Justification of Red List Category
This species has recently been discovered at a number of new locations; however its range is still small and severely fragmented by ongoing extensive habitat loss, and the small population is likely to be declining rapidly. It consequently qualifies as Vulnerable.
The population is estimated to number 1,000-2,499 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.
This species is suspected to be declining rapidly, in line with rates habitat loss within its range.
Onychorhynchus swainsoni is confined to the dwindling forests of east Brazil (Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina and possibly an old record from Goiás), where it was very poorly known. It has not been recorded in the Serra dos Órgãos (Rio de Janeiro) at least since 1940s (Mallet-Rodrigues et al. 2007). However, there have been recent records from at least seven new sites in Paraná (Mitroszewski et al. 2004; Mikchi and Bernils 2004) and four new sites in São Paulo (F. Olmos in litt. 2004; L. F. Silveira in litt. 2004; Buzzetti 2000), with the spread of records suggesting a fairly continuous extent of occurrence along the Atlantic forest belt in eastern São Paulo and Paraná, from the border with Rio de Janeiro to at least Guaratuba bay, and inland to the Ribeira valley and Paranapiacaba and Mantiqueira ranges (F. Olmos in litt. 2004). In Santa Catarina state it was known only historically until 2006 when one was seen at Volta Velha (Mallet-Rodrigues et al. 2006). A report of its occurrence in south-east Paraguay (Graves (1990) is erroneous (M. S. Foster in litt. 2000). Three areas are particularly important: near Estacão Vera Cruz, south Bahia, Itatiaia National Park, Rio de Janeiro/Minas Gerais, and a number of sites in the Serra do Mar, São Paulo.
It inhabits the understorey of lowland and lower montane Atlantic forest where it often perches motionless for long periods. At Intervales State Park, it is found most frequently in the proximity of small watercourses (L. F. Silveira in litt. 2000). The diet appears to be insectivorous. It sometimes joins mixed-species flocks and has been noted associating with foliage-gleaners (R. S. R. Williams verbally 1998) and fire-eyes (G. M. Kirwan in litt. 1999). A juvenile has been seen in January in Rio de Janeiro, suggesting breeding in the austral spring. At Intervales State Park nest-building was recorded during October, and two eggs were laid in November (A. C. De Luca in litt. 2007; Kirwan 2009).
The widespread clearance, degradation and fragmentation of the Atlantic forest are the principal threats to this naturally rare tyrannid.
Conservation Actions Underway
It is known from several protected areas, including: Monte Pascoal (G. M. Kirwan in litt. 1999), Itatiaia and Serra da Bocaina (J. M. Goerck verbally 2000) National Parks, Intervales State Park (L. F. Silveira in litt. 2000), Ubatuba Experimental Station (A. Whittaker in litt. 2000), the Guaricana Forest Reserves (Guaratuba and Morretes) (F. Costa Straube in litt. 2000), Salto Morato private reserve (Guaraqueçaba) (Mikchi and Bernils 2004), Pico do Marumbi State Park (Mikchi and Bernils 2004), Saint Hilaire-Lange National Park (Mikchi and Bernils 2004), Fazenda Monte Alegre private reserve, and a private reserve at Piquete (F. Olmos in litt. 2004).
16-16.5 cm. Large-billed flycatcher, with spectacular, but rarely seen, crest. Largely uniform dull brown upperparts with pale, bright cinnamon rump and tail. Whitish throat, with rest of underparts ochraceous buff and no breast markings. Striking crest is usually left flat, imparting hammerhead shape to head, but when raised is remarkable combination of scarlet, black and blue (yellow replaces red in female). Voice Clear pree-o, reminiscent of a jacamar or manakin.
Text account compilers
Clay, R., Harding, M., Pople, R., Sharpe, C J, Symes, A., Williams, R.
Williams, R.S.R., Kirwan, G., Whittaker, A., Foster, M.S., Silveira, L., Develey, P., De Luca, A., Mallet-Rodrigues, F., Goerck, J., Olmos, F., Costa Straube, F.
BirdLife International (2018) Species factsheet: Onychorhynchus swainsoni. Downloaded from http://www.birdlife.org on 20/06/2018. Recommended citation for factsheets for more than one species: BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/06/2018.