outage at COUFRN; and eight along 1.5 km of beach at Búzios, Nísia Floresta, on 29 May 2012 (C. Ferreira, identified by FSM). There is an unpublished recovery of a fully grown individual, ringed (EW 77936) at Mallaig (57°N, 05°49′W) in western Scotland by A. D. K. Ramsay on 20 September 2009, found dying by V. Andrade on Cacimbinha beach, Tibau do Sul, on 15 January 2013, c.7,525 km from the banding site. Hundreds were observed (some photographed) at the shelf break, 27 km east-northeast off Natal, on 25 January 2015 (Lees et al. 2015). One flying south 200 m offshore at Santa Rita, Extremoz, on 1 November 2009 (FSM). This species frequents Brazilian and Argentine coasts during the boreal winter (December–March), and breeds in the north-east Atlantic, with isolated records from July and November in Bahia (Somenzari et al. 2018). Our data show that P. puffinus frequents eastern coastal waters between September and January, with one record in May, thus, is more common off Rio Grande do Norte than previously supposed (Mestre et al. 2010, Somenzari et al. 2018).

A beached female with just one leg (COUFRN 120; Fig. 2) was found by the environmental police at Ponta Negra, Natal, on 3 August 2009. The large black hood and its ragged border, which are the best features to distinguish this species from White-bellied Storm Petrel F. grallaria (Howell 2010), identify the specimen as F. tropica, while the spotted underparts, rather than pure white belly of F. t. melanoleuca, indicates the nominate subspecies (Howell 2010, Robertson et al. 2016). Note that toe projection and the presence of white feathers on the chin and throat are not necessarily useful for species identification, while the black leading edge of the underwing, narrower in F. grallaria (Howell 2010), is not fully visible in our specimen. The only state record, and the fourth specimen of F. tropica for Brazil (Lima et al. 2004). This austral migrant had already been reported from far north-east Brazil (Olmos 2000): during the 19th century c.30 were observed around a ship some 290 km from Fernando de Noronha archipelago (Silva e Silva 2008). F. t. tropica presumably frequents Brazilian waters mainly during the austral winter (Lima et al. 2004, Somenzari et al. 2018); a record from Bahia in January (Olmos 2000), i.e. the austral summer, may have involved an immature.

The first documentation of this austral migrant in state waters was published by Lees et al. (2015) from over the slope (05°43′S, 34°53′W; depth 2,400 m), which is outside the boundary we have defined but very close to the shelf break (05°43′S, 34°57′W; depth 200 m). Another photo also taken on 24 January 2015, is from the same general area, 27 km east-northeast off Natal (WA 1593174; A. Lees). Previously, one was observed <20 km off Natal during a trip to Atol das Rocas in 1994 (A. Schulz-Neto). It is unknown which of the two subspecies occurs: the nominate, which breeds on subantarctic islands, or O. o. exasperatus from Antarctica. Both occur in Brazil (Piacentini et al. 2015), where previously recorded between March and November (Lima et al. 2004, Somenzari et al. 2018); the January records from Rio Grande do Norte extend its temporal presence in the country's waters.

A specimen of this Vulnerable species (COUFRN 728), donated by IBAMA / Natal, was found on the state's north coast, either on a petroleum platform or a beach, and prepared as a specimen on 6 September 2012 by MP. Two were photographed by A. Lees (WA 1593164) and F. Olmos at the shelf break (05°43′S, 34°57′W; depth 200 m) on 24 January 2015 (Lees et al. 2015). Sick (1985) cited a March record for the state, albeit perhaps from Atol das Rocas, which is sometimes considered part of Rio Grande do Norte, but it was not mentioned in Sick (1993, 1997). Part of the Northern Hemisphere population winters off Brazil, with records from Amapá south to São Paulo, mainly in January–February (Somenzari et al. 2018).

The presence of Jabiru in the state was based on an undocumented old record until 2012. Sr. Raimundo, when 73 years old, informed FSM on 11 September 2011 that in the rainy 1960s ‘tuiuiús' (J. mycteria, which he described well) reached Acari, and one was hunted. “We ate it. The flesh is black, as tasty as that of a duck”, he said. The first documented record involved one on an islet in Pau dos Ferros Dam (06°10′S, 38°11′W), Pau dos Ferros, in February 2012 (Fig. 3A), followed by two at Carnaubais (05°12′S, 36°47′W) on 28 February 2018 (Fig. 3B). Around the same time other records were made in Pernambuco (Pereira et al. 2012) and Ceará (WA 3194160) confirming the species’ occasional occurrence in the Caatinga, during wet periods.

Three in a mixed colony of several species of white herons at Umari, Caicó in the Caatinga, in 1998 (C. Medeiros) represented the first state record. An adult with heavily worn and disorganised wing feathers and a dirty body was photographed flying over Messias Targino on 13 December 2015 (WA 1945521; J. van den Bosch).

There is an unpublished recovery of this frigatebird banded as a nestling (CEMAVE U07889) on Fernando de Noronha (03°52′S, 32°26′W) on 25 June 1987 by A. Filippini, and recovered at Pitangui beach (05°30′S, 35°10′W), Extremoz, sometime prior to 1997 (SNA 2019; A. Schulz-Neto pers. comm.). Regular visitor to the state's coasts, being well known to fishermen as ‘garapira'. Its seasonal distribution, based on 52 records (some documented), shows individuals (including adult males) and groups of up to nine occur year-round. At Baía Formosa, flocks of 16 and 15 were seen by FSM interacting with fishing Guiana Dolphins Sotalia guianensis in December 2002 and January 2003, respectively.

An adult male found alive on Santa Rita beach, Extremoz, on 8 October 2008, was taken to Natal Zoo (Fig. 4), where it subsequently died. It was only recently prepared as a specimen (COUFRN 1253). The first available documented records were off Natal at the shelf break (05°43′S, 34°57′W; depth 200 m) (Lees et al. 2015). There are three unpublished recoveries in the state: a nestling, ringed (CEMAVE U23323) on 19 July 1994 on Santa Bárbara Island, Abrolhos National Park (17°58′S, 38°42′W), Caravelas, Bahia, caught at sea (05°06′S, 36°38′W) north of Macau in 1997; an adult, ringed on the right leg, said to be from Abrolhos, Bahia, landed on a floating platform at the Maracajaú Reef (05°40′S, 35°24′W; depth 5 m), 7 km off Maxaranguape, where it was fed, in 2000 and 2002 (Risonaldo pers. comm.; photo identified by FSM); and an adult with a ring on its right leg, photographed on Búzios beach, Nísia Floresta—not in Natal as indicated—(see WA 549593) and subsequently released by the environmental police (G. Rodrigues pers. comm.). S. dactylatra appears to be the commonest of the three Sula species that occur in the state's waters.

An adult in typical plumage was found on the coast in 2018 and was prepared as a specimen (COUFRN 1275) on 28 September 2018. This is the only state record.

One struck the window of JBI's house close to the floodplain of the Pirangi River, Parnamirim, on 28 May 2008. Its frozen corpse was effectively destroyed by an electricity outage at COUFRN. This was the only state record for some years, but live individuals were subsequently photographed (see WikiAves 2019).

One observed at Povoado de Sítio in Ceará-Mirim between February 2001 and June 2002 (M. Silva) was the first state record. A female at the lagoon in Martins on 6 August 2010 was the second (FSM). The first documented record involved an adult male at the main pond in ESEC Seridó, Serra Negra do Norte, in 2012, photographed by C. A. Varela-Freire ( www.carlosvarela-agenteambiental.blogspot.com). Finally, an adult female was at Mossoró on 25 December 2016 (WA 2411673; RDL). The species' status in the state is unclear, but the record in December suggests possible local breeding.

The only state record is a photo of an adult flushed from cattails in the mobile sand dunes at Guamaré on 18 May 2012 (WA 3065361; C. Ferreira, identified by FSM).

The only documented state record involves a skull (SDNHM 35485) collected by F. Baker at ‘Paparý Lake’ (06°07′S, 35°10′W), Nísia Floresta (Fig. 5). Although the date of the specimen is not given, it can be attributed to 1911, corresponding to the date of a mollusc-collecting expedition during which it was discovered (Baker 1913). Interviews with local people convinced FSM as to the presence of this species in mangroves at Macau and Guamaré until the 1960s, but suggest that it is now extinct; however, one, probably of this species, was observed flying over Macau around December 2009 (JBI). The nearest recent documented records to Rio Grande do Norte are from north-west Ceará and Alagoas, meaning the species could wander to the state.

