The greater prairie chicken and the lesser prairie chicken are two closely related species of grouse found in the prairies of North America. Both species have experienced significant population declines over the past century due to habitat loss and are now considered vulnerable. However, there are several key differences between these two birds in terms of appearance, behavior, habitat preferences, and conservation status.
Taxonomy and Evolution
The greater prairie chicken (Tympanuchus cupido) and the lesser prairie chicken (Tympanuchus pallidicinctus) both belong to the order Galliformes, family Phasianidae, and genus Tympanuchus. They are considered “true prairie grouse” along with the sharp-tailed grouse. It is believed that the two prairie chicken species diverged from a common ancestor during the Pleistocene epoch. The lesser prairie chicken is thought to have become a distinct species more recently, around 8,000-10,000 years ago after the last glacial period.
Appearance and Size
The most noticeable difference between the greater and lesser prairie chickens is their appearance.
The greater prairie chicken is a medium to large bird measuring 16-18 inches long with a rounded tail and small head. Males weigh between 1.5-2.5 pounds while females weigh 1-1.75 pounds. They have feathered feet and cryptically colored plumage to help them blend into the prairie habitat. Their main body feathers are barred with alternating brown and buff coloration. Around the neck, they have conspicuous orange-yellow air sacs called tympanums that can inflate to the size of an orange. During their mating display, males will inflate these air sacs and produce a distinct booming vocalization. Females lack the prominent tympanums and are overall pale brown in coloration with neat barring.
The lesser prairie chicken is slightly smaller at 14-16 inches long. Males weigh an average of 1.25-1.75 pounds while females weigh 0.9-1.25 pounds. They have less distinct barring and are overall paler in coloration. The lesser has smaller yellow tympanic air sacs that are less bright than the greater prairie chicken. Their feet are less feathered as well. Females are very difficult to distinguish from males.
Characteristic | Greater Prairie Chicken | Lesser Prairie Chicken |
---|---|---|
Length | 16-18 inches | 14-16 inches |
Male Weight | 1.5-2.5 lbs | 1.25-1.75 lbs |
Female Weight | 1-1.75 lbs | 0.9-1.25 lbs |
Plumage Color | Prominent brown and buff barring | Paler, less distinct barring |
Tympanum | Large, bright orange-yellow | Smaller, duller yellow |
Feet | Full feathered | Partially bare |
Range and Habitat
The ranges and habitat preferences of the greater and lesser prairie chickens also differ:
Greater prairie chickens historically occupied tallgrass and mixed grass prairies across much of the midwestern and central United States. They were found from Canada south to Texas and east into Indiana. Today, agricultural land conversion has fragmented their habitat, restricting them mainly to Kansas, Nebraska, South Dakota, Minnesota, and small parts of surrounding states. They prefer a habitat mosaic that includes native grasses, forbs, and shrubs interspersed with crop fields.
Lesser prairie chickens have a more southerly distribution. They are native to the shortgrass prairies and shrublands of Colorado, New Mexico, Oklahoma, and Texas. Much of their preferred arid habitat has been altered by livestock grazing practices and the lesser prairie chicken now occupies a very fragmented range.
Behavioral Differences
The breeding displays of the two species help highlight some of their behavioral differences:
Mating Displays
Greater prairie chickens congregate at communal lek sites in spring to perform elaborate breeding displays. Males compete for status on booming grounds and inflate their tympanums to create resonant booming sounds – they can boom for hours trying to attract females. Females visit the leks and select mates from the group of males.
Lesser prairie chickens gather in smaller leks, often in sparse shrublands. Their displays appear less vigorous overall. Male “booming” is higher pitched, less frequent, and does not carry as far.
Nesting and Brooding
Female greater prairie chickens build nests in dense vegetation relatively far from the lek sites. Males do not participate in parenting and play no role defending the nest or young. Nests are often destroyed by hay harvesting in agricultural areas.
Lesser prairie chicken females nest closer to leks and males will help defend nesting areas. They also prefer nesting in less dense shrub cover. Early spring storms and predators take a toll on nests and chicks of both species.
Roosting and Foraging
During fall and winter, greater prairie chickens form large roosting flocks called droves that number in the hundreds of birds. Lesser prairie chickens roost in much smaller flocks.
Both species forage on the ground for seeds, leaves, and insects but greater prairie chickens seem to prefer more cultivated grains and will sometimes perch in trees, while lesser prairie chickens are more prone to forage on native plants like sagebrush.
Conservation Status
Due to significant population declines over the past century, both prairie chicken species are considered threatened:
– The greater prairie chicken is listed as Vulnerable on the IUCN Red List of Threatened Species. It is also listed as Endangered in Canada. Overall populations have declined by about 90% from historical levels. They now number around 200,000 mature individuals across their range.
– The lesser prairie chicken is listed as Vulnerable on the IUCN Red List as well. It is estimated their population has declined over 90% since the 1800s. Current population estimates are around 30,000 mature individuals.
Habitat loss from agriculture is the main threat facing both species. Additional conservation challenges include habitat fragmentation, livestock grazing, energy development, predation, and climate change impacts. However, managed grazing practices and habitat restoration efforts focused on maintaining native prairies have helped stabilize some populations. Long-term monitoring and adaptive habitat management will be important for the future preservation of these species.
Key Differences Summary
Characteristic | Greater Prairie Chicken | Lesser Prairie Chicken |
---|---|---|
Size | Slightly larger | Slightly smaller |
Plumage | More distinct barring | Paler, less barring |
Air Sacs | Large and bright orange | Smaller, duller yellow |
Display Behavior | Elaborate booming displays | Less vigorous displays |
Nesting | Far from leks, no male involvement | Near leks, males help defend |
Wintering | Large flocks | Smaller flocks |
Foraging | Cultivated grains | More native plants |
Range | Northern Great Plains | Southern Shortgrass Prairie |
Conservation Status | Endangered in Canada, Vulnerable overall | Vulnerable |
Conclusion
In conclusion, while the greater and lesser prairie chickens share many similarities being closely related grouse species, they can be distinguished by size, coloration, behavioral traits, geographic range, habitat preferences, and conservation status. Ongoing conservation efforts focused on preserving native prairie habitat will be crucial for ensuring the future survival of both of these threatened species. Their unique mating displays and place in the ecology of the Great Plains makes them important species to protect. Comparing the similarities and differences between the greater and lesser prairie chicken highlights the diversity of the prairie grouse family.