Systematics

Monotypic; no geographic variation.

Tumbes Swallow was described as Hirundo leucopygia by Taczanowksi (1880), based on four specimens collected by Stolzmann in 1878 at Chepen, Peru. The type specimen, formerly in the Museum and Institute of Zoology, Warsaw, has been lost (Sztolcmann and Domaniewski 1927), although other specimens from the original series survive in other institutions (Hellmayr 1935). The name leucopygia is preoccupied, however, and so Philippi (1902) proposed a new name, stolzmanni, for this species.

Hellmayr (1935) classified stolzmanni as a subspecies of Tachycineta albilinea (Mangrove Swallow). This classification was adopted by other authorities for many years (e.g. Peters 1960, Meyer de Schauensee 1966), although during this period some authors suggested that stolzmanni merited species status (e.g. Ridgely and Tudor 1989, Robbins et al. 1997).

Recent molecular work clarifies the relationships of Tachycineta, based in DNA sequence data from six mitochondrial genes: cytochrome b, the second subunit of nicotinamide adenine dinucleotide dehydrogenase, cytochrome oxidase II, ATPase 8, tRNA-lysine, and tRNA-methionine (Whittingham et al. 2002). The resulting phylogeny recovers two main clades within Tachycineta. The South and Central American clade is made up of two superspecies, the first consisting of stolzmanni, albilinea, and White-winged Swallow (T. albiventer), and the second of White-rumped Swallow (T. leucorrhoa) and Chilean Swallow (T. meyeni). The North American and Caribbean clade consists of Tree Swallow (T. bicolor), Violet-green Swallow (T. thalassina), Golden Swallow (T. euchrysea), and Bahama Swallow (T. cyaneoviridis). Whittingham el al. (2002) also found that albilinea and albiventris are sister taxa and more closely related to each other than either is to stolzmanni. This work also suggests that Tachycineta is a relatively old group compared to other New World swallow genera (Whittingham et al. 2002).