E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Coturnicops noveboracensis Gmelin
Yellow Rail
Family: Rallidae

Species account author: Jamie Fenneman

© Greg Lavaty  Email the photographer   (Photo ID #9184)


Distribution of Coturnicops noveboracensis in British Columbia.
(Click on the map to view a larger version.)
Source: Distribution map provided by Jamie Fenneman for E-Fauna BC

Species Information

Adult
The upperparts are blackish to dark blackish-brown with fine white feather edges, which create a scaled appearance, and extensive, broad yellowish-buff streaks on the back, scapulars, and rump. The upperwing coverts are mottled with dark brown and yellow-buff and are finely scaled with white. The primaries are dark grey and the secondaries are largely white, forming a bold white wing patch that is visible in flight. The very short tail is black with several narrow white bands on the tail feathers. The breast and upper belly are largely yellowish-buff, contrasting with the white-barred blackish or dark brown flanks, lower belly, and undertail coverts. The underwings are largely white. The head is largely yellowish-buff, with brown mottling and scalloping on the nape, hindneck, and sides of the neck, and blackish or blackish-brown crown, and a blackish-brown patch on the lores and ear coverts that creates a dark ‘mask or smudge through the eye. The iris is dark, the relatively short, stout bill is yellowish, and the legs and feet are flesh-pink to greenish or greyish.

Immature
This plumage is held from late summer (August) throughout the fall and winter of the first year, and is lost in late winter prior to spring migration. It is somewhat similar to the adult, but the head, neck, sides of the breast, and upperparts are extensively and boldly speckled with white. The bill is largely brownish, often with some pale yellowish at the base, and is thus darker than that of the adult.

Measurements
Total Length: 16-19 cm
Mass: 41-68 g

Source: Bookhout (1995); Sibley (2000)

Biology

Identification

Very few individuals have been observed in B.C., and the vast majority of records pertain to singing males which produce a very unique and distinctive song. When observed, this species is likely to be mistaken only for juvenal-plumaged Sora, and several previously-cited records have apparently been the product of such a misidentification. Juvenile Sora has extensive buff on the face and breast, which is responsible for the confusion with similarly-plumaged Yellow Rail. If seen in flight, such as an individual flushed from marshy vegetation, the large white patch on the secondaries of the Yellow Rail should immediately serve to distinguish it from a juvenile Sora (but beware of the narrow white trailing edge to the secondaries of juvenile Sora, which may cause some confusion with the white secondary patch of Yellow Rail). The buff-striped upperparts of Yellow Rail are also diagnostic (upperparts of Sora are brown and finely speckled with white). Yellow Rail is a noticeably smaller species and is exceedingly secretive and extremely unlikely to be observed in the open (except for a bird that is flushed from under foot and flies a short distance before dropping back into cover). The Sora, in contrast, is much bolder and regularly ventures into the open, sometimes even swimming in open water. Finally, Yellow Rail is closely associated with wet meadows and sedge marshes, whereas Sora is commonly encountered in a wide variety of marshy habitats (including cattail marshes, tule stands, etc.); thus, any potential Yellow Rail outside of the very narrow habitat range of the species is more likely to be a juvenile Sora and should be identified with caution.
Vocalizations

The male’s song is a unique and very distinctive series of dry, mechanical clicks in a consistent pattern of two clicks followed by a more rapid series of three clicks: tic, tic, tictictic…..tic, tic, tictictic…..tic, tic, tictictic…. This song is repeated for long periods of time without pause, and is most frequently given throughout the night (although it is also given during the day, particularly in the early morning). It is very reminiscent of the sound made by tapping two small stones together. Other calls that are heard less frequently include a descending cackle of about 10 notes, a series of three or four clunking notes that sound like distant knocking on door, quiet croaking notes, and soft wheezing or clucking notes.

Source: Bookhout (1995); Sibley (2000)

Breeding Ecology

Courtship
The mechanism of pair formation of this species is poorly known, but appears to largely involve the male’s song as a means of courtship display. It is likely monogamous throughout the breeding season, although serial monogamy has been reported from captive birds.

Nest
The nest is constructed ~1 month before the eggs are laid, and is therefore likely built during June in B.C. Both sexes participate in the nest-building process (although the female contributes more effort, particularly in the latter stages), and sometimes a second nest is built but is used only for brooding the young. The nest is placed on the ground or up to 15 cm high (sometimes above shallow water) and is woven into the surrounding stems of sedges and grasses; it is usually situated beneath overhanging dead vegetation for concealment. The nest itself is a small, thick, rather deep cup 7-10 cm wide and 3-8 cm deep. It is composed of the stems and leaves of sedges and grasses that are gathered from the vicinity of the nest site.

Eggs
A clutch of (5) 8 (10) eggs are laid after the completion of the nest (likely in late June or early July in B.C.) and are incubated by the female for 13-18 days before hatching. The smooth, non-glossy eggs are creamy-buff and are sparsely to heavily speckled around the larger end with reddish-brown spots. Although eggs have not been recorded in B.C., they are likely present in the province between late June and mid-July.

Young
The young are semi-precocial upon hatching and are completely covered in long, glossy black down (sometimes with a faint greenish cast on the head and a dull brownish cast on the body); the bill is bright pink when first hatched, but gradually becomes whitish. The young are able to stand and walk within a day of hatching, and by the second day they leave the nest to forage alongside the female. They continue to be fed by the female for 5 days after leaving the nest, but subsequently acquire all food on their own. They are brooded by the female for ~3 weeks after they leave the nest, often retiring to a special ‘brood nest’ for brooding. The young are able to fly weakly at ~35 days of age, after which time they become independent. Although they have never been documented in the province, dependent young are likely present in B.C. between early July and early to mid-August.