Widely reported in the state: Macau (Andrade 1991, Sick 1997); Seridó (Varela-Freire & Araújo 1997); the littoral around Potiguar petroleum basin: Macau, Assu, Galinhos, Guamaré, Porto do Mangue (Varela et al. 1997, Azevedo et al. 2004, Irusta & Sagot-Martin 2011, Silva et al. 2012); and Grossos (Girão & Albano 2011). However, there was no documented record for the state until an adult was photographed in flight at Galinhos on 21 November 2009 (WA 252946; B. França). Another record for the southern interior was at ESEC Seridó, Serra Negra do Norte (Pichorim et al. 2016b). A female P. h. carolinensis named ‘Holly' banded (1088-07037) and tagged (388) as a young adult, along with its mate, in Annapolis (38°60′N, 76°29′W), Maryland, USA, was also fitted with a datalogger (Fig. 6A), which revealed that the bird twice migrated to Rio Grande do Norte, covering c.8,000 km on each journey. ‘Holly' remained in the Piranhas basin (05°44′S, 36°53′W) between 16 October 2016 and 15 March 2017 and from 9 November 2017 to 14 March 2018 (Fig. 6B). On the next migration, ‘Holly’ wintered in the state of Ceará, in the Acaraú basin (04°14′S, 40°27′W) (R. Bierregaard pers. comm.). North American Ospreys had previously been recovered in the neighbouring states of Paraíba, initially on 4 February 1973, and Ceará, on 10 February 1983 (Mestre & Bierregaard 2009), but not in Rio Grande do Norte (Mestre et al. 2010).

A presumed adult was flushed from the ground on the left bank of Jiqui River, then circled overhead with a Black Vulture Coragyps atratus before disappearing behind forest at Parnamirim, on 15 January 2007 (FSM). This first state record of an Endangered northeast Brazilian endemic was originally considered doubtful due to possible confusion with White-necked Hawk Amadonastur lacernulatus, which is now known to occur only south of the São Francisco River (Dénes et al. 2011). FSM subsequently observed an adult and young L. forbesi at the same locality, on 20 July (with JBI) and 22 July 2009, respectively. Proof of occurrence was obtained by a high-flying bird photographed at Baía Formosa on 4 September 2016 (WA 2263455; D. Gurgel).

The first documented state record involved an adult banded (CEMAVE H110936) at the Universidade Federal Rural do Semi-Árido farm (05°03′S, 37°24′W), Mossoró, on 26 April 2014 (L. França & P. T. Moura; Fig. 7A). Another Caatinga record was of one captured by MP at ESEC Seridó, Serra Negra do Norte, on 12 June 2014 (Fig. 7B). The subspecies involved is A. s. erythronemius, with a finely barred white chest, rufous-grey belly and red flanks and thighs (Ferguson-Lees & Christie 2001), which is sometimes treated as a species (Gill & Donsker 2019).

The first state record was of four flying south-east over Serra do Feiticeiro, Lajes, on 6 March 2006 (FSM), while one perched beside the road to Jardim do Seridó (06°39′S, 36°42′W), Parelhas, on 10 April 2006 (photographed by L. Sena) may pertain to the same migratory movement. Further records suggest overwintering adults from a southern population: singles at the Jiqui and Pitimbu floodplain, Parnamirim and Nísia Floresta, on 20 July 2009, and in the same area (WA 249719; B. França) on 5 August 2009 (FSM & JBI), with two there on 11 July 2016 (FSM). More surprisingly, two recent records of juveniles: one over São Miguel do Gostoso on 27 May 2018 (WA 3010251; T. Almeida) and one over Currais Novos on 17 February 2019 (WA 3282753; G. Medeiros), the latter date suggestive of local breeding. In Brazil, there are resident and migratory populations of I. plumbea, which depart the south of the country mainly in May–July, and occur sporadically in the north-east, where it is not known to breed (Somenzari et al. 2018).

In 2002, FSM became convinced that a population exists in the mangroves of Canguaretama, based on interviews with local people during a canoe trip on the Camamirim River. They spoke of the ‘gavião-piri-piri’ or ‘pixi-pixi'—onomatopoeic names for B. aequinoctialis—and pointed out a place where one had a nest. A calling bird was heard on the Camamirim River on 27 December 2002 and two were observed flying over the Penha River on 6 January 2003; an adult was seen in the same mangroves on 22 April 2005 (FSM). Ten years later, on the south side of this mangrove complex, at Baía Formosa, sightings were made in August and October 2015 (FSM), and it was finally documented by photos and video on the Garatuba River (06°23′S, 35°04′W) on 25 October 2015 (WA 2874182; DMH). It is estimated that the Rio Grande do Norte population of this Near Threatened species is just 5–10 pairs, with no records elsewhere in the state. In extreme north-east Brazil, it appears to have disappeared from Ceará (WikiAves 2019), where it was formerly present (Pinto & Camargo 1961). More recently, it was found in mangroves of the Mamanguape and Paraíba do Norte Rivers (Araujo et al. 2006), and elsewhere in nearby Paraíba (WikiAves 2019). Although recent records in mangroves in the Atlantic Forest domain are restricted to a few localities (Moreira-Lima 2013), we believe the species is recovering in parts of north-east Brazil, possibly due to the less systematic destruction of raptors than in previous decades.

An adult in wing moult was caught alive by a poacher's hunting dog at Maiada do Fogo, in the floodplain of the Ceará-Mirim River, Ceará-Mirim, on 23 October 2005, and was given to M. Silva. Photos were taken next day by JBI (Fig. 8) before it was released at the same location. On 8 July 2007, FSM & M. Silva flushed one that briefly perched at Sítio (c.05°36′S, 35°30′W), Ceará-Mirim, in the same floodplain. One was photographed by D. Gurgel and P. Vitor in the same municipality on 23 October 2016 (WA 2336075, 2334287, 2333420). The status in Rio Grande do Norte of this Data Deficient crake (ICMBio / MMA 2018) remains to be clarified.

Few reports from north-east Brazil, where this crake is a seasonal visitor and a probable breeder during the rainy season (R. Otoch pers. comm.). In the state, adults have been found dead or moribund three times: a full-plumaged decaying corpse, which had been struck by a vehicle on the road to Cacimbinha, Tibau do Sul, in the Atlantic Forest, found by V. Andrade on 2 May 2006, photographed by DMH and deposited in alcohol at COUFRN by FSM; one with a wound to its right eye, captured by hand and photographed immediately after release at Cajueiro stream, which divides the municipalities of Parelhas and Equador, in the Caatinga, on 5 June 2008 (WA 343447; L. Sena); and a female found dead in the early morning by M. Viana & Z. Coringa, either having struck a wall or a vehicle, at Pium (05°57′S, 35°10′W), Parnamirim, in the coastal Atlantic Forest on 23 March 2015 (COUFRN 1224) (Fig. 9). In Parelhas, an adult foraging on wet ground was photographed on 10 May 2018 (WA 2969079; L. Sena), and the tiuk call was sound-recorded during the same good rainy season on 2 June 2018 (WA 2992265; J. Dantas).

The South American resident population breeds on northern and eastern coasts of Rio Grande do Norte (Sick 1997; FSM & JBI pers. obs.); the presence of migrants from North America is yet to be proven. A specimen taken in Canguaretama sometime between September 1997 and November 1998 and deposited at UFPE (Nascimento & Larrazábal 2000) can no longer be found there (L. Naka pers. comm.). Additional studies are needed to define geographic boundaries and diagnosis of C. w. crassirostris and C. w. cinnamominus.

Three ringed as juveniles in North America were recaptured and released in the state: BBL (Bird Banding Laboratory, USA and Canada) 1151-15400, New Brunswick, Canada (45°43′N, 64°31′W), on 25 August 1988, recaptured at Canguaretama (06°20′S, 35°01′W) on 25 March 1995; BBL 1431-68689, New Brunswick, on 10 August 1999, recaptured at Galinhos (05°06′S, 36°10′W) on 24 October 2000; and BBL 1541-46316, New Jersey, USA (39°10′N, 74°51′W), ringed on 23 May 2000, recaptured at Galinhos on 13 November 2000 (Mestre et al. 2010; L. Mestre pers. comm.). Birds migrating through south-east Canada belong to the nominate form.

There has been one alleged recovery of a ringed Willet in the state (Lara-Resende & Leal 1982), questionable because it was mapped outside its coastal range. Forty photos taken on both the north and east coasts (WikiAves 2019) are mainly the nominate, but it is difficult to eliminate Western Willet T. s. inornata in some cases (O'Brien et al. 2006). Our voucher, an individual with an evenly heavy bill to its tip and contrastingly darker scapulars and paler coverts, photographed at Galinhos on 15 November 2014 (WA 1522100; J. van den Bosch), is of the eastern nominate. Some authors consider the races as separate species that can be syntopic on migration and in winter (Oswald et al. 2016).

One, ringed in New Jersey, USA, in 2002—thus presumably A. i. morinella—was seen in Natal on 15 March and 6 May 2005 (FSM). Individuals were also re-trapped by S. Azevedo in Galinhos during 22 April–3 May 2003 (Araújo et al. 2004).

Three Red Knots originally ringed in New Jersey, USA (one in 2000 or 2002, and two in 2004; W. Pitts pers. comm.)—presumed to be C. c. rufa—were seen at the Casqueira River, Macau, on 10 January and 17 February 2005, respectively (JBI).

There have been six sightings of four individuals, all marked in New Jersey, USA (thus presumably C. a. rubida), at Forte dos Reis Magos, Natal: one ringed in 2004, observed on 4, 20 and 23 November 2004 (FSM); one ringed in 2003, another in 2004, both seen on 15 December 2004 (JBI); and flag KMJ (banded FWS 1621-19137) attached at Reeds Beach on 14 May 2005, photographed on 30 September 2006 (MP).

The only record is of four observed by JBI in a monitored landfill (05°43′S, 35°23′W) at Ceará-Mirim on 27 September 2012 (ML 27817531).

