The Spruce Grouse or Canada Grouse (Falcipennis canadensis) is a medium-sized grouse

Grouse

Grouse are a group of birds from the order Galliformes. They are sometimes considered a family Tetraonidae, though the American Ornithologists' Union and many others include grouse as a subfamily Tetraoninae in the family Phasianidae...

 closely associated with the coniferous boreal forests or taiga

Taiga

Taiga , also known as the boreal forest, is a biome characterized by coniferous forests.Taiga is the world's largest terrestrial biome. In North America it covers most of inland Canada and Alaska as well as parts of the extreme northern continental United States and is known as the Northwoods...

 of North America. It is one of the most arboreal grouse, fairly well adapted to perching and moving about in trees. When approached by a predator, it relies on camouflage and immobility to an amazing degree, for example letting people come to within a few feet before finally taking flight, a behavior that has earned it the moniker "fool hen". It is present in Quebec and its French name is "Tétras du Canada".

Description

Spruce Grouse are 38-43 cm long (15-17 inches); males weigh 550-650 g (19-23 ounces) and females 450-550 g (16-19 ounces). 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. 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

Ruffed Grouse

The Ruffed Grouse is a medium-sized grouse occurring in forests from the Appalachian Mountains across Canada to Alaska. It is non-migratory.The Ruffed Grouse is frequently referred to as a "partridge"...

 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 like ruffed grouse do.

Taxonomy and systematics

In the first half of the century, Spruce Grouse were classified as two separate species in the genus Canachites: Spruce Grouse (C. canadensis) and Franklin's Grouse (C. franklinii). Then the species were unified and moved to the genus Dendragapus, congeneric with the Blue Grouse

Blue Grouse

The genus Dendragapus, contains two closely related species of grouse that have often been treated as a single variable taxon . The two species are the Dusky Grouse and the Sooty 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 is now recognized as belonging to the genus Falcipennis. Currently six subspecies are recognized:

F. c. osgoodi: Central Alaska and Northwest Territories of Canada.

F. c. atratus: Coastal Southwestern Alaska.

F. c. canadensis: Canada from Central Alberta to Labrador, introduced in Newfoundland in 1964 and Anticosti Island in 1985-86.

F. c. canace: Maine, Southern Canada from Manitoba to Nova Scotia.

F. c. torridus: Nova Scotia.

F. c. franklinii: British Columbia and Rocky Mountains.

Distribution and habitat

As a specialist of the taiga, the Spruce Grouse is found throughout Canada. In the United States it is present in Alaska, Maine, northern Michigan, northeastern Minnesota, and the mountane coniferous forests of Montana, Idaho, and Washington.

Spruce Grouse are always associated with conifer-dominated forests, be it pine, spruce, or fir. They seem to prefer young successional

Ecological succession

Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...

 stands. In summer they can be found near rich understory of blueberries and other shrub, and in winter they prefer denser stands.

Food

The staple food is conifer needles, clipped directly from the tree, preferably the midcrown of pines though other conifers are exploited as well. In summer the birds can also forage on the ground, eating berries

Berry

The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....

, green plants, fungi, and some insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s. In winter, when only needles are consumed, the caeca (dead-end extensions of the intestines) increase in size to support digestion. The crop

Crop (anatomy)

A crop is a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion that is found in many animals, including gastropods, earthworms, leeches, insects, birds, and even some dinosaurs.- Bees :Cropping is used by bees to temporarily store nectar of flowers...

 is also well developed: up to 45 cc of needles (about 10 % of body mass) can be stored in the crop at the end of the day, to be digested over the duration of the night fast. Like other birds, spruce grouse consume grit or small stones to help their gizzard

Gizzard

The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ found in the digestive tract of some animals, including birds, reptiles, earthworms and some fish. This specialized stomach constructed of thick, muscular walls is used for grinding up food; often rocks are...

 break down food. Chicks under 1-week old feed on insects and other arthropods

Arthropod

An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...

, then switch to berries and fungi until the fall, when they start feeding on needles.

Reproduction

Males are promiscuous; they disperse and advertise a territory that is visited by females for mating. Females are solely responsible for the rest of the reproductive effort. For a nest, they scratch a depression in the ground in a bush or under a low-lying coniferous branch or fallen tree, away from other females and from the males' territories. The nest is lined with grasses, leaves, and a few feathers. Nesting season is from early May to early July. Up to 10 eggs may be laid, the usual number being 4-7. Laying rate is 1 egg every 1.4 days. Eggs are about 40 mm in length (1.5 inches) and are tawny olive or buff, marked with blotches of brown. Incubation begins with the last egg laid and lasts about 24 days. Young are about 15 g at hatching (0.5 ounces) and they are precocial

Precocial

In biology, the term precocial refers to species in which the young are relatively mature and mobile from the moment of birth or hatching. The opposite developmental strategy is called "altricial," where the young are born or hatched helpless. Extremely precocial species may be called...

; they walk out of the nest as soon as they are dry (about 8 h after hatching). They are capable of fluttering up from the ground at 1 week of age. The brood stays together and is accompanied by the hen, who broods them all night and frequently during the day until the young are 3-5 weeks old. Brooding behaviour of the female seems to be initiated by specific calls from the chicks when they are cold. At 70-100 days of age, chicks tend to leave the group and become independent.
Females breed only once a year. Most females first breed at 1 year of age, but about half the males delay establishing a territory until 2 years. The species' lifespan appears to be about 5-6 years in the wild, though one study in Southwestern Alberta has found two males and one female that lived to be at least 13 years old.

Sounds

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.

Locomotion

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.

Movement

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).

Predators

Spruce Grouse eggs are taken by red squirrels, foxes, weasels, and probably corvids. Adults can fall prey to various hawks and owls, foxes, and coyotes.

Relationship with humans

This species is commonly hunted. Annual bag figures in the late 1970s were about 188,000 birds in the USA and about 360,000 in Canada. Even though it has been deemed Of Least Concern by IUCN, in the United States this bird is a protected species according to many northern states' hunting rules.

External links

• Spruce Grouse Factsheet New York Department of Environmental Conservation
• Spruce Grouse, Cornell Lab of Ornithology