Bahama Swallow Tachycineta cyaneoviridis

  • Order: Passeriformes
  • Family: Hirundinidae
  • Monotypic
  • Authors: Gaelyn Ong
Sections

Appearance

Distinguishing Characteristics

Dorsal view of Adult Bahama Swallow, Grand Bahama Island, 15 May 1995, © Paul E. AllenBahama Swallows, like other members of Tachycineta, are bicolored, with green and blue upperparts and white underparts.  The most distinctive feature of this species is the long, deeply forked tail.

Similar Species

The Bahama Swallow is superficially similar to another species of Tachycineta, the Tree Swallow (T. bicolor), which is an uncommon migrant through the Bahamas and a common winter resident on Cuba. The Tree Swallow has a shorter tail, which is notched but is not deeply forked. The auriculars of the Tree Swallow are dark, whereas on the Bahama Swallow the auriculars are white. The Tree Swallow has more uniformly colored, blue upperparts, lacking the contrast in Bahama Swallow between the color of the crown and back (green) with the wings and tail (blue). Also, the two species differ in the color of the underwing coverts, which are white in the Bahama Swallow and gray in the Tree Swallow. Juvenile Bahama Swallows are duller, with a less deeply forked tail, and so are more similar to juvenile Tree Swallows. Juvenile Bahama Swallows also do not have the white underwing coverts of the adult, although the rest of the underparts usually are pure white (lacking the brown pectoral band, often present on juvenile Tree Swallow). Juveniles of the two species differ in the pattern of the auriculars, as described above the adults: white or mostly white in Bahama Swallow, dark or mostly dark in Tree Swallow.

For additional details on field identification of Bahama Swallow, see Smith and Smith (1990).

Detailed Description

Grand Bahama Island, 15 May 1995, © Paul E. Allen

Adult female Bahama Swallwo, dorsal view. Grand Bahama Island, 15 May 1995, © Paul E. Allen

16 day chick, Grand Bahama Island, 28 May 1995, © Paul E. AllenThe following description is based on Ridgway (1904):

Adult: Medium sized swallow with long, strongly graduated tail. Crown, nape back and scapulars dull metallic green. Lesser wing coverts, rump and uppertail coverts bluish green.  Median and greater wing coverts and tertials dusky greenish blue, with broad, lighter greenish blue or bluish green margins.  Remiges and rectrices dark greenish blue. Lores dusky.  Auriculars, malars, underwing coverts, and entire underparts pure white.  Female similar to male, but more or less duller in color; auriculars mottled with grayish brown; and tail shorter, with a slightly shallower fork.

Juvenile: Upperparts brown above with a green sheen, which is most pronounced on the wing coverts and mantle; head and upper tailcoverts more sooty brown.  Auriculars and entire underparts white, except for a patch of sooty brown on the sides of the upper breast.

Molts

Molt has not been examined critically however Dwight (1900) noticed that the specimens collected in the United States showed no signs of molt and assumed that molt occurs in late summer and early autumn, as with the congeneric Tree Swallow (T. bicolor).

Bare Parts

Iris brown; bill black; tarsi and toes brownish black or blackish brown.

Measurements

Total length:  15 cm (Brudenell-Bruce 1975, Turner and Rose 1989, Turner 2004), 15.5 cm (Raffaele et al. 1998)

Linear measurements (from Ridgway 1904):

Wing length, male: mean 115 mm (range 113-117 mm, n = 7)

Wing length, female: mean 107.5 mm (range 105-190 mm, n = 4)

Tail length, male: mean 67.9 mm (range 66-73 mm, n = 7)

Tail length, female: mean 59.5 mm (range 59-61 mm, n = 4)

Depth of tail fork, male: mean 27.1 mm (range 25-31 mm, n = 7)

Depth of tail fork, female: mean 20.5 mm (range 19-22 mm, n = 4)

Bill (exposed culmen), male: mean 6.4 mm (range 6-7 mm, n = 7)

Bill (exposed culmen), female: mean 6.7 mm (range 6.5-7 mm, n = 4)

Tarsus, male: mean 11.8 mm (range 11.5-12 mm, n = 7)

Tarsus, female: mean 11.5 mm (range 11-12 mm, n = 4)

Mass (from Steadman et al. 1980):

Males: mean 17.5 g (n = 4: 16.3, 16.9, 17.4, 195. g)

Females: mean 17.9 g (n = 2: 17.3, 18.5 g)

Undetermined: mean 17.1 g (n = 2: 16.6, 17.6 g)

Recommended Citation

Ong, G. (2010). Bahama Swallow (Tachycineta cyaneoviridis), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.bahswa.01