As distinguishing this species from some congenerics can be difficult, the origin of marked individuals can be useful to guarantee identification: one, ringed prior to fledging at Palmer Station, Cormorant Islands, on 23 February 1980, was recaptured on the state's north coast on 30 October 1980 and released (Lara-Resende & Leal 1982), captured again on 26 April 1984 at the same locality and kept captive; and a nestling, ringed at Admiralty Bay, King George Island (62°S, 58°20′W) on 19 January 1986, recovered at Galinhos on 20 October 1994 (Olmos 2002). One undated specimen (COUFRN 182), donated by IBAMA / Natal, is from Rio Grande do Norte; a dark-morph immature in primary moult was caught at sea and kept captive in Macau, photographed in a cage on 12 September 2008 (JBI, identified by FSM); and one was photographed close to the coast of Natal on 28 October 2012 (WA 791473; V. Florencio). Three of these records are from the same offshore area. Although already proven to occur in the state's waters (Lara-Resende & Leal 1982, Olmos 2002), this skua was mentioned only as a potential species off extreme north-east Brazil (Lees et al. 2015). As with most jaegers, it is a transequatorial migrant that is expected to be fairly common in offshore waters (F. Olmos pers. comm.).

The first photographic record involved one around a boat, pursuing Sula dactylatra and Puffinus puffinus, 27 km east-northeast off Natal at the shelf break, where there were hundreds of terns of four species, on 25 January 2015 (Lees et al. 2015; WA 1593176; A. Lees). Two previous sight records by FSM: one moving south off Cotovelo beach, Parnamirim, on 15 November 2002, and another at Maracajaú Reef (05°40′S, 35°24′W), Maxaranguape, on 30 May 2005.

The first documented record involved a full-plumaged dark-morph adult photographed c.20 km off Natal on 10 December 2017 (ML 77958391; F. Olmos). Previously, individuals had been seen by FSM at Maracajaú Reef (05°40′S, 35°24′W), Maxaranguape: one during 29–31 May 2005, one on 29–30 August 2005, a total of six moving south on 20–21 September 2006, and a total of five moving south on 18–19 October 2006, i.e. during both the boreal spring and autumn migrations.

Hundreds of pairs of this colonial breeder occur in mixed colonies with Gull-billed Terns Gelochelidon nilotica, Cabot's Terns Thalasseus acuflavidus eurygnathus and Black-necked Stilts Himantopus mexicanus in or close to saltpans on the north coast (Azevedo et al. 2004; FSM, JBI & MP). It is recorded year-round, with fewest in December (five birds) and March (12) and largest numbers during the breeding period (April–August), with max. 1,647 nests (eggs, nestlings and a few flying juveniles) at Furado do Avelino, Macau, on 18–19 July 2009 (FSM, MP, B. França & C. Ferreira). Post-nuptial moult of adults noted August–February (FSM), and post-breeding dispersal at Galinhos, in 2012, between 25 September and 30 October (FSM & C. Ferreira). Uncommon on the state's east coast, where we are aware of just three records: at Nísia Floresta in August 2001 (JBI); at the Potengi estuary, Natal between August 2007 and March 2008 (B. França); and two adults photographed at Natal on 6 November 2013 (WA 1151661; R. Oliveira). There is an inland record of two non-breeding adults at Lagoa do Piató, 57 km from the coast, in Assu, on 9 December 2008 (FSM).

An immature with moulting primaries photographed at Guamaré on the state's north coast on 16 May 2010 (WA 287755; B. França) was the first available documented record. Previously observed by FSM, but on the east coast at Maracajaú Reef (05°40′S, 35°24′W), Maxaranguape, where two first-years were present 12 November–6 December 2006 (Fig. 10). On the north coast, 12 (all non-adult) were at the Conchas estuary, Porto do Mangue, on 14 February 2009 (FSM & MP). Most records are from Guamaré: an adult with three first-years at Canto do Amaro (05°05′S, 36°20′W) on 9 November 2010; a first-year at the same location on 19 December 2010; a first-year between Canto do Amaro and Coroa do Moacir on 29 May 2011, and perhaps the same bird at the confluence of the Aratuá and Miassaba Rivers (05°06′S, 36°19′W) on 6 June 2011 (FSM); five (including a breeding-plumaged adult) on Canto do Amaro beach on 28 February 2015 (photographed by C. Ferreira, identified by FSM). Also on the north coast, a first-winter at Areia Branca on 20 January 2012 (WA 574897; C. Beier). It appears that this migrant regularly overwinters (November–February) on the state's coasts, where immatures are present as late as May or June.

The alleged identification of Yellow-billed Tern S. superciliaris at Salina Diamante Branco (05°05′S, 36°17′W), Galinhos, was accompanied by the following comment: ‘arrived March–April to breed in colony June–July 1999 and June 2000, one breeding adult collected 18 June 2000’ (translated from Azevedo et al. 2004), and the same species was also reported by Araújo et al. (2004), but the specimen mentioned (UFPE 3139, in fact labelled 19 June 2000) is an adult S. antillarum (Fig. 11). Least Tern is a regular seasonal breeder on sand banks in some mangrove complexes on the state's north coast, as documented at Macau (courtship 29–30 April, one egg on 15 May 2005, and estimated seven pairs around Salina Soledade; FSM & JBI), Guamaré (80 individuals and 20 nests at Rolo da Costa on 29 May 2011; FSM & R. Dantas) and Galinhos (Azevedo et al. 2004). This species frequents coastal waters in dozens or hundreds year-round—except August, when only three recorded. Largest concentrations in January—hundreds at the shelf break off Natal (Lees et al. 2015)—and in April and October, with respective max. of 370 and 325 roosting on floating structures at Maracajaú Reef (05°40′S, 35°24′W), Maxaranguape (FSM). The presence of individuals from the Northern Hemisphere in these flocks is probable, but not documented. North American migrants could occur simultaneously with local breeders, at least in April.

Well-documented records in the state are few. We consider that the following photo-documented records pertain to this species: two breeding-plumaged adults in Natal on 16 May 2011 (WA 611256; D. Barrufi); 16 adults (in various plumages) at Macau on 21 June 2012 (WA 672567, 673494, 675557; J. van den Bosch); an immature, with a brown-margined strong bill and black wing feathers until the sixth primary, at Guamaré on 9 April 2016 (WA 2084773; J. Dantas); a subadult, with a dirty yellow bill and black until the fifth primary, at the same locality on 30 April 2016 (WA 2103818; L. Sena); a breeding-plumaged adult, with a strong bill and three black outermost primaries in Macau on the same date (WA 2104993; J. Dantas); an immature with a streaked crown, dark-tipped strong bill and black until the fifth primary, in Macau on 24 August 2016 (WA 2249902; J. Dantas); and 33, 20 with all-yellow bills, at Areia Branca on 27 February 2017 (WA 2480542; J. C. Rodrigues). Based on this, we assume that adult Yellow-billed Terns visit the state in February–June, with one record of an immature in August.

The north coast seasonally harbours a few colonies comprising dozens of breeding pairs, mixed with breeding Grey-hooded Gulls, in or close to saltpans (FSM, JBI & MP). First proven breeding in June–July 1999 at Salina Diamante Branco, Galinhos, where common in March–August 2000 and a breeding adult was trapped on 17 April 2000 (Azevedo et al. 2004). Also, 50 in June, 23 in July, three in August, and post-breeding dispersal from this colony between 6 July and 13 August 2012 (FSM & C. Ferreira). Fifty nests found by FSM and JBI at Salina Soledade, Macau, on 14 May 2005, where birds absent December 2004–January 2005, returned in February, max. 224 (including four adults on nests) on 8 April, 41 nests with eggs, nestlings and a fledged juvenile on 10 June (with I. Cortez), and adults carrying food on 20–23 June and 1–3 July. At the same colony, in 2006, display in April, nests in May–July, and juveniles in June–August (JBI). On 21–22 July 2007, 22 and 15 first-years at Soledade, Macau, and Lagoa Lagamar, Carnaubais, respectively (FSM & JBI).

Dozens of recoveries from the state's coast have been published, but all lack detailed supporting data (Lara-Resende & Leal 1982, Cordeiro et al. 1996, Mestre 2007b, Mestre et al. 2010). In an unpublished study conducted in 2005–07 by FSM, 16 Common Terns, ringed as non-volant young in New Hampshire, Massachusetts, Connecticut, New York (USA), and the US Virgin Islands (thus assigned to the nominate form) were seen at Maracajaú Reef (05°40′S, 35°24′W), Maxaranguape.

Three coastal recoveries have been published, but all lack detailed data (Lara-Resende & Leal 1982, Mestre et al. 2010). In an unpublished study conducted in 2005–07 by FSM, 14 Roseate Terns, ringed as non-volant young in Massachusetts and New York (USA), a nestling ringed BBL in the US Virgin Islands, and another in the Azores (all assigned to the nominate) were seen at Maracajaú Reef (05°40′S, 35°24′W), Maxaranguape.

