Austral migrant tyrant-flycatchers

During the austral spring (September and October), large numbers of migratory birds arrive in the Atlantic Forest and across southern South America to breed. Avian migration in South America is very poorly understood compared to many other parts of the world, with seasonal distribution and migration routes unclear for many species. However, some species, particularly some tyrant-flycatchers, are known to migrate very long distances, and a few are potential vagrants to North America and perhaps beyond.

Several Fork-tailed Flycatchers (photo 1) are currently about on agricultural land around REGUA. There are four races of this stunning bird, and the nominate Tyrannus savana savana is a long distance migrant, breeding in southern South America, mainly south of the Tropic of Capricorn², and spending the austral winter (April to August) in the northern half of the continent, as far north as western Columbia, Venezuela, and Trinidad and Tobago. Fork-tailed Flycatcher occurs almost annually as a vagrant in the US and Canada with over 120 records, mainly in the east and involving 1st winter birds of the nominate race³. Most have occurred as reverse migrants in September and October, when birds wintering in northern South America move south to their breeding grounds, but some have occurred as overshoots in the northern spring when birds are heading north for the austral winter. Incredibly, one even made it to Spain in October 2002³!

Fork-tailed Flycatcher of the nominate form T. s. savana, REGUA, November 2011.
This long distance migrant is recorded almost annually as a vagrant in North
America, and the first record for the Western Palearctic occurred in 2002.

Variegated Flycatcher (photo 2) is also a common summer visitor to the Atlantic Forest and can be seen around the wetland and at forest edge habitats at REGUA at the moment. Widespread throughout South America east of the Andes, nominate Empidonomus varius varius is highly migratory in the southern part of its breeding range, with birds moving as far north as Trinidad, Venezuela and as far west as eastern Colombia and eastern Ecuador for the austral winter. Variegated Flycatcher shows a similar pattern of vagrancy in North America to Fork-tailed Flycatcher, albeit but with far fewer records (Fork-tailed Flycatcher is a very conspicuous species, so maybe Variegated Flycatchers are going unnoticed?) - 3 have been recorded in the US (2 in the east) and 1 in south-east Canada, with all but one recorded between September and November. None have been assigned to race for certain, but a bird in Washington in 2008 showed characteristics of the nominate varius⁴, suggesting migrants from southern South America are involved rather than the nearer but sedentary Mexican population. With Fork-tailed Flycatcher having made it across the Atlantic, could Variegated Flycatcher follow?

Variegated Flycatcher of the highly migratory nominate race E. v. varius, REGUA,
October 2007. Birds breeding in southern South America winter in the far north of
the continent. 4 have so far occurred in North America, including 3 in the east, but
more possibly go unnoticed. The larger size, longer bill and rufous tail separate it
from the similar Piratic Flycatcher.

Piratic Flycatcher is similar to Variegated in appearance, but is smaller with a shorter bill and less rufous tones in the tail and rump. Like Variegated, the nominate L. l. leucophaius is migratory and moves north for the austral winter. Nine had been recorded in North America up until 2009⁴, with one record from eastern US (Florida). Similarly, the local race of Streaked Flycatcher, M. m. solitarius (photo 3), is also highly migratory in the southern end of its range. So far Streaked Flycatcher has not been recorded north of Mexico⁴, but this is one of the most common austral summer migrant tyrant-flycatchers in RJ state, and must be considered a potential vagrant to North America.

Streaked Flycatcher of the migratory race M. m. solitarius, Vale das Taquaras,
November 2007. This common long distance austral migrant is a potential vagrant
to North America and maybe elsewhere.

References

¹ del Hoyo, J., Elliot, A. & Christie, D. (eds.) 2004. Handbook of the Birds of the World, 9. Barcelona: Lynx Edicions.
² Erickson, H.T. 1982. Migration of the Fork-tailed Flycatcher through southeastern Brazil. American Birds 36: 136-138.
³ Gutiérrez, R. 2008. The Fork-tailed Flycatcher in Spain - a new Western Palearctic bird. Birding World 21: 325-328.
⁴ Mlodinow, S.G. & Irons, D.S. 2009. First Record of the Variegated Flycatcher for Western North America. Western Birds 40: 47-50.