Source: Bookhout (1995); Baicich and Harrison (1997)
Foraging Ecology

This species forages almost exclusively within very dense vegetation (usually sedges) and spends almost all of its time concealed; thus its foraging habits are poorly known. It feeds primarily on aquatic and semi-aquatic invertebrates, with small freshwater snails forming the bulk of its diet; other prey species include insects and their larvae, earthworms, and spiders. It also consumes the seeds of sedges and other aquatic plants, especially outside of the breeding season. It picks its prey from the surface of the mud, from low vegetation, and from the surface of the water or even from 3-4 cm below the surface of the water.

Source: Bookhout (1995)

Habitat


The Yellow Rail is found in a very particular and unique habitat throughout its range. It occurs in open, wet meadows with extensive cover of sedges (and sometimes aquatic grasses) and either a permanently moist substrate or shallow standing water (<15 cm deep). The habitat is generally dominated by vast swaths of aquatic sedges with woody vegetation limited to occasional emergent willow shrubs or other low, scattered shrubs. It is rarely encountered in cattail stands. Due to the annual water level fluctuations in this type of habitat, areas may be suitable for Yellow Rail breeding only in wetter years and may be completely unsuitable during drier years (during which time the rails are often completely absent from the sites).

Source: Bookhout (1995)

Distribution

Global Range

Breeds locally across the boreal forests of North America, from northeastern B.C., northern Alberta, and the southern Northwest Territories east to southern Quebec and New Brunswick, occurring south as far as North Dakota, northern Minnesota, northern Wisconsin, and northern Michigan. A small and isolated population also breeds in southern Oregon. It winters along the southern Atlantic and Gulf coasts of the southeastern United States, from North Carolina to southern Texas.
BC Distribution

Breeding
Rare and local, but annual, in the Peace River lowlands of northeastern B.C., occurring west at least as far as the Chetwynd area, north to Boundary Lake, and south at least as far as Swan Lake and the Tupper area. It is casual during the breeding season (June-July) in eastern B.C. west of the Rocky Mountains (Yoho National Park, Lake Windermere area) and, although there are only a few records for this area, this species is very easily overlooked if it occurs in low numbers and it is highly possible that occasional individuals are breeding within this region of the province as well. Recently (2010), territorial males were documented from a single site in the Anahim Lake area of the central interior, representing the first documentation of birds during the breeding season in B.C. outside of the Peace River region. There has been no definitive confirmation of breeding anywhere in the province, but the annual occurrence of multiple territorial males at several different locations in the Peace River area and the recent detections of multiple territorial males in the Chilcotin region suggest a small but persistent breeding population does indeed occur.

Migration and Vagrancy
Spring migrants appear late in B.C., with the earliest individuals appearing in early June (rarely in late May). Individuals appear directly on breeding territories, presumably entering the province from Alberta. Virtually all records of this species are from the breeding grounds in June and July, and the species becomes more or less invisible once the male ceases calling in mid- to late July. There are no definitive records in B.C. after late July, although it presumably migrates out of the province during August. The single record of a fall migrant, from the Valmount area (west of the Rocky Mountains) in late August, is not universally accepted and may pertain to a mis-identified juvenile Sora.

Source: Campbell et al. (1990b)

Conservation

Population and Conservation Status

The first record of Yellow Rail in B.C. is from the Kootenay area of B.C. in 1964, but this species has only been recognized as occurring in the province since 1989 when it was detected in the Peace River region. Several records occurred during the early 1990s, but it was not until the late 1990s that this species began to be detected regularly in the Peace River area, first appearing near Chetwynd but subsequently being detected at several sites east to the Alberta border. In 2002, a population of several territorial males was discovered in the Del Rio area northeast of Chetwynd, and the species has appeared at this site annually since then, with up to 3 singing males detected at a time. Although nests or young have never been observed, it is now clear that this species is breeding in B.C. It is known to be difficult to detect, even where it occurs in numbers, and is almost always detected by hearing the song of the male (very few individuals have actually been visually observed in B.C.). Although it has appeared only recently in the province, it is unclear whether this population has always occurred in B.C. but has been overlooked or whether it is a new arrival from populations in adjacent areas of Alberta. Because of its apparent rarity in B.C., it is recognized as red-listed (endangered) in the province by the B.C. Conservation Data Centre (CDC). It is also rather sparsely distributed throughout its range in Canada (which encompasses the vast majority of the species’ entire global range), and is susceptible to habitat degradation and loss of wetlands, and thus is recognized as a federal species of “Special Concern” by COSEWIC (Committee on the Status of Endangered Wildlife in Canada).

Source: Campbell et al. (1990b)

Taxonomy


Although there are two subspecies of Yellow Rail that have been described, all extant populations are referable to the nominate C.n.noveboracensis. The other subspecies, C.n.goldmani, formerly occurred in central Mexico but appears to have become extinct in the past century due to habitat destruction. This species is very closely related to the similar Swinhoe’s Rail (Coturnicops exquisita) of eastern Asia, and the two species are sometimes considered conspecific by some authors.

Source: Bookhout (1995)

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
NativeS2BRedSC (Nov 2009)
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Range and Status Information Links

Additional Photo Sources

General References


Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2017. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 25/06/2019 10:41:55 PM]
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