Yellow-billed T. a. eurygnathus is a seasonal breeder on the north coast, in a mixed colony with Grey-hooded Gull, Gelochelidon and Himantopus. First proven breeding on 19 July 2009 at Furado do Avelino (Salinor), Macau, with a juvenile and five non-volant young (FSM, MP & C. Ferreira; WA 236785; B. França). Around Salina Soledade and Ponta do Tubarão, Macau, birds were absent in December 2004–February 2005, arrived in March, max. 56 and 78 on 20–23 May and 2 July, respectively (FSM & JBI), and display was observed in March 2006 (JBI). On the same coast, 162 (mainly adults) were at the Conchas estuary, Porto do Mangue, on 14 February 2009 (FSM & MP). In addition, one ringed in Mississippi in December 1964, thus probably of the nominate (Burger 2018), was recovered on the state's north coast in either August 1966 (Sick 1997: 337) or May 1966 (Olmos 2002).

The Caatinga population is Z. a. noronha (Azevedo & Antas 1990). It is a nomadic mass-breeder tracking the production of seeds following the rainy season, and breeds on the ground in large colonies, where thousands are illegally hunted (J. B. de Medeiros pers. comm.) and sold (FSM pers. obs.). Three banded in Piauí and Pernambuco were recovered in Rio Grande do Norte: one, a youngster, banded (CEMAVE L16622) in Itainópolis, Piauí, on 30 March 1984, was recovered at São José do Seridó in July 1985 (Azevedo & Antas 1990).

Known in the state since at least the 19th century, and its onomatopoeic local name, ‘jucurutu’, is replicated in a municipality in Rio Grande do Norte (Cascudo 1968). Rare in the Brazilian north-east, with state records—based mainly on interviews with local people—concentrated in the south and south-west (Lima et al. 2018). It is included in the ESEC Seridó bird list, Serra Negra do Norte (Pichorim et al. 2016b), based on an undocumented record of one that flew low above FSM in a steppe-type landscape (06°35′S, 37°15′W) at dusk on 3 December 2002. Birds in the Caatinga have been considered to represent a separate subspecies (Bubo v. deserti Reiser, 1905), whose validity is questionable (Traylor 1958, Lima et al. 2018).

The only state record was at Santa Izabel Farm (05°07′S, 36°10′W), Galinhos, on 14 August 2012, where one was flushed from bare sand dunes and was mobbed by up to seven Southern Lapwings Vanellus chilensis (Fig. 12; WA 3065349; C. Ferreira & FSM). Except for a handful of localities in Bahia and Piauí states, it seems there are no other records in the Brazilian north-east (König et al. 2009, Olsen et al. 2019, WikiAves 2019), thus that in Rio Grande do Norte represents a range extension of c.1,000 km north-east.

Just one state record, an immature perched on a high horizontal branch of a Tabebuia aurea (Bignoniaceae), in Cerro Corá on 9 July 2017 by D. Oliveira et al. (WA 2615000; J. Dantas).

One documented state record of this rupiculous nightjar: a male at Cânion dos Apertados (06°20′S, 36°30′W), Currais Novos, photographed (WA 3219414) and sound-recorded (WA 3220109) on 21 December 2018 (E. Oliveira).

Seldom recorded in extreme north-east Brazil. A female (COUFRN 1228) found dead at Natal International Airport, São Gonçalo do Amarante, on 26 July 2016, was the first documented state record. One responded to playback at ESEC Seridó, Serra Negra do Norte, on 23 January 2013 and another was heard there on 25 May 2013 (MP), but neither record was documented. A group of 20 settled on a grassy area at Touros on 22 May 2018 (M. Silva; WA 2985934). A partial migrant in Brazil: the nominate subspecies breeds in far southern latitudes and migrates north in the austral winter, when it mixes with resident P. n. minor, which is not known to breed in north-east Brazil (Somenzari et al. 2018). Both documented state records were during the austral winter, and, together with the first published record for neighbouring Paraíba—a flock of 15 photographed on 23 June 2010 (Pereira et al. 2012)—induce us to believe that these were the nominate form. Should Podager (unexpectedly) be proven to occur during the local summer (and rainy season in the Caatinga), this would suggest that P. n. minor breeds in north-east Brazil.

Of the two species of Chordeiles of problematic identification likely to occur, only C. acutipennis has been claimed: recorded but not described in São José do Seridó in July–December 1996 (Medeiros et al. 2000), which justified the species' inclusion in a list of birds of the Seridó region (Varela-Freire & Araújo 1997); one trapped but not described at ESEC Seridó, Serra Negra do Norte (Nascimento 2000, Pacheco 2004); seen but again not described at the same location (MMA 2004); recorded at ESEC Seridó and in Macau based on a reference in Silva et al. (2012), the latter corresponding to repeated observations in March–July 2005 (FSM & JBI), including a photo (WA 3089210; JBI) of an adult male in flight within a loose group of 27 birds, on 21 June 2005; and ringed but not described, and mentioned as occasional at ESEC Seridó during field work on 14 July 2012, 26 January 2013 and 1 June 2013 (C. C. O. Silva et al. 2017). Also at ESEC Seridó, two alleged C. acutipennis were captured on 21 February 2013, both with total length of 20 cm, and mass 33.3 g and 31.9 g, and two others on 9 and 12 June 2013, mass 35.0 g and 34.9 g, respectively (Hasui et al. 2018), but without documentation (MP pers. obs.). These weights might apply to Least Nighthawk Nannochordeiles pusillus (FSM pers. obs.). A photo taken in the Caatinga at Parelhas on 12 March 2006 is not identifiable to species (WA 344901). For now, we recognise C. acutipennis as occurring in Rio Grande do Norte based solely on WA 3089210, whereas C. minor is relegated to our secondary list.

The only holotype of an avian taxon collected in Rio Grande do Norte is the male specimen MNRJ 36897 from Bico da Arara (06°31′S, 36°38′W; 600 m), Acari, of S. b. seridoensis. Two Biscutate Swifts, ringed there during 26–27 August 1986, were recaptured on 4–5 August 1987 (Sick et al. 1988). The population of this non-breeding colony, first studied by Sick and others, appears to be stable or slightly diminishing, at c.90,000–110,000 birds over the last three decades (Andrade & Freitas 1987, Sick et al. 1988, Sick 1991; unpubl. work by FSM in 2005, 2007, 2009, 2011, 2016 and 2018).

Status uncertain, despite repeated records. One at a ‘tabuleiro’ / floodplain ecotone at Sagi, Baía Formosa, on 3 January 2003. A male and female fed at Hohenbergia (Bromeliaceae) in restinga at Morro Vermelho, Nísia Floresta, on 16 November 2004, and a breeding-plumaged male was between Lago Azul and Morro Vermelho on 17 April 2005. In the same municipality, an adult male fed on ornamental orange and red Asteraceae flowers at Pium on 7 January 2006 (FSM). Single males were observed in cerrado at Punaú (05°23′S, 35°30′W), Rio do Fogo, on 21 October and 12 November 2006, and 17 January 2007, during a study between October 2006 and November 2013 (Pichorim et al. 2014a). Moreover, three birds were seen, of which a female was photographed, at Espírito Santo on 3 September 2017 (WA 2682924; J. Dantas) in a ‘tabuleiro’, which had burned the year before. At the same place, there are several documented records, including breeding-plumaged males and a female, in May, July and September–October. To date, Heliactin has not been reported during the period 18 January–16 April, and breeding in the state, although probable, is unproven.

Since 2002, there have been repeated records at Mata da Estrela Private Reserve (06°23′S, 35°01′W), Baía Formosa (FSM & JFP). Of these, the first to be documented was a singing adult on 28 March 2017 (WA 2510629; P. Fernandes). The Endangered subspecies M. m. marcgravianus, endemic to the Pernambuco Centre of Endemism, is not accepted by some authorities, but included by others (Piacentini et al. 2015, ICMBio / MMA 2018, Snow & Kirwan 2019).

Observed in shrubby restinga at Barra do Cunhaú (06°18′S, 35°02′W), Tibau do Sul, on 25 December 2002; carrying avian prey at a forest border at Baía Formosa on 28 December 2002; flying over mangroves at Canguaretama on 5 January 2003; and heard at Serra das Queimadas, Parelhas, on 11 June 2006 (FSM). One was sound-recorded at Mata da Estrela Private Reserve (06°22′S, 35°00′W; 25 m), Baía Formosa, on 30 August 2008 (M. Silva), and the first publicly available documentation is a sound-recording from the same locality on 9 September 2018 (WA 3390273; J. A. Marins).

Both subspecies that occur in Brazil have been recovered in the state (Silva e Silva 1996, Mestre 2007a): a young F. p. tundrius (BBL 987-39774) banded in Alaska, USA (65°N, 141°03′W) on 12 July 1980 and shot in Assu on 15 February 1982, c.12,370 km distant; and a female nestling F. p. anatum (BBL 987-15200) banded in Virginia, USA (37°83′N, 75°17′W) on 9 October 1979 and shot in Natal on 18 March 1981, 6,365 km from its nest.

Discovered in the south-east of the state: a group of eight at an Atlantic Forest / cerrado-like ecotone, in Mata do Pilão, Espírito Santo, on 27 May 2018 (J. Dantas), with a sound-recording from the same location on 10 June 2018 (WA 3233566; M. Silva). A pair was photographed in Natal on 24 May 2011 (WA 359163; S. Messias), but we consider these birds to be of cagebird origin.

