Recently published estimates on lesser prairie-chickens from the Western Association of Fish and Wildlife Agencies (WAFWA) indicate good news for the species across its range which includes the states of Colorado, Kansas, Oklahoma, New Mexico, and Texas. The latest lesser prairie-chicken aerial survey from WAFWA shows that bird population estimates remain stable from the previous survey and, more importantly, that the estimated number of birds has increased since surveys began in 2012. These estimates are further bolstered by the detailed ground surveys performed this spring by Colorado Parks and Wildlife.
Colorado’s lesser prairie-chickens are found in the Sand Sagebrush Ecoregion, which includes parts of SE Colorado, SW Kansas, and the Oklahoma Panhandle. Although the estimate from the WAFWA aerial surveys shows a decrease in the Sand Sagebrush Ecoregion, CPW’s higher ground counts in that region indicate that Colorado lesser prairie-chicken numbers have actually increased from the past several years. As reported this spring, CPW estimates that there were over 300 breeding adults in Colorado at the time of the ground surveys.
Why do the numbers look so different? One explanation for the discrepancy in estimates may include a shift in the bird’s distribution and the fact that the aerial surveys no longer cover portions of occupied habitat. Recently, CPW has documented new breeding areas resulting from a translocation effort as well as a natural shift to the north. Survey design also plays a role – the aerial surveys are designed to measure long-term, range-wide trends. For long-term trends, it is important to survey the same areas through time. In addition, the aerial surveys were designed to provide accurate annual estimates for the range-wide population, however, yearly estimates can be quite variable for low-density areas such as the Sand Sagebrush Ecoregion. Biologists often refer to 3-year rolling averages as a way to smooth out this annual variation, and the goal of the surveys was to document trend over 10 years.
In CPW’s surveys, not only did surveyors count more chickens on breeding grounds, known as leks, but they found them in new locations. For example, birds were counted in Prowers County where lesser prairie-chickens haven’t been seen in years, but now appear to be making a comeback. Lekking birds were also found in areas north of known lesser prairie-chicken range, where they’d never been documented before. So what explains this turnaround in chicken numbers and range expansion?
The success of the lesser prairie-chicken in this ecoregion depends on a number of factors, including precipitation, size and the right grass species in the habitat, and solid working partnerships formed between federal and state agencies and private landowners.
Another likely driver of the population increase is a four-year conservation project carried out by CPW and partners to provide for a sustainable population in the Sand Sagebrush Ecoregion. From 2016-2019, CPW, Kansas Department of Wildlife, Parks and Tourism (KDWPT), and Kansas State University (KSU) caught over 400 wild lesser prairie-chickens in central Kansas and translocated them to the Comanche and Cimarron National Grasslands in SE Colorado and SW Kansas. In 2016, the population had gotten so low on the Comanche National Grasslands and all of Baca County, Colorado that only one lek with 2 males was observed. This spring, one year after the translocation project was completed, there were 46 males found across 6 new leks in Baca County. CPW and our partners are optimistic about the long-term implications of the new leks in the Sand Sagebrush Ecoregion.
Overall, the spring 2020 lesser prairie-chicken lek counts show that, together with our partners in Kansas, CPW ’s efforts to recover and restore this iconic species to SE Colorado and SW Kansas are working. This video captures the effort and dedication of these partnerships to ensure the future health of the lesser prairie-chicken in Colorado.
For additional information on the lesser prairie-chicken and other wildlife conservation efforts in the state, visit cpw.state.co.us.