Greater Prairie-Chicken

Permanent resident; an uncommon species during the Minnesota Breeding Bird Atlas (MNBBA).

Formerly widespread throughout the grasslands of the Great Plains and Upper Midwest, the Greater Prairie-Chicken is now largely restricted to the northern Great Plains states of North Dakota, South Dakota, Nebraska, Kansas, and northwestern Minnesota (Figure 1). Scattered populations are found father south and east of the core breeding range. Three subspecies are recognized: (1) the Heath Hen (Tympanuchus cupido cupido), originally found in the northeastern United States and now extinct; (2) the Attwater’s Prairie-chicken (T. c. attwateri), which is now restricted to the central Gulf coast of Texas and is federally endangered; and (3) the Greater Prairie-Chicken (T. c. pinnatus).

A game species, the Greater Prairie-Chicken was assigned a 15/20 Continental Concern Score by Partners in Flight and designated a Yellow Watch List species; officially listed as a state Special Concern Species in Minnesota and designated a Species in Greatest Conservation Need by the Minnesota Department of Natural Resources.

Historically Greater Prairie-Chickens undertook short-distance migratory movements, and females moved farther south than males. Roberts (1932) included several accounts of large flocks from Minnesota and northern Iowa moving to Missouri for the winter; the movements were presumably more pronounced in severe winters. Today the birds are largely nonmigratory, moving only short distances (up to 30 miles) (Svedarsky and Van Amburg 1996). Some researchers have suggested that as populations have declined, there is less competition for food during the winter months. At the same time, the grassland landscape has become more fragmented by agricultural lands, which provide abundant winter food resources, thereby reducing the necessity for moving south as temperatures fall (Johnson et al. 2011).

Omnivorous; consumes a wide variety of insects, leaves, fruits, and seeds; waste grains are important during the winter months.

Ground nest built in a shallow depression.

The Greater Prairie-Chicken was an original inhabitant of the midwestern tallgrass prairie. The full extent of the Greater Prairie-Chicken’s distribution prior to European settlement is imprecisely known, but its core likely stretched from the central plains states of Nebraska, Kansas, and Oklahoma east to Illinois, Indiana, Ohio, and Kentucky (Johnson et al. 2011). Its status in Minnesota at that time is unclear; it may have been a rare species in the very southeastern corner of the state in the early 1800s (Schrader and Erickson 1944; Partch 1973; Hoch 2011).

What is undisputed is the rapid spread of the species across Minnesota as settlers turned the prairie sod into productive agricultural fields and began clearing the dense northern forest for its valued timber. Although the Greater Prairie-Chicken would become the symbol of prairie conservation efforts in the state, it is a relative newcomer to the state’s western grasslands, having forced the northern retreat of the truly native grassland grouse the Prairie Sharp-tailed Grouse (Roberts 1932). The latter, however, is more dependent on savanna-like conditions, where prairies are interspersed with open woodlands. The adaptable prairie-chicken, on the other hand, favors more open country and was more suited to the wide-scale conversion of the state’s sweeping prairie landscape and the mosaic of small farms, croplands, pastures, and hayfields that followed the plow in the 19th century. Making its home in the agricultural landscape, the species became an important game bird to the early settlers.

Many articles and technical papers provide today’s student of Minnesota birds with accounts of the species’ history in the state (e.g., Hatch 1892; Roberts 1932; Schrader and Erickson 1944; Erickson and Petraborg 1952; Partch 1970, 1973; Svedarsky et al. 1997; Hoch 2011). The Greater Prairie-Chicken was not reported by those who explored the region centuries ago, such as Father Hennepin, Jonathan Carver, and later, Henry Schoolcraft. Thus, Hatch’s first comprehensive report about Minnesota birds provides one of the earliest known accounts of the species’ appearance in the state (Hatch 1892). Hatch’s good acquaintance the Reverend E. G. Gear was a chaplain stationed at Fort Snelling beginning in 1839. A natural history buff, he remarked that the prairie-chickens “were seldom seen at the first, but after the country began to become settled considerably, they increased in numbers perceptibly from year to year.”