A genetic study is needed to clarify the origin(s) of the small populations of this species in the state. As suggested by the collecting of five at Mamanguape, Paraíba, in 1957 (Pinto & Camargo 1961), it has probably been present, perhaps continuously, in Rio Grande do Norte for some decades, possibly originating from and maintained by released or escaped cagebirds, in places such as Natal. The Tibau do Sul breeding population could be feral (DMH). E. aurea is scarce in cerrado at Rio do Fogo (05°23′S, 35°30′W) (Pichorim et al. 2014a), arguably the best habitat for the species in the state.

The subspecies in the state is M. a. luctuosa, which is sometimes treated at species level (del Hoyo et al. 2019b). All records are from Baía Formosa, at Mata da Estrela Private Reserve (06°23′S, 35°01′W), where at least 32 individuals were found during 27 December 2010–3 January 2011 (JFP), and Mata da Pituba (06°27′S, 35°03′W) (RDL).

The population in the Pernambuco Centre of Endemism is generally attributed to H. r. scapularis (Pinto 1978, del Hoyo et al. 2019a), but a taxonomic review of this complex suggests that this population may be a novel taxon, whose plumage and voice is very similar to Amazonian H. r. frater (Silva 2013; JFP pers. obs.).

The only state record was a pair seen and sound-recorded in the valley of the Pituba River, Baía Formosa, on 8 September 2009 (WA 2660533; MP, M. Silva & JBI). The Vulnerable subspecies C. l. sabinoi (MMA 2003) is not always accepted as valid (Bierregaard et al. 1997, Cavarzere 2014) and has not been evaluated by ICMBio / MMA (2018).

The Vulnerable subspecies C. m. nigrifrons is endemic to the Pernambuco Centre of Endemism (ICMBio / MMA 2018). It occurs around Baía Formosa at two localities: first documented at Mata da Estrela Private Reserve (06°23′S, 35°01′W) via a sound-recording on 14 August 2016 (WA 2235397; J. Dantas); and sight records at Mata da Pituba (JBI).

The subspecies in Rio Grande do Norte is X. m. alagoanus, which is considered Vulnerable (ICMBio / MMA 2018) and whose voice is more similar to Amazonian X. m. genibarbis than to the nominate Atlantic Forest population (RDL pers. obs.). Recent molecular data showed that one collected in Pernambuco (FMNH 399212; Field Museum of Natural History, Chicago) grouped phylogenetically with birds in eastern Amazonia, and not with the Atlantic Forest clade (Burney 2009), but this author inferred that the species is paraphyletic, when in fact alagoanus could be ranked as a species. Widely overlooked since its description (del Hoyo et al. 2019c), alagoanus was omitted from a recent phylogeny of the species (Harvey & Brumfield 2015).

Reported to be expanding its range in south-east Brazil (Willis & Oniki 1993; JFP pers. obs.), this thornbird has recently reached western Rio Grande do Norte, where it was found at Serra do Mel in 2007 (G. Pereira), and Umarizal and Luís Gomes, respectively, in May and June 2010 (FSM), and the south-east, at Santo Antônio and Nova Cruz in January 2011 (JFP). It was first documented by a photo of two birds at Passa e Fica on 27 September 2015 (WA 1851438; D. Gurgel).

A Brazilian endemic treated either as Data Deficient (ICMBio / MMA 2018) or Near Threatened (IUCN 2019). The first state record was one trapped at ESEC Seridó, Serra Negra do Norte, on 17 December 1995 (Nascimento 2000). A vocalising pair sound-recorded at 650 m in the Serra das Queimadas, Parelhas, on 14 November 2005 (FSM) is the second. The state's main population is in the highest parts of the Serra de Santana (FSM pers. obs.; Pichorim et al. 2016a). Other records are concentrated in the Seridó region, with a few on the north coast. Very local in distribution, S. hellmayri is probably better considered Near Threatened at state level.

Was considered extinct in the state (Paiva 1983 apud Sick 1972, Teixeira 1992). Rediscovered at Baía Formosa on 13 June 2015 by P. Vitor, F. V. Souza, and J. Dantas, who photographed a female feeding on Psidium fruits (Myrtaceae) (WA 1724942), which is the only documented record.

First record at Mata da Estrela Private Reserve, Baía Formosa, on 28 December 2002 (FSM); also known from Mata do Mucambo, Goianinha (M. Silva, FSM & JFP pers. obs.), and sound-recorded at Canguaretama (WA 2598721; F. V. Souza). The Vulnerable and declining P. m. niveigularis is endemic to the Pernambuco Centre of Endemism, and in need of taxonomic study (ICMBio / MMA 2018).

Uncommon in remnant patches of Atlantic Forest between Baía Formosa and Natal (Olmos 2003; FSM, JFP & RDL). The Vulnerable H. g. naumburgae is endemic to the Pernambuco Centre of Endemism (ICMBio / MMA 2018).

A rapid song of this tyrannulet was taped at a forest border in the valley of the Catu River (06°20′S, 35°09′W), Canguaretama, on 13 December 2005 (WA 3300921; FSM, identified by RDL & JFP). Also heard singing repeatedly in riverine forest at Mucambo (06°19′S, 35°14′W), Goianinha, on 2 January 2011 (JFP). More recently, an adult and a just-fledged juvenile at a forest border in the same locality (WA 3257427, 3300921; RDL) provided proof of breeding (RDL & FSM).

One of the few species documented by a historical specimen, a male (LSUMZ 10420) taken by J. H. Phares in Natal on 9 September 1945. The demography and life history of this elaenia have been studied in restinga woodland on dunes with ‘tabuleiro’ in Parnamirim (Toledo-Lima 2013). Its citation for the north coast Caatinga, in Macau (Silva et al. 2012), is the only record for that biome in the state and is perhaps in error (FSM & JBI).

Vocalisations exclusively attributable to this species establish its presence in the state, but its status is uncertain. Visual diagnosis is less reliable (Fig. 13). First documented via a sound-recording of its repeated call at Fazenda Malhada Vermelha (06°45′S, 36°40′W; 400 m), Parelhas, on 14 November 2005 (WA 3300894; FSM, identified by RDL), which may suggest local breeding or a late austral spring migrant. Two individuals reported as this species, with brood patches, were caught during the dry season, on 3 May and 25–26 July 1996 at ESEC Seridó, Serra Negra do Norte (Nascimento 2000). At the same locality, mist-netting work suggested the species to be a migrant (Damasceno 2015), nomadic / migratory (C. C. O. Silva et al. 2017) or a seasonal visitor (G. Toledo-Lima). Apart from the November documentation, records suggest the species is present in Rio Grande do Norte in March–August (RDL), i.e. the austral winter. M. swainsoni is a partial migrant, the nominate subspecies being the southernmost taxon, which migrates to northern South America, while sedentary populations in central Brazil may be M. s. pelzelni (Somenzari et al. 2018). Based on analysis of specimens, both subspecies have been found in nearby Ceará (Lanyon 1978).

The typical call of this Myiarchus was first documented at Espírito Santo on 27 May 2018 (WA 2984460; J. Dantas). M. ferox had been observed previously: one calling in shrubby restinga at Barra do Cunhaú, Tibau do Sul, on 26 December 2002; two calling in riverine forest at Mata do Mucambo, Goianinha, on 20 May 2006 (FSM); two heard at an Atlantic Forest / sugarcane plantation ecotone, Baía Formosa, on 28 December 2010; one heard at Mucambo on 30 December 2010; and one heard at Guaju mangroves, Baía Formosa, on 1 January 2011 (JFP). M. ferox was mentioned for the Caatinga by Silva et al. (2012), but specimen COUFRN 40 from this habitat in Macaíba was re-identified as M. tyrannulus by RDL. Although claimed to have been ringed and reportedly resident at ESEC Seridó, Serra Negra do Norte (C. C. O. Silva et al. 2017), we consider its presence there improbable (Pichorim et al. 2016b). We regard the species to be the only Myiarchus restricted to the Atlantic Forest in the state.

One of the commonest passerines in Rio Grande do Norte, especially in almost all Caatinga areas. Less common in the coastal strip, M. tyrannulus was seen in mangroves at Canguaretama on 24 December 2002 (FSM), and was heard in a small patch of Atlantic Forest at Baía Formosa on 28 December 2010 (JFP & FSM). During the rainy season, M. tyrannulus occurs in sympatry with M. swainsoni. For visual identification of these two species, see Fig. 13.

