Tétras du Canada

Identification

Spruce grouse are 38–43 cm (15–17 in) long; males weigh 550–650 g (19–23 oz) and females 450–550 g (16–19 oz). The spruce grouse has a wingspan range of 21.5-22.6 in (54.5-57.5 cm). Races vary slightly in plumage, especially in the tail pattern and in the extent of white on the underparts, but in general adult males are mainly grey above and black below, with white spots along the side, and a red patch of bare skin over the eye called the "eyebrow comb". This red eyebrow comb, should not be confused by a similar yellow marking found on other species of grouse including, but not limited to, sharp-tailed and dusky grouse. Adult females are mottled brown (red morph) or mottled grey (grey morph) with dark and white bars on the underparts. Juveniles resemble females. Females may be confused with ruffed grouse but they have a dark tail with a pale band at the end (while the reverse is true in ruffed grouse) and they do not erect their crown feathers when alarmed the way ruffed grouse do.<p>Spruce grouse are among the most silent of all grouse, but they nevertheless have a number of calls used to warn of predators, to repel territorial intruders, to maintain brood cohesion, or to elicit brooding. In the subspecies franklinii, territorial males are notable for their wing-clap display. At the end of a short flight through the trees, the wings are brought together over the back so as to produce two sharp claps, about 0.5 s apart, loud enough to be heard by the human ear 150 m away. These territorial displays can sometimes be elicited by similar hand clapping, and can be used to detect male territories and estimate their density. Other non-vocal sounds include soft drumming by territorial males (a sound produced by the beating wings) and a tail-swish and a whoosh produced by the tail feathers in flight.

Taxonomie

In 1747, the English naturalist George Edwards included an illustration and a description of a female spruce grouse in the second volume of his A Natural History of Uncommon Birds. He used the English name "The Brown and Spotted Heathcock". Edwards based his hand-coloured etching on a preserved specimen that had been sent to him in London from the Hudson Bay in Canada by a Mr Light. Edwards was later sent what he assumed was a specimen of the male bird by James Isham. In 1750, he included the male bird in the third volume of his book under the English name "The Black and Spotted Heathcock". When in 1758, the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he placed the spruce grouse with other grouse in the genus Tetrao. Linnaeus included a brief description, coined the binomial name Tetrao canadensis and cited Edwards' work. The spruce grouse is now the only species placed in the genus Canachites that was introduced in 1885 by the zoologist Leonhard Stejneger. The genus name Canachites combines the name Canace from Greek mythology with the Ancient Greek -itēs meaning "resembling".<p>In the first half of the 20th century, spruce grouse were classified as two separate species in the genus Canachites: spruce grouse (C. canadensis) and Franklin's grouse (C. franklinii), a position reinstated by Birdlife International in 2014. However, as of early 2021, the International Ornithological Congress (IOC), the American Ornithological Society, and the Clements taxonomy retain Franklin's grouse as a subspecies of spruce grouse.<p>The species was later moved to the genus Dendragapus, congeneric with the blue grouse with which spruce grouse often share coniferous habitats. However, spruce grouse do not have inflatable cervical sacs as in blue grouse, and the natal plumage of the two species is different. Based on its stronger resemblance to the Siberian grouse (Falcipennis falcipennis), the spruce grouse was later reclassified into the genus Falcipennis. However, taxonomic studies found this classification to be paraphyletic, with the Siberian grouse being basal to a clade containing the spruce grouse, Tetrao, and Lyrurus. Due to this, the spruce grouse was again reclassified in Canachites, bringing its taxonomy full-circle.<p>The spruce grouse has six recognized subspecies:

Nom scientifique

Canachites canadensis

Autorité

(Linnaeus, 1758)

Ordre

Galliformes

Famille

Phasianidae

Genre

Canachites

Répartition et habitat

As a specialist of the taiga, the spruce grouse is found throughout Canada. In the United States, it is present in Alaska, northern New England, the Adirondacks in New York, northern Michigan, northeastern Minnesota, northern Wisconsin and the montane coniferous forests of Montana, Idaho, Maine, Oregon, and Washington. Spruce grouse are always associated with conifer-dominated forests, be they pine, spruce, or fir. They seem to prefer young successional stands. In summer they can be found near rich understory of blueberries and other shrub, and in winter they prefer denser stands.<p>The spruce grouse is essentially a permanent resident. However, in southwestern Alberta up to 35% of females and 7% of males move several kilometers (up to 11) between summer breeding sites and wintering sites. Similar movements have also been documented in Alaska and New Brunswick (Canada).

Migration

Resident species

Comportement

This species prefers to walk on the ground or along tree limbs rather than fly. Like other grouse, in the fall they grow "snow shoes" (short lateral extensions, or pectinations) on their toes. This increases the surface area of the toes and helps support the bird on snow and probably to grip branches as well. The pectinations are shed in the spring.Flights are usually over short distances, most commonly from the ground to a tree nearby, or vice versa. Flight can be rapid but no actual measures of velocity have been made.

Conservation

Tendance de la population

stable