From that point forward, the species’ progression across the state was well documented. Partch (1970) compiled numerous excerpts from the literature to map various fronts of the species’ expansion northward and westward. Hoch (2011) briefly summarized dates and places that marked the species’ progression. After being reported at Fort Snelling by Reverend Gear in approximately 1839, the birds moved northwest, reaching St. Cloud by 1860, and the North Dakota border near Moorhead by 1879. Just two years later, they were reported in Kittson County by Roberts, who saw 3 in a group of Sharp-tailed Grouse that were shot near the town of Hallock. Although residents in the area reported the chickens had only recently appeared in the region, four years later they were considered abundant throughout much of the Red River valley. Partch (1973) estimated the movement across the prairies proceeded at a rate of approximately 16 km per year.

Their progression into the state’s forest region was considerably slower. Nevertheless, logging and wetland drainage, followed by the establishment of small farms enabled the species to expand even into the northern forest landscapes of Minnesota, Michigan, Wisconsin, and Ontario (Svedarsky et al. 2000). Prairie-chicken’s became established in forest clearings in the Mille Lacs region as early as 1885 and appear to have reached Duluth and the North Shore of Lake Superior in the late 1880s or early 1900s. But from its first appearance at Mille Lacs, nearly 20 years would pass before it was observed along the Iron Range in west-central St. Louis County in 1906, and in Itasca County in 1921 (Roberts 1932). At its peak abundance in the early 1900s, biologists estimated that its range covered nearly 92% of the state (Hoch 2011). Yet, as widespread as the species presumably occurred, Roberts reported confirmed nesting records (nests with eggs) from only 6 counties stretching only as far east as Kandiyohi and Meeker Counties: Grant (1924), Kandiyohi (1881), Kittson (1929), Meeker (1891), Otter Tail (1926), and Pipestone (1914). An adult with a young brood was also reported from Polk County (1928).

Although its numbers surged as it expanded across the state, the Greater Prairie-Chicken’s heyday was short-lived. As Roberts (1932) noted, it is an easy bird to shoot. When flushed, “it flies off in a direct course” and makes an easy target for the hunter’s gun. Despite the enactment of some hunting regulations as early as 1858, most restrictions were blatantly ignored until the early 1900s (Swanson 1940). Indeed, in the latter half of the 19th century, it was not unusual for hunters to take 50 to 100 birds per day (Swanson 1940). As late as 1932, Roberts went to great length to admonish hunters for the excessive take: “Unless sportsmen’s organizations become less selfish and more willing to practice instead of vainly preach conservation, the days of the Prairie-Chicken are numbered.” In just 10 years the estimated take in Minnesota during the hunting season declined from 328,914 birds in 1923 to only 29,216 in 1933 (Erickson and Petraborg 1952). By 1942 the season was closed.

Hunting pressures certainly reduced population numbers significantly, but other changes were underway in the early 20th century that influenced the prairie-chicken’s present distribution. Most important was the intensification of agricultural practices. New machines made it more efficient to farm large, uniform fields, which replaced the original mosaic of pastures, croplands, and native grasslands that provided ideal year-round habitat for the birds. By and large, when croplands comprised 20% to 30% of the landscape, the birds did well, but when croplands exceeded that percentage, they declined (Svedarsky et al. 1997, 2003). Rather than retreating to southern Minnesota, their first gateway to the state, the dwindling numbers retreated to the unplowed prairies remaining along the old gravel beach ridges of former Glacial Lake Agassiz in northwestern Minnesota. A small, isolated population also remained farther east, in the vicinity of Wadena.

In 1975, Green and Janssen described the species’ distribution as restricted largely to the grasslands of northwestern Minnesota, from Wilkin County north to Polk and Red Lake Counties. The small eastern population in Wadena and Cass Counties also persisted. The population decline that Roberts (1932) witnessed in the early 1900s continued through the 1960s. Resident flocks that “were present in Fillmore and Mower Counties until the late 1930s” were long gone. Birds were last seen near Duluth in 1952 and “an outlying population in Morrison County” was last seen in 1965.