Varela-Freire & Araújo (1997) listed Blue-billed Black Tyrant K. cyanirostris in the dry Seridó region, but we consider this to be a misidentification of K. nigerrimus (see tertiary list in Appendix 1), a species collected in the state (MNRJ 2078) years ago. At Fazenda Salobro Private Reserve (06°13′S, 37°03′W; 400 m), Jucurutu, a female was seen and two males were trapped on 31 December 2008 (FSM). K. nigerrimus has been documented at several other Caatinga sites in the Seridó region, e.g. Parelhas, where adults tended a nestling on 26 April 2016 (WA 2098441; L. Sena), Acari (06°31′S, 36°38′W; 600 m) and Currais Novos (WA 3099923, 3183124; T. Elis). All of the records of females involved birds with large coloured throats (e.g., WA 3194677; T. Elis; FSM), which lead us to conclude that the nominate occurs. If valid, K. n. hoflingae, described from Bahia based on a single female with a thinner striated throat patch, the chin and throat darker than the nominate, and a dusky wing panel, differs from females in Rio Grande do Norte. As it has been incautiously inferred that hoflingae is distributed throughout far north-east Brazil, including Rio Grande do Norte (Farnsworth et al. 2019), we offer here measurements of two adult males trapped in Jucurutu as a basis for comparative study of these taxa: both total length 159 mm; wing chord 91.5 and 92.5 mm (wingtip p4); tail 80.5 and 79.0 mm; tarsus both 21.8 mm; exposed culmen 13.7 and 14.0 mm; bill to nostrils 9.5 and 10.0 mm; gonys 3.8 and 4.0 mm; mass 21.0 and 19.75 g (CEMAVE E79861, E79864).

The only state record of this austral migrant constitutes the northernmost record by c.1,400 km. An adult male was photographed foraging on the ground below a group of Prosopis uniflora trees (Mimosaceae) at the ecotone between dunes and mangroves at Santa Izabel Farm (05°07′S, 36°10′W), Galinhos, on 10 December 2012 (Fig. 14; WA 3065355; C. Ferreira), and was observed again by FSM two days later, foraging under the same trees. Since then, there has been a second record in north-east Brazil, on 17 May 2014, a female present for a month at Caravelas, Santa Bárbara Island, in southernmost Bahia, following strong southerly winds on 26–28 April (WA 1335827; A. Carletti). This species moves north during the austral winter, with records in the states of Paraná, São Paulo, Rio de Janeiro, Mato Grosso do Sul and Mato Grosso in April–November (Somenzari et al. 2018).

The five available state records are all from the period May 2012–June 2013, at three Caatinga localities: Alto do Rodrigues and Macau, on 27 May 2012 and 10 June 2012 (WA 649286, 663484; J. van den Bosch), and ESEC Seridó, Serra Negra do Norte, where it was trapped not only in the austral winter (on 14 July 2012 and 1 June 2013), but also on 26 January 2013, when the region was still dry (C. C. O. Silva et al. 2017). The true status of this species in Rio Grande do Norte is unclear.

The first documented state record, extending the known range c.650 km north-east, is from Punaú, Rio do Fogo, where two were observed on 29 October 2006, and singles on 21 December 2006, 16 August 2008 and 16 November 2013, in recently burned areas (Pichorim et al. 2014a; WA 1689513; B. França). At the same location, one was photographed on 15 and 29 January 2017 (WA 2435098; D. Gurgel, WA 2452371; A. Rafael). Lastly, just to the west, at Pureza, an adult was photographed on 29 June 2018 (WA 3030610; M. Silva). The species frequents this cerrado enclave in the austral winter (June and August) and during the austral spring migration (October–December) but also in January, which might suggest local breeding. Its status in Rio Grande do Norte is still to be clarified.

First documented in Ceará-Mirim on 17 May 2007 (WA 3459903; JBI), this swallow is uncommon in the state, where we know of just 11 records, each involving 1–3 individuals, in February–September. Ten of these, between 30 March and 9 September, during the austral autumn and winter, potentially involve southern South American P. c. patagonica, but the record in February may well represent the nominate form.

Two subspecies occur: the nominate, represented by LSUMZ 10421, taken by J. H. Phares in Natal on 9 August 1945; and P. t. fusca, an austral migrant (Somenzari et al. 2018), photographed in São Miguel do Gostoso on 18 July 2017 (WA 2634379; E. Guilherme). Groups numbering dozens to >300 individuals, including the latter form, have been recorded by JBI, mainly at the landfill of Ceará-Mirim, almost annually since 2005, between March and September (e.g., WA 3459758).

Two with one Blue-and-white Swallow, and a group of Southern Rough-winged Swallows Stelgidopteryx ruficollis, at the landfill in Ceará-Mirim on 17 May 2007, and one with a group of Stelgidopteryx at the same location on 27 September 2007 (Fig. 15A) (JBI), are the first photo-documented records for the state. These correspond to the wintering and prebreeding periods for this austral migrant, which reaches the northernmost limit of its range in Rio Grande do Norte (Moreira-Lima 2013, WikiAves 2019). T. leucorrhoa was reportedly trapped at Salina Diamante Branco, Galinhos, in April 2003 (Araújo et al. 2004), but was said to be resident, rather than a migrant, thereby casting doubt on the identification. The first available proof of occasional overwintering by this species is a photo of an adult at Alto do Rodrigues on 23 May 2012 (Fig. 15B; WA 646156; J. van den Bosch). At least four were photographed together, again in Ceará-Mirim, on 26 June 2013 (JBI).

This austral migrant was photographed by JBI at Ceará-Mirim on 30 May 2011 (Fig. 16), the sole documented record for the state. T. leucopyga had been claimed at Macau on 14 September 2008 (Silva et al. 2012), which would have been a new species for the Caatinga biome, but the photo was ultimately re-identified as a White-winged Swallow T. albiventer (WA 761685). The same authors mentioned a record at Ceará-Mirim, also in September 2008, which they considered to be the first for north-east Brazil, but the record was not documented. They also referred to Pacheco et al. (1996)—for a record of T. leucopyga in Rio de Janeiro—as its northern limit in the austral winter, but the species concerned was T. leucorrhoa. Nevertheless, the formal Brazilian limit for overwintering T. leucopyga was considered to be Rio de Janeiro (Somenzari et al. 2018, WikiAves 2019), consequently the documented record in Rio Grande do Norte is the northernmost by c.1,900 km.

First noted in 2001 at Povoado de Sítio, Ceará-Mirim, and repeatedly observed there, where it was collected by M. Silva in 2007 (COUFRN 14). At least seven, one of which sang and a pair that duetted, in the same floodplain on 7–8 July 2007 (FSM & M. Silva). The photo of an adult male singing on 8 April 2010 was taken at this sole locality in the state (WA 279016; B. França).

The nominate subspecies is an Atlantic Forest endemic (Moreira-Lima 2013). In Rio Grande do Norte, the species was first observed in mixed-species flocks with White-flanked Antwren Myrmotherula axillaris, White-fringed Antwren Formicivora grisea, Plain Antvireo Dysithamnus mentalis, Pectoral Antwren Herpsilochmus pectoralis, Planalto Slaty Antshrike Thamnophilus pelzelni, Black-cheeked Gnateater Conophaga melanops and Plain Xenops Xenops minutus at Mata da Estrela Private Reserve, Baía Formosa, on 14–15 December 2002 (FSM). Ramphocaenus was first documented by a sound-recording at this sole state locality on 12 March 2016 (WA 2270254; D. Gurgel).

Not previously suspected to occur in the state, this thrush has been documented four times in the 21st century, during the austral winter: an adult male without a whitish chin (i.e. of the nominate subspecies) ringed by G. Segurado and photographed by B. França at Macaíba on 14 June 2008 (Silva et al. 2012), at the ecotone of Caatinga / Atlantic Forest; several of both sexes trapped, of which two females were collected in restinga during a study in 2012–16 (Fig. 17); and an adult female photographed at Natal on 12 April 2015 (WA 1662001; D. Gurgel). The nominate race is endemic to the Atlantic Forest (Moreira-Lima 2013), and its complex migratory status, including seasonal altitudinal movements, remain to be clarified (Somenzari et al. 2018).

First ringed in the state at Vila Industrial Alcanor, Macau, in May 1988 (D. Souza) at the end of the rainy season in the Caatinga, i.e. the early austral winter. A fresh-plumaged youngster with pointed tail feathers, some evidence of moult on its breast, thighs and vent, mass 60.25 g, and a very young individual (mass 61.5 g) were trapped at Serra das Queimadas, Parelhas, on 9–10 June 2006, suggesting local breeding (Fig. 18). One full-plumaged adult (mass 63 g) with a brood patch, and another full-plumaged adult (55 g) were caught on 10 and 11 March 2007 at the same location, at the start of the austral winter. Also, a heavily speckled juvenile (55 g) was trapped on 8 May 2009, and an adult female (53.5 g) with a brood patch, ringed on 9 May 2009, was recaptured with a well-developed brood patch, mass 57 g, on 19 January 2010, just over eight months later, all at Pimenteira in the Serra de Santana, Santana do Matos (FSM). In lowland Caatinga, singing birds and adults in nuptial plumage were recorded in January–April (FSM), and five with brood patches were captured in Mossoró (Cavalcanti et al. 2016). In Rio Grande do Norte, this thrush forms local concentrations in the austral winter, e.g., c.100 birds in 4 ha of low restinga at Maxaranguape on 4 August 2015 (FSM); these were presumably either austral migrants or a seasonal gathering of residents at a rich food source. This species occurs year-round in north-east Brazil (Somenzari et al. 2018). The latter authors considered that records in this region do not suggest migratory behaviour, probably due to the co-existence of resident / migratory populations—which we believe to be true—but we note that, at least in Rio Grande do Norte, nesting is better established than the arrival of austral migrants.

