Greater Sage Grouse

Greater Sage Grouse

Sage grouse

Kingdom
Phylum
Class
Order
Family
Genus
SPECIES
Centrocercus urophasianus
Population size
150,000
Life Span
10 yrs
TOP SPEED
78 km/h
WEIGHT
1-3 kg
HEIGHT
60 cm
LENGTH
52-76 cm

The Greater sage grouse is the largest grouse species in North America. This bird is sexually dimorphic. Male grouse have yellow lores and patches on the back of their neck. The top of their head is grey in color. They also possess brown and buff colored upper chest, while their middle chest consists of a large white collar, hiding esophageal sacs which inflate at the courtship period. In addition, they have a notable black marking on their abdomen. Males have long tail feathers, which are tapered in shape. On the other hand, feathering of the female grouse is more cryptic, allowing them to use it as a perfect camouflage during nesting period. Their plumage is covered with gray and brown, having lower degree of white coloring, compared to males. Typically, females have gray and white colored throat. They do not possess those espophageal sacs, and their tail is somewhat shorter than that of males.

Distibution

These birds are distributed across North America with their range, stretching from southern Alberta and Saskatchewan in Canada to the western United States. Their preferred habitat is sagebrush of medium-density, combined with other plants. The Greater sage grouse occur mainly in shrub-steppe and meadow-steppe areas as well as hilly terrains, adjacent to valleys.

Greater Sage Grouse habitat map

Geography

Continents

Climate zones

Habits and Lifestyle

Greater sage grouse are quite social animals, gathering in flock, consisted of hundreds of birds. The sage grouse are diurnal birds. They are efficient in flying short distances and are not fast runners, though preferring to move around primarily by walking. When facing danger, the sage grouse will usually escape, hiding or flying. The breeding season starts in spring, when the birds congregate in leks, looking for mates. They gather on the breeding ground to perform courtship rituals. During the display, they unfold the strut surrounding their tail, filling and emptying their esophageal sacs with a loud booming sound, heard at a distance of a mile. In Washington, the sage grouse populations live in the sagebrush country, generally remaining within the same areathroughout the year, except for winter months, when they move to lowlands.

Diet and Nutrition

Great sage grouse are predominantly herbivorous.Typically, these birds forage on the ground, consuming buds and flowers of different plants. Their usual winter diet primarily consists of sagebrush leaves, while, during the summer, the sage grouse, and especially their young, will feed upon a wide variety of insects.

Mating Habits

MATING BEHAVIOR
REPRODUCTION SEASON
during the spring
INCUBATION PERIOD
25-27 days
INDEPENDENT AGE
10-12 weeks
BABY NAME
chick
BABY CARRYING
7-9 eggs

They have polygynous mating system, where one male mates with a number of females. During the breeding season, which takes place in spring, males perform courtship rituals in special areas called "leks", where the female constructs the nest after mating. She typically uses grass and forbs under the sagebrush as nesting materials and cover. And when the nest is built, she lays 7-9 eggs, incubating them for 25-27 days. The Greater sage grouse rear one breed in each season. The hatchlings start flying at the age of 2-3 weeks and at 5-6 weeks old they become strong flyers. Then, after first molting, at the age of 10 to 12 weeks, young become relatively independent.

Population

Population threats

The major concerns are degradation, fragmentation and loss of their natural habitat. Large areas with sagebrush communities currently turn to croplands and pastures. In croplands, these birds are threatened by herbicides and invasion of exotic plant species, which brings to unnatural fires. In pastures, excessive livestock grazing leads to reduction of their population within their home range.

Population number

The overall estimated population of the Greater sage grouse is about 150,000 mature birds. On the IUCN Red List, the species is classified as Near Threatened (NT) with decreasing number of population.

Ecological niche

The Greater sage grouse help maintain local sagebrush communities healthy, thus aiding other species of their habitat, such as songbirds or pronghorn.

Fun Facts for Kids

  • During the winter, the birds prepare for the approaching breeding season, gaining weight and strength by eating sagebrush leaves and getting required moisture from the snow.
  • During the courtship displays, males usually stand to the side of the female, not in front of her. The reason of this is that the booming call they emit, sounds louder off to the sides, than straight ahead.
  • As common among grouse species, males of the sage grouse do not participate in rearing the chicks.
  • Greater sage grouse typically use the same lekking grounds for many years.
  • Their stomach is capable of digesting tough sagebrush, upon which they primarily feed.
  • Before performing the courtship display, males fill the pouch of their esophagus with air, hold it for a while and then squeeze it with force, thus beginning the display.

References

1. Greater Sage Grouse Wikipedia article - https://en.wikipedia.org/wiki/Greater_sage-grouse
2. Greater Sage Grouse on The IUCN Red List site - http://www.iucnredlist.org/details/22679503/0

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