Several years later, Janssen (1987) reported that a 1983 census estimated 1,500 males on booming grounds. The population, he noted, “has remained fairly stable over the past five years with some increases noted; this is probably due to more accurate censusing than to actual increase in birds.” Small numbers of birds had even been recently discovered in Hubbard and Marshall Counties. Since 1970, confirmed nesting reports were limited to Clay and Chippewa Counties. Their presence in Chippewa County was the result of reintroduction efforts by the Minnesota Department of Natural Resources in the early 1980s. In 1998, Hertzel and Janssen added Mahnomen and Wilkin Counties to the list of counties with confirmed nesting. When the Minnesota Biological Survey was working in western Minnesota in the late 1980s, they identified 60 breeding season locations for the species. With the exception of a few reports from eastern Wadena and western Cass Counties, all locations were located in northwestern Minnesota, from southwestern Otter Tail County north to northwestern Polk County (Minnesota Department of Natural Resources 2017).

Today, the northwest region remains the Greater Prairie-Chicken’s stronghold in Minnesota. Intensive field studies have vastly improved the understanding of the species’ management needs, leading to a gradual increase in numbers. In addition, a concerted effort has been made by state and federal resource agencies and conservation organizations to protect and restore the state’s critical grassland resource. Now closely monitored, the status of the population has improved to the point that hundreds of birds have been used for at least four reintroduction projects, including in the states of Illinois and North Dakota and in the grasslands in Minnesota’s upper Minnesota River valley (Svedarsky et al. 1997; Roy 2016). A limited hunting season was also established in the fall of 2003, with the average annual take approximating 120 birds (Roy 2016).

During the MNBBA, participants reported 394 Greater Prairie-Chicken records from 3.0% (142/4,784) of the surveyed atlas blocks and from 1.7% (39/2,337) of the priority blocks. Breeding evidence was gathered in just 10 survey blocks (Figures 2 and 3; Table 1). The birds were documented in 20 of Minnesota’s 87 counties (Chippewa County was included because one atlas block straddled Chippewa and Lac qui Parle Counties) and were confirmed breeding in 4 counties. Atlas efforts were aided immeasurably by the contribution of prairie-grouse survey data from the Minnesota Department of Natural Resources.

The Glacial Lake Agassiz beach ridges remain the core of the species’ range. Small numbers also persist in Wadena County, and the small population reintroduced into west-central Minnesota, in the upper reaches of the Minnesota River, is faring well. Outside of these known populations, isolated observations were documented in far northern Kittson County and, to the south, in Pipestone County; the latter was 1 of 4 breeding records (a hen with 4 young found in a location where a male was booming in the spring). Although many predicted the demise of the prairie-chicken nearly 100 years ago, this adaptable bird has become, with considerable help from conservation organizations and resources agencies, a healthy and beloved representative of Minnesota’s grassland resource.

The Greater Prairie-Chicken’s story in Minnesota was replicated throughout much of its breeding range from the mid-1800s to the present. As Johnson et al. (2011) note in their comprehensive review of the species, much of the data available on its historical distribution are based on “hypothetical distributions of appropriate habitats, both anecdotal and objective accounts, and inferences from phylogenetic and demographic historical accounts.” Despite this uncertainty, Greater Prairie-Chickens are known to be extirpated in 12 states and provinces and rare to uncommon elsewhere. Johnson and his colleagues also provide a detailed account of all the efforts that have been undertaken to reintroduce the birds to former breeding habitats and/or to augment small, remnant populations.

*Note that the definition of confirmed nesting of a species is different for Breeding Bird Atlas projects, including the definition used by the Minnesota Breeding Bird Atlas, compared with a more restrictive definition used by the Minnesota Ornithologists’ Union. For details see the Data Methods Section.