The breeding biology of the species was studied in restinga on the campus of the Federal University in Natal during 2006–07 (unpubl. study by L. M. C. Dantas et al.). It is also a common breeder in the Caatinga, illustrated by a nest at Fazenda Salobro Private Reserve (06°13′S, 37°02′W; 400 m), Jucurutu, on 23 March 2017 (Fig. 19). Populations in north-east Brazil have traditionally been treated as M. s. arenaceus, but this subspecies is diagnosed only by its longer bill (Hellmayr 1934). A modern taxonomic analysis would be welcome.

This cacique breeds around Baía Formosa, as reported by local people to FSM and revealed by photos (WikiAves 2019). It is possibly a feral population, still being reinforced by released cagebirds. A former colony in Ceará-Mirim was persecuted to extinction (M. Silva) and another colony at Nísia Floresta in the 1980s also no longer exists (DMH).

The first mention in the state is from August 2010 (Pichorim et al. 2016a). Documentation of immatures in transitional plumages (WA 2164752; J. van den Bosch, WA 2641146; S. Furtado) establishes the species on the primary list. Reported to have recently invaded eastern Brazil (ICMBio / MMA 2018), and that is perhaps true for Rio Grande do Norte too but, based on WikiAves records (to 31 March 2019), it occurs only in March–September, suggesting the species is an austral winter visitor.

Two specimens from the state: UMMZ 113609, taken by E. W. van Aken in Natal on 19 February 1945; and an undated female (COUFRN 705) from the restinga at Parnamirim (MP). The species has been recorded almost throughout the east coast, including: an adult in shrubby restinga at Barra do Cunhaú (06°18′S, 35°02′W), Tibau do Sul, on 26 December 2002; an adult in low-stature Atlantic Forest at Dunas de Natal State Park, Natal, on 24 November 2004 (FSM); up to five in cerrado at Punaú (05°23′S, 35°30′W), Rio do Fogo (Pichorim et al. 2014a, where a photo was published); and in ‘tabuleiro’ at Jundiaí (05°53′S, 35°23′W), Macaiba (Silva et al. 2012). A sighting in the Caatinga at Macau (Silva et al. 2012) is the only record for this biome in the state, but escaped / released cagebirds may be the origin (FSM pers. obs.).

Interviews with local people by FSM confirmed this finch was formerly numerous in the state (Faria 2001). It is still very sought after by the cagebird trade, filling many of the environmental agency's rehabilitation centres throughout north-east Brazil. It is regularly released by the environmental police without identifying the subspecies concerned, probably leading to some genetic mixing between S. f. brasiliensis, the native local taxon, and S. f. pelzelni.

Individuals frequent the restinga of Parnamirim and Natal (P. Vitor), but breeding is unknown (MP), and environmental agents regularly release cagebirds (FSM). Birds recorded in restinga and in mangroves at Baía Formosa and Atlantic Forest borders at Goianinha probably represent remnant native populations (JFP & FSM).

A pair was photographed in the floodplain of the Pirangi River, at Cotovelo, Parnamirim, on 1 May 2008 (JBI), at the start of the local rainy season. A male S. l. cinereola was photographed at Nísia Floresta on 28 August 2017 (WA 2676962; F. E. Silva, identified by FSM), at the end of the local rainy season. The so-called ‘chorão' or ‘patativa’ is much sought after by traffickers in the state (Pichorim et al. 2016b, FSM pers. obs).

Recently proven to occur in the north-west of the state: a photo of a moulting male singing at Assu on 26 June 2017 (WA 2658215; M. Silva), and a photo and sound-recording of a singing adult at Sítio do Góis, Apodi, on 11 March 2018 (WA 2908958, 2909323; J. Souza).

This exotic invasive species, present in Natal since 1985 when it was seen building a nest (C. Medeiros), is currently common along the east coast but scarce in the dry interior of the state (FSM pers. obs.; WikiAves 2019).

Introduced from the Old World, and currently common throughout the state. The nominate is the only subspecies known to occur in Brazil (Piacentini et al. 2015).

The first published state record (Olmos 2003) lacked documentary evidence, and two other references to the species stemmed from interviews with local people (Silveira & Varela-Freire 1999, Pichorim et al. 2016a). It was heard and seen at ESEC Seridó, Serra Negra do Norte (JBI), but was not documented, and this is the sole record to support its inclusion in the Caatinga bird list for the state (Silva et al. 2012) along with that for the same locality (Pichorim et al. 2016b).

Ten ringed in the USA and Canada between 1955 and 1971 were recovered in nine municipalities in the state between 1959 and 1975 (Mestre et al. 2010), but there is no documentary evidence to support these records (CEMAVE pers. comm., BBL pers. comm.). Subsequently, the species has not been recorded again in Rio Grande do Norte.

A rock painting at ‘Pedra Ferrada’, São Rafael, has been attributed to this species (Sick 1997: 227). An adult was present at Salina Diamante Branco, Galinhos, over five consecutive days in March 2001 (Azevedo et al. 2004), but went undocumented.

Two weakened immatures, one beached on 7 August 2008 in Natal, the other captured at sea off Natal on 13 August 2008, were found during an influx of this penguin along the Brazilian coast due to a severe austral winter (Dantas et al. 2013). Both subsequently died, but the frozen specimens (COUFRN 28, 30) were lost due to an electricity outage.

An albatross found beached on the north coast of the state, in May 2018, was rehabilitated and released on about 20 December 2018 (F. Lima pers. comm.). Two photos of the bird were used to publicise an educational project, in which it was identified as a Black-browed Albatross T. melanophris. In fact, the dark bill with clear yellow-green culmen identify this immature as T. chlororhynchos (Bugoni & Furness 2009). The species is maintained on our secondary list because the documentary evidence is not available. This is the only known state record, but one of many in north-east Brazil, e.g. one seen 55 km north-east of the Fernando de Noronha archipelago on 15 November 1996 by A. B. S. Fuchs (J. M. R. Soto, MS); 37 found beached on the north coast of Bahia in 1994–98 (Lima et al. 2004); an immature off Salvador, Bahia, on 25 May 2009 (WA 156301; B. Rennó); and an immature 45 km off Paracuru, Ceará, on 5 January 2018 (WA 2842425; C. E. Moura). Endangered T. chlororhynchos occurs along most of the Brazilian coast (ICMBio / MMA 2018), and our partial compilation of records confirms that immatures are reasonably regular off the northeast of the country.

This pelagic species, which breeds in Macaronesia, is believed to occur off the state's coast as a result of the use of dataloggers to track the tiny population (Zino et al. 2011, Ramos et al. 2016), but lacks confirmation through direct observation.

Like the previous species, occurrence off the state's coast is based on information gathered from dataloggers (Ramirez et al. 2013, Ramos et al. 2016), but lacks confirmation through direct observation.

The occurrence of this pelagic species off Rio Grande do Norte is also based on information gathered from dataloggers (Ramos et al. 2015, Cruz-Flores et al. 2019), but lacks direct confirmation.

This shearwater, endemic to the Cape Verde Islands, is believed to occur off the state's coast in the non-breeding season (Zajková et al. 2017), but this discovery, which is based on information garnered from dataloggers, lacks direct confirmation. P. boydi was split from Macaronesian Shearwater P. baroli, itself split from Little Shearwater P. assimilis (Gill & Donsker 2019), but is treated as a subspecies of Audubon's Shearwater P. lherminieri by some authorities (Carboneras et al. 2019). Like Pterodroma madeira, P. deserta, and Bulweria, because of the relative accuracy of geolocators (+/- 200 km), it is impossible to be sure if this shearwater occurs in the state's continental waters, which reach only 27–40 km from the coast.

One, beached south of Natal, was kept by A. Varela-Freire between September 1986 and December 1987 (Varela-Freire 1997) but not documented. A weak individual floating in the sea off Guamaré in early March 2019 was photographed by A. Gleydson, but the photo is unavailable (RDL & FSM).

One flushed by FSM from the almost-dry stony bed of Salobro stream, with still a few seasonal ponds and flanked by gallery forest, in Martins on 4 August 2010, was not documented. The species is known from nearby localities in neighbouring Ceará, Paraíba and Pernambuco (Pereira et al. 2012, WikiAves 2019). More records are expected in Rio Grande do Norte.

This conspicuous ibis was seen once in the Seridó region around 1996, but not in ‘açude Riacho do Roçado' as claimed by Medeiros et al. (2000; A. da Silveira pers. comm.). This record supported the species’ inclusion in the first state bird list (Varela-Freire et al. 1999). T. caudatus is now considered extinct on the north coast, based on interviews with local people by FSM that indicated its presence until the 1950s at Macau and Guamaré, where it was regularly hunted. Now rare in north-east Brazil, where absent from Rio Grande do Norte to north-west Ceará and from almost all of the Caatinga (WikiAves 2019); it is no longer expected in the state.

Considered rare in the first state bird list (Varela-Freire et al. 1999), but there is no information concerning the origin of the claimed record. A bird perched on electric wires along the unsurfaced road to Morro Vermelho (05°59′S, 35°10′W), Nísia Floresta, on several consecutive days in 2004, was finally shot and buried there (C. Ferreira pers. comm.). The nearest records to Rio Grande do Norte are from Pernambuco; individuals on 15 October and 4 December 1999, possibly of a resident population (Roda & Pereira 2006), and on 17 October 2009 (Pereira et al. 2014). Records in central-north Ceará on 25 November 2007, and Alagoas on 19 October 2018 (WikiAves 2019), suggest migration as well; thus, further state records can be expected.

