Both the dusky grouse and the spruce grouse are medium-sized grouse species found in North America. They occupy similar habitats and have some overlapping ranges, which can cause confusion between the two. However, there are several key differences in appearance, behavior, habitat preferences, and distribution that set them apart.
Quick Facts
| Characteristic | Dusky Grouse | Spruce Grouse |
|---|---|---|
| Scientific Name | Dendragapus obscurus | Falcipennis canadensis |
| Other Common Names | Blue Grouse | Franklin’s Grouse, Fool Hen |
| Adult Size | 16-20 inches long | 15-17 inches long |
| Plumage | Males are grayish blue with a long tail. Females are mottled brown. | Males are gray with a reddish colored tail. Females are mottled brown. |
| Distinguishing Mark | White patches above eyes | Dark band at end of short tail |
| Habitat | Coniferous forests, mountain shrublands | Boreal forests, muskegs |
| Range | Western North America | Canada, Alaska, Northern U.S. |
| Conservation Status | Least Concern | Least Concern |
Appearance
The most noticeable difference between dusky and spruce grouse is in the male’s appearance during breeding season.
Male dusky grouse have grayish-blue plumage over most of their body, with a long square tail and red combs over their eyes. Their most distinctive feature is the white patches of feathers above their eyes.
Male spruce grouse are more modestly colored, with grayish-brown plumage and a much shorter tail. They lack the white eye patches of duskies. Instead, spruce grouse can be identified by the distinct dark band at the tip of their tails.
Females
Females of the two species are quite similar. They have mottled brown and black plumage that provides camouflage on the forest floor.Female dusky grouse may be slightly more gray compared to the reddish-brown female spruce grouse. But in general, positive identification requires looking at range or the male’s appearance.
Juveniles
Young grouse look much like females until they acquire adult plumage at around 5-6 months of age. Juvenile duskies have more distinct barring on their underparts compared to spruce grouse.
Behavior
The behavior of dusky and spruce grouse also differs in ways that can help distinguish them.
Dusky grouse are known for the loud, resonant hooting sounds males make to attract females in spring. Groups of male duskies will gather together to perform communal displays. Females visit these lek sites to select a mate.
Spruce grouse males are much less conspicuous during the breeding season. They do not form large displaying groups. Instead, they make softer hooting and clicking sounds to attract females in more solitary courting displays.
Dusky grouse spend more time perched in trees and fly frequently to reach food sources or escape predators. Spruce grouse prefer to walk and spend most of their time on the ground. When approached, spruce grouse are more likely to rely on camouflage rather than taking flight.
Habitat
The habitats preferred by dusky and spruce grouse differ in ways that reflect their behavior:
Dusky grouse thrive in more open, drier coniferous forests and mountain shrublands. They require a mix of forest and more open understory for feeding and display sites.
Spruce grouse are specialized for dense, wet boreal forests with minimal undergrowth. They occur in mature stands of spruce, fir, pine, and larch. Spruce grouse also use muskegs and thrive around bogs.
Duskies avoid the wettest, most dense boreal forests preferred by spruce grouse. The differences in habitat allow the two species to occupy overlapping ranges without competing.
Range and Distribution
Dusky and spruce grouse have adjacent but distinct distributions across North America:
Dusky grouse occur along the Pacific Coast and Rocky Mountains from southern Alaska through the western United States. They are found in the major mountain ranges of the West and into New Mexico and Colorado.
Spruce grouse range throughout Canada from the treeline south through the boreal forests. They occur in Alaska and across northern parts of the continental United States from Washington to the New England area.
There is a zone of overlap along the Cascades, British Columbia, Alberta, and western Montana where both dusky and spruce grouse occur. Their habitat preferences minimize competition in these overlapping areas.
Conservation Status
Neither dusky nor spruce grouse are considered threatened species. Both are classified as Least Concern by the IUCN Red List:
Dusky grouse remain common throughout their range. Habitat loss is not currently a major threat.
Spruce grouse numbers are declining in parts of their range, primarily due to habitat loss. But across their widespread range, populations remain steady enough to be considered stable.
Hunting of both species is permitted with appropriate regulation. Maintaining habitats that provide the mix of forest cover and openings preferred by the two grouse will be important for their long-term conservation.
Conclusion
In summary, dusky and spruce grouse can be differentiated by several key traits:
– Male breeding plumage – duskies have prominent white eye patches, spruce have conspicuous tail banding.
– Behavior – duskies are more social, spruce are more solitary.
– Habitat – duskies prefer open conifer forest, spruce require dense boreal forest.
– Range – overlap occurs but center of abundance is distinct for each species.
Both are currently common gamebirds that thrive in well-managed forest habitats. Conserving large tracts of their preferred forests across North America will ensure healthy populations into the future. With attention to details of appearance, call, habitat preference, and geography, experienced birders can confidently distinguish between the dusky grouse and spruce grouse.