Scores have been written on the breeding habitat requirements of the Greater Prairie-Chicken, including numerous field studies and technical reports by Dan Svedarsky and his students and colleagues at the University of Minnesota Crookston (e.g., Svedarsky 1979, 1983, 1988; Svedarsky et al. 1986, 1997, 2000, 2003).

Although the species is typically classified as an obligate grassland species, its habitat requirements are complex and differ during each stage of the life cycle. The breeding season is officially launched when the birds gather each spring at traditional display grounds, or leks. With most of the male’s energy focused on performing its legendary dance and emitting, with much pomp and circumstance, the characteristic “boom” from its inflated, orange air sacs, habitats that provide good visibility are essential. Not only must the females have full sight of the eligible males, the males must have enough range of sight to easily spot potential predators. As a result, patches of bare ground or grasslands with very low vegetation (<15 cm in height) over a wide area are critical (Svedarsky et al. 2003). Sites that are on a small rise are often selected (Johnson et al. 2011).

While the male needs habitat that ensures visibility, the nesting female requires cover that provides concealment and protection yet still enables her to detect predators and to respond with a quick flush when disturbed. The structural features of the nesting cover generally are more important than the composition of the vegetation. Planted cover on Conservation Reserve Program (CRP) lands is used extensively. Although one study demonstrated that nesting success was higher in native grasslands, more nests were found in CRP lands, which suggested either a preference for these sites or their greater availability at the time (Svedarsky et al. 2003).

Habitat used by the broods often differs from the female’s nesting habitat. Brood habitat provides good food resources (insects for the young chicks) and concealment but enables movement. In Minnesota, nearly 70% of the brood habitat was located in sites recently disturbed by mowing, grazing, or burning (Svedarsky 1979).

At the landscape scale, the Greater Prairie-Chicken is recognized as an area-sensitive species, responding both to patch size and the composition of the overall landscape (e.g., Winter et al. 2001). During a four-year study in northwestern Minnesota, 95% of the birds were observed on grassland tracts that were larger than 200 ha; no individuals occurred on tracts smaller than 50 ha. In addition, landscapes surrounding suitable habitat supported little woody vegetation (Figure 4).

Using data gathered from the federal Breeding Bird Survey (BBS), biologists have estimated the North American Greater Prairie-Chicken population at 750,000 birds (Rosenberg et al. 2016). This is significantly higher than the most recent estimate a few years earlier of 400,000 birds (Partners in Flight Science Committee 2013). Although the BBS is not a statistically robust monitoring tool for prairie-chickens, the data collected since 1966 show a decidedly upward trend in recent years. Since 1966, BBS data demonstrated a nonsignificant annual increase of 2.80% per year (Sauer et al. 2017).

In Minnesota, Svedarsky and his colleagues (2000) compiled various statewide estimates from 1968 through 1997, which suggest a population peak in the late 1970s followed by a significant decline (Table 2). Four states’ populations comprise at least 96% of the entire U.S. population: Kansas, Nebraska, South Dakota, and Oklahoma. Throughout this period, Minnesota’s population was consistently less than 1% of the entire U.S. population, ranging from an estimated high of 5,000 birds in 1968 to a low of 1,600 in 1985.

In Minnesota, some of traditional booming grounds were surveyed in the 1950s and 1960s, but in 1974, members of the Minnesota Prairie-Chicken Society launched a more comprehensive survey effort, counting males on each known booming ground at least twice during the spring display season with volunteers from multiple agencies and conservation organizations (Svedarsky et al. 1997). This effort served as a benchmark for the status of Minnesota’s Greater Prairie-Chicken population for 40 years. After the Minnesota Department of Natural Resources established a limited hunting season in 2003, it launched a collaborative effort with the society to design and implement a standardized survey in 2004. The standard metric for monitoring prairie-chickens is the average number of males observed per booming ground and the number of booming grounds per km². Although the number of booming grounds per km² has remained relatively stable since approximately 2008, the average number of males per booming ground has steadily declined. In 2007, the survey tallied a total of 1,618 males and 114 booming grounds; in 2016, surveyors tallied only 634 males on 60 booming grounds (Roy 2016).

