Galapagos Rail Laterallus spilonota

  • Order: Gruiformes
  • Family: Rallidae
  • Monotypic
  • Authors: Evan Hill
Sections

Appearance

Distinguishing Characteristics

Galapagos Rail is a diminutive bird, about 15 cm in length. It has a dark gray head and lower parts with narrow white barring covering the flanks and thighs. The interscapulars, scapulars and upper back are chestnut brown. The upper wing coverts also are brown, and may or may not have white spotting. The iris is a distinctive red, and the bill, tarsi and toes are brown.

Similar Species

Black Rail (Laterallus jamaicensis) is similar in size and coloration to Galapagos Rail (Eddleman et al. 1994). Adults of both species are 10-15 cm in length and have a distinctive red iris and dark plumage (Harris 1982, Eddleman et al. 1994). Although all Black Rails show white spotting, not all Galapagos Rails are spotted (Franklin et al. 1979). Black Rails are slightly lighter at 36 g than Galapagos Rails, which can weigh as much as 45 g (Franklin et al.1979, Eddleman et al. 1994). The deep, semi-domed nest cup is also characteristic of each species (Bent 1926). Black Rail’s kickee doo call is reminiscent of the last few syllables of Galapagos Rail’s chichichichichurr call, but the difference is easy to recognize with experience.

Detailed Description

Ridgway and Friedmann (1941) provide a detailed description of Galapagos Rail, which is paraphrased here.

Adult: The sexes are similar. The head and lower parts are neutral gray to deep neutral gray, slightly darker gray on the top of the head. The flanks, thighs, and undertail coverts go from a deep neutral gray to dark neutral gray to a dusky black. There also is sparse, nNarrow, whitish barring also covers the flanks and thighs. Interscapulars, scapulars, and upper back go from argus brown to chestnut brown. The lower back, rump, upper tail covets, and rectrices are dark brown. The upper wing coverts are also dark brown and edged with argus brown and can be spotted with fine white specks. Remiges are light brown.

Juvenile: Cap and body dark brown, with the upper back and back of neck light brown. Face and throat are slightly grayish. Lower back, rump, and tail are black. Outer surface of wings are very dark brown (almost black). No white spots present on juveniles.

Molts

There are no published data on the annual timing of molt in Galapagos Rail. However, a closely related species, Black Rail (Laterallus jamaicensis), undergoes a partial prealternate molt between mid-March to mid-May and and a complete prebasic molt from August to October, following breeding (Eddleman et al. 1994).

Bare Parts

Iris: red

Bill: dark brown

Tarsi and toes: dark brown

Bare parts color data from Ridgway and Friedmann (1941).

Measurements

Body Part

 

n

 

Length (mean, mm)

Reference

Adult Male

 

 

 

Wing

 

16

 

66.4

Ridgway and Friedmann 1941

Tail

 

16

 

24.6

Ridgway and Friedmann 1941

Tarsal Length

 

16

 

22.7

Ridgway and Friedmann 1941

Tarsal Length

 

26

 

12

Franklin et al. 1979

Culmen

 

16

 

15.6

Ridgway and Friedmann 1941

Culmen

 

29

 

4.5

Franklin et al. 1979

Middle Toe (without claw)

 

16

 

24.3

Ridgway and Friedmann 1941

Middle Toe (with claw)

 

29

 

21

Franklin et al. 1979

Adult Female

 

 

 

Wing

 

21

 

66.3

Ridgway and Friedmann 1941

Tail

 

21

 

24.5

Ridgway and Friedmann 1941

Culmen

 

21

 

14.9

Ridgway and Friedmann 1941

Tarsus

 

21

 

21.9

Ridgway and Friedmann 1941

Middle Toe (without claw)

 

21

 

23.5

Ridgway and Friedmann 1941

Mass: ca 35-45 g (Franklin et al. 1979)

Recommended Citation

Hill, E. (2013). Galapagos Rail (Laterallus spilonota), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.galrai1.01