Around 1998, a weak Sungrebe (identified by DMH) was brought to Pipa Ecological Sanctuary, Tibau do Sul, where it died some days later but was not documented. An uncommon resident in the Atlantic Forest (Moreira-Lima 2013); because our record lacks information as to the locality where it was found, it may not have been in Rio Grande do Norte.

An immature bird, probably a Hudsonian Godwit, was seen at Salina Soledade, Macau, on 22 June 2005 (Irusta & Sagot-Martin 2011), but not documented. Autumn migration passes inland (west) of north-east Brazil and in spring the species uses few or no stopover sites (Somenzari et al. 2018); thus, the species is not expected in Rio Grande do Norte.

Seen twice in the state: one in a flock with 14 American Whimbrels N. hudsonicus, seen both perched and flight at Canto do Amaro mangroves, Guamaré, on 9 October 2010; and one in a flock with c.160 N. hudsonicus flushed from mangrove islets (05°50′S, 35°17′W) in Macaíba on 18 February 2016 (FSM). There is no documentary evidence, but N. phaeopus has been repeatedly documented on Fernando de Noronha (Silva e Silva 2008), and more state records can be expected.

One, banded in 1984 in Berlin, Germany, and therefore of the nominate subspecies, was recovered at Macau in September 1986 (Sick 1997: 335). Although C. n. surinamensis is the only subspecies admitted by Piacentini et al. (2015), these authors note, based on the Macau record, that the nominate is also expected in Brazil, and surinamensis should occur in Rio Grande do Norte.

An adult perched atop a 15 m-tall tree was seen in riverine forest along Mucambo stream (06°19′S, 35°14′W), Goianinha, on 21 January 2019 (FSM), but was not documented. Given that it occurs at neighbouring localities in Paraíba, the species was expected in the state.

A probable Ruddy Quail-Dove was heard singing at Mata da Estrela Private Reserve, Baía Formosa, on 29 December 2002, and two others, probably a pair of this species, were flushed at a forest border in Estivas Private Reserve, Canguaretama, on 12 December 2005 (FSM). The species is expected in Rio Grande do Norte, with the nearest documented record in neighbouring Mamanguape, Paraíba, on 12 May 2015 (WA 1694065; E. Barreto).

The species has been observed, but not documented, in coastal dunes at Natal (Varela-Freire et al. 1999), but we are unable to find any record to support this assertion, and due to the lack of surface water and paucity of tall trees we believe Dunas de Natal State Park does not harbour the species (FSM pers. obs.). Nevertheless, there is a suitable habitat in the Atlantic Forest of south-east Rio Grande do Norte. It is found very nearby at Mamanguape in far north-east Paraíba (Pinto & Camargo 1961, WikiAves 2019), so it can be expected in the state.

The song of this owl was heard at Casqueira forest (06°24′S, 35°04′W), Baía Formosa, on 26 January 2015 during a full moon (FSM), but was not sound-recorded. The nearest documented records are from Pernambuco (Roda & Pereira 2006) and to the north, as far as Pará.

We know of two trustworthy records in the state: one responding to playback on two nights at ESEC Seridó, Serra Negra do Norte (Pichorim et al. 2016b); and one heard at Cerro Corá in July 2017 (D. Oliveira), but there is no documentary evidence.

All Brazilian records, including those photo-documented or sound-recorded, are in September–April, and C. m. chapmani overwinters in central Brazil and northern Argentina (Somenzari et al. 2018). Even photo-documented records require careful analysis due to the difficulty in separating C. minor from C. acutipennis. Two photos of birds perched on branches, at Parelhas on 12 March 2006 (WA 344901; L. Sena) and Macau on 18 March 2015 (WA 1640227; J. Dantas), could pertain to either of these species. C. minor appears rather common at Chapada do Araripe, in southern Ceará, where MNRJ obtained an adult female on 15 March 1989 (Teixeira et al. 1993). The other nearest documented record is a photo of one perched at Aquiraz, in northern Ceará, on 16 February 2006 (WA 1947161; A. Campos). Although its main migration route lies west of Rio Grande do Norte, C. minor is likely to be found in the state, especially in the ‘serras’ and mangroves.

Seen twice at Engenho Mucambo, Goianinha—one foraging with two Fork-tailed Palm Swifts Tachornis squamata and several Barn Swallows Hirundo rustica on 5 November 2006 (FSM & MP); and one vocalising over the forest on 30 December 2010 (JFP)—which suggests it is a potential breeder, but documentary evidence to establish its occurrence in the state is lacking.

An adult male was observed and its song heard at Mata do Mucambo, Goianinha, on 30 December 2010, and the species was heard again there on 2 January 2011 (JFP), but not documented.

Included in a bird list for Baía Formosa (Olmos 2003), without documentation. Two females, both showing a subterminal dark band on the open tail, were observed by FSM but not documented: at Dunas de Natal State Park, Natal, on 28 November 2002; and mobbing a male Ruby-topaz Hummingbird Chrysolampis mosquitus that was competing with it for flying insects at the border of restinga at Morro Vermelho, Nísia Floresta, on 17 November 2004.

Heard by FSM at Mata da Estrela Private Reserve, Baía Formosa, on 3–4 January 2003, but not documented. Heard at the same locality on 28 February–7 March 2003, where judged uncommon and said to have been sound-recorded (Olmos 2003); however, the observer confirmed that the species was only heard (F. Olmos pers. comm.).

One heard singing and two seen at Mata do Mucambo, Goianinha, on 2 January 2011 (JFP & FSM), but not documented.

Recorded at Baía Formosa during a survey on 28 February–7 March 2003 (Olmos 2003), but not documented and the species has not been encountered again in this area.

Identification of Myiobius can be difficult (Ridgely & Tudor 2009). The first mention of this genus in the state pertained to Black-tailed Flycatcher M. atricaudus seen at Mata da Estrela Private Reserve, Baía Formosa (Olmos 2003). However, records attributed to this species in the Pernambuco Centre of Endemism are likely to reflect misidentification for M. barbatus, which occurs—albeit not in sympatry with atricaudus—in the far north-east Brazilian Atlantic Forest, whereas atricaudus is found in ‘brejos de altitude’ in the Caatinga (RDL pers. obs.). Eight specimens of M. barbatus were collected in Paraíba at the border with Rio Grande do Norte in 1957 (Pinto & Camargo 1961), and one, presumably this species, was recently photographed at Mata do Pilão, Espírito Santo (WA 3002212; F. V. Souza), but is not definitely identifiable, and we therefore include the species only on the secondary list. A recent phylogeny of the genus reveals that a specimen of barbatus collected in the Pernambuco Centre of Endemism—presumably M. b. mastacalis—is sister to the nominate from the Guiana Shield (Azevedo 2017), therefore matching the pattern of several species from the same centre of endemism whose populations are more closely related to those in Amazonia than to the Atlantic Forest south of the São Francisco River (Teixeira 1987, Silveira et al. 2003).

One was heard at Mata do Mucambo, Goianinha on 30 December 2010, and it sang at the same place on 2 January 2011 (JFP), but was not documented.

Three undocumented records: one Cnemotriccus-like tyrant-flycatcher, but with a pale-based bill and long ochre supercilium, perched on a Sideroxylon obtusifolium (Sapotaceae) on a sand dune, along with two or more Chilean Elaenias E. chilensis—presumably on austral autumn migration—at Guamaré on 27 April 2012 (FSM); one at the ‘serra' of Venha-Ver (06°19′S, 38°26′W) in July 2012 (Mariano 2014); and one at the ‘serra' of Martins sometime in 2016 (D. Oliveira). This species, partially migratory in Brazil (Somenzari et al. 2018), is expected in the state during the austral winter, and may also be resident in the ‘serras’ of the state, as it is at Serra de Baturité, Ceará (RDL pers. obs.).

Much sought after by traffickers and historically released by state environmental agents; one, sound-recorded (WA 3257831, 3257841) at Mata do Mucambo, Goianinha, on 20 January 2019, probably originated from a release and is therefore of unknown origin (RDL & FSM). This locality had previously been studied by ornithologists, without any records of this species until at least 2011, thereby reinforcing the hypothesis of a released or escaped individual.

This Vulnerable species was included as rare in the first state bird list, being specifically mentioned for Agreste (Atlantic Forest / Caatinga ecotone) and the Caatinga (Varela-Freire et al. 1999), but we have found no specific records. A claimed first documented record at Florânia (Silva et al. 2011) was misidentified and consequently invalid (WA 295444). In the most recent Brazilian Red List (ICMBio / MMA 2018), the species is mapped for two localities in the state, one being the incorrect record just mentioned, while the source of the other is unknown to us. Although rare or disappeared today, the species is well known to those inhabitants interviewed (Pichorim et al. 2016a; FSM pers. obs.). It is expensive on the black market, and males are much sought after to cross with the canary, Serinus canaria, to produce the hybrid ‘pintagol’, an excellent singer and consequently the target of systematic trapping in the state. Its tendency towards extinction has been offset since at least 1999 via releases (Dr A. Leite, Cetas / IBAMA Natal, pers. comm.), and today the environmental police immediately release any birds confiscated from traffickers.