Because a more standardized survey protocol is now used, the results are not strictly comparable with the surveys conducted by the Prairie-Chicken Society years ago. Nevertheless, during the five-year period from 1980 to 1984, volunteers tallied an average of 1,302 males on an average of 128 booming grounds (Wolfe 1984).

Specific reasons for the downturn in Greater Prairie-Chicken numbers are unknown, but the recent decline in enrollment of CRP acreages is certainly a concern. Thousands of acres have been lost in Minnesota. Nationwide, only 24.2 million acres of land were enrolled in CRP in the fall of 2015 compared to a peak enrollment of 36.8 million acres in 2007 (U.S. Department of Agriculture 2015). Given the importance of CRP lands to prairie-chickens, this loss of suitable habitat has no doubt impacted the population. There also is historical and recent evidence suggesting the species experiences 10-year population cycles not unlike that observed in Ruffed Grouse (Roberts 1932; Carlson 1942; Toepfer 2007). The relative significance of the loss of suitable habitat, a natural low in the population cycle, and recent allowable harvests is unknown.

In light of its restricted distribution and small population size, Partners in Flight has assigned the Greater Prairie-Chicken a Continental Concern Score of 15/20 and designated it a Yellow Watch List species (Rosenberg et al. 2016). The latter designation is reserved for species that require “constant care and long-term assessment” to prevent further declines. In Minnesota, the Greater Prairie-Chicken has been officially classified as a state Special Concern Species since 1984 (Coffin and Pfannmuller 1988) and has been designated a Species in Greatest Conservation Need (Minnesota Department of Natural Resources 2015).

Now an enduring symbol of grassland conservation in Minnesota, the Greater Prairie-Chicken even has its own 9,000-pound, 4-meter-high statue in the west-central Minnesota town of Rothsay, the self-proclaimed prairie-chicken capital of Minnesota! In addition to being a symbol of prairie conservation, the prairie-chicken is an important ecological indicator of grassland communities. An entire suite of grassland-dependent birds are often found utilizing the same habitat, from Upland Sandpipers and Marbled Godwits to Grasshopper Sparrows and Eastern Kingbirds.

Because the Greater Prairie-Chicken is an adaptable species that utilizes restored grasslands and native prairies, its numbers now serve as a bellwether of farmland policies and prairie conservation efforts. Interagency initiatives designed to protect and restore grassland habitats are essential to the future conservation of the species; equally important are initiatives that encourage farmers to set aside grasslands from cropland production with annual payments. When farm commodity prices are high, the incentives are often not high enough to compete with the high prices available on the commodity markets.

Although through valiant efforts the species has recovered to the point where a limited harvest was reinstated in the fall of 2003, the future of the Greater Prairie-Chicken in Minnesota is not guaranteed. Prairie-chickens are dependent on large grassland landscapes, and the pressures on farmers and developers to convert grasslands to other uses is a constant challenge. Sustainability of local populations depends on many factors. Svedarsky and his colleagues (2000) recommend that 30% of the grassland cover within 1.6 km of an active booming ground be managed to provide good nesting cover (dense, short cover at 20 cm height) and that the area be readily accessible to quality brood cover. Maintaining approximately 25% of the grassland landscape in croplands is equally important as they provide an important food source, particularly during the winter.

Not only do development pressures threaten the ability to sustain these large landscapes, but high precipitation can increase woody encroachment, particularly in the eastern portion of the species’ range, including Minnesota (Svedarsky et al. 2000). Warming temperatures that are predicted to increase precipitation and storm events will only increase this challenge. An initial assessment of the species’ vulnerability to climate change ranked it as “medium” (North American Bird Conservation Initiative 2010). Given these challenges, sufficient funding for protecting and actively managing grasslands with appropriate burning, mowing, and/or grazing regimes is essential to maintain quality habitat, reduce woody encroachment, and insure that the Greater Prairie-Chicken remains a visible icon of Minnesota’s grassland communities for generations to come.