THE PRAIRIE GROUSE
North American distribution of Pinnated Grouse (Greater and Lesser Prairie-Chickens) once ranged from the Gulf Coast to Southern Canada, and from the Atlantic Seaboard to the Rocky Mountains, but this range has been steadily decreasing over the centuries. Of the three subspecies of Greater Prairie-Chickens, the Heath Hen is extinct, and the Attwater's Prairie-Chicken on the TX coast is hovering on the brink of extinction. The bulk of Greater Prairie-Chickens are today found in tall grass and mixed grass prairie regions of KS, NE, and SD with fringe and remnant populations extending into other states and provinces such as OK, MO, ND, and Ontario.
In other states such as WI, IL, MI, and MN, populations continue to exist through reintroduction efforts. On the fringe of the distribution such as in OK, numbers have gradually decreased to a low in the mid 90's, but have shown gradual increases during the last three years. While Greater Prairie-Chicken numbers appear stable in some states comprising the heart of the distribution region, the latest counts indicate that today there are only about one-third as many of this species as there were just 30 years ago. (Source: Ron Westermeier and Sharon Gough, Illinois Natural History Survey and Missouri Department of Conservation respectively, 1999 Report on the National Outlook and Conservation Needs for Greater Prairie-Chickens).
The greater prairie-chicken has one subspecies that is extinct in its original range in the northeastern U.S. (heath hen) and another that is close to extinction in southern Texas (Attwater’s prairie-chicken). The third subspecies is largely found in acquired range since most of its original range in the mid-western U.S. has been converted from prairie to cropland.
The lesser prairie-chicken is still found in its native range of sand sagebrush and shinnery oak prairie in Texas, New Mexico, Oklahoma, Kansas, and Colorado, but its range has been greatly reduced and fragmented. As a consequence, it is a candidate for federal listing under the Endangered Species Act.
General Description: Medium-sized grouse weighing 700-800 g. Total length 38-41 cm. Sexes and plumages similar throughout year. In adults, plumage is uniformly barred with alternating brown and buffy white bands. Upperparts are darker and more richly colored than underparts. Chin and throat largely unmarked. Tail short, rounded and brownish black. Males display conspicuous yellow eye-combs and dull red gular sacs during courtship. Males also have elongated pinnae on each side of the neck, which are held erect during courtship display. Females have shorter pinnae. Immatures similar to adults, but more richly colored, especially on throat. Total length, and lengths of wing-chord, pinnae, and tail, greater in males than females, and within each sex tend to be greater in adults than in yearlings.
General Food Types: Diet consists of insects, seeds, leaves, buds, and cultivated grain crops. Juveniles <10 weeks old feed primarily on insects, principally grasshoppers (Orthoptera) and beetles.
Daily Routine: Fall/Winter: Birds assemble into mixed flocks feeding primarily in shinnery oak-grasslands, but may also feed on waste grains. Spring/Summer: During breeding season, males congregate on traditional lek sites to attract females to mate. Nests are initiated mid-April through late May, typically within 2 weeks of lek attendance and copulation. Hatching peaks late May-mid June throughout range. Re-nests (if initial clutch is lost) initiated mid-May-early June, with hatching mid-June-early July. Estimates of average clutch size range from 10-12 eggs. Eggs typically ovate, averaging 42.01 (range 40.40-43.93) x 31.60 mm (range 29.17-33.15, n = 86). Egg color varies from cream to ivory yellow, sometimes dotted with pale brown or olive spots. Chicks are precocial and nidifugous, leaving nest with hen within 24 hours of hatching. Chicks capable of short flights at 2 weeks of age. Loss of brood integrity occurs at 12-15 weeks, coinciding with fall dispersal.
Primary Predators: Predators of adults and chicks include Rough-legged Hawk (Buteo lagopus), Red-tailed Hawk (Buteo jamaicensis), Prairie Falcon (Falco mexicanus), Cooper's Hawk (Accipiter cooperii), Northern Harrier (Circus cyaneus), Ferruginous Hawk (Buteo regalis), Golden Eagle (Aquila chrysaetos), Great Horned Owl (Bubo virginianus), coyote (Canis latrans), and badger (Taxidea taxus). Nest predators include Chihuahuan Raven (Corvus cryptoleucus), coyote, badger, striped skunk (Mephitis mephitis), ground squirrel (Spermophilus spilosoma), and bull snake (Pituophis melanoleucus).
Primary Problems: Population declines since 1800s have resulted from conversion, degradation, and fragmentation of habitat through extrinsic factors, including drought, conversion of rangeland to cropland, overgrazing by domestic livestock, chemical control of sand sagebrush and shinnery oak on rangelands, and energy development.
The sharp-tailed grouse was originally found in shrub-dominated prairies and bogs throughout much of North America. However the original range has been substantially reduced in southern portions of the range, particularly in the sagebrush habitats of the west. The Columbian subspecies has been petitioned for federal listing under the Endangered Species Act.