Availability of lesser prairie‐chicken nesting habitat impairs restoration success

Abstract

Regional populations of lesser prairie‐chickens (Tympanuchus pallidicinctus) have been declining irregularly since the early 1900s (Jensen et al. 2000). Populations in the Sand Sagebrush Prairie Ecoregion of Kansas and Colorado, USA, have been experiencing declines during the last 2 decades. Ecoregion‐wide declines included the Cimarron and Comanche National Grasslands in southwestern Kansas and southeastern Colorado, respectively, from which lesser prairie‐chickens were nearly extirpated by 2016. In 2014, the United States Department of Agriculture (USDA)–Forest Service created a vegetation management plan to restore lesser prairie‐chicken nesting habitat on the National Grasslands. We used management plan recommendations to evaluate available nesting habitat on National Grasslands and surrounding areas for 394 transmitter‐marked lesser prairie‐chickens translocated to the Sand Sagebrush Prairie Ecoregion during 2016–2019. We found that a small proportion of vegetation measurements met the USDA–Forest Service's 100% visual obstruction guidelines of 25.4 to 38.1 cm (Cimarron: 5.3–21.8% of observations among cover types; Comanche: 1.5–3.0%), and grass species with a high value for nesting were rare (Cimarron: 0.5–20.1% of observations within each cover type; Comanche: 1.5–3.0%). Lesser prairie‐chickens selected for 2 of the 10 National Grasslands' cover types (shrubland state and warm season shortgrass state) during breeding season movements, but only shrubland state was selected for during nesting. Our results indicate that nesting habitat for lesser prairie‐chickens is limited on Cimarron and Comanche National Grasslands. As private grassland was also avoided during nesting, lesser prairie‐chickens in Baca and Morton counties are currently primarily relying on Conservation Reserve Program (CRP) grasslands to meet nesting habitat thresholds (Morton, KS: 17.7% CRP; Baca, CO: 16.6% CRP), which may be insufficient to sustain a viable population. Due to the impermanence of CRP, efforts to sustain local populations are likely to depend on increased improved lesser prairie‐chicken nesting habitat on National Grasslands. Grazing strategies such as rest‐rotation and year‐long deferments may provide opportunities to restore lesser prairie‐chicken habitat on sand sagebrush prairie.

Assessment of lesser prairie‐chicken translocation through survival and lek surveys

“…Forb species included slimflower scurfpea (Psoralidium tenuiflorum), winterfat (Krascheninnikovia lanata), western ragweed (Ambrosia psilostachya), broom snakeweed (Gutierrezia sarothrae), white heath aster (Symphyotrichum ericoides), common prickly pear (Opuntia monacantha), and field sagewort (Artemisia campestris; McGregor and Barkley 1986). The dominant shrub species was sand sagebrush (Artemisia filifolia; Fields et al 2006, Berigan et al 2022. Planted CRP grasslands in Kansas were seeded with a native grass-forb mixture since 1986.…”

“…The landscape had limited topography with rolling hills and shallow ravines; elevation ranged from 628–942 m (U.S. Geological Survey [USGS] 2018). Land cover in these counties was a mixture of row‐crop agriculture, U.S. Department of Agriculture Conservation Reserve Program (CRP) grassland, and native short‐grass prairie intermixed with remnant mixed‐grass prairie (McDonald et al 2014, Dahlgren et al 2016, Robinson et al 2018 a , Berigan et al 2022). Historical (1901 to 2015) mean monthly temperatures ranged from −10.8°C to 29.9°C, and annual precipitation ranged from 23.0 to 84.3 cm ($$\bar{x}$$ = 50.1 cm) in Lane County, Kansas.…”

“…These grass species included little bluestem, sideoats grama, big bluestem, switchgrass, western wheatgrass, blue grama, buffalograss, and indiangrass ( Sorghastrum nutans ). Forb species planted since 1996 included alfalfa ( Medicago sativa ), Maximillian sunflower ( Helianthus maximiliani ), white sweet clover ( Melilotus alba ), yellow sweet clover ( M. officinalis ), purple prairie clover ( Dalea purpurea ), upright prairie coneflower ( Ratibida columnifera ), and prairie bundleflower ( Desmanthus illinoensis ; Fields et al 2006, Berigan et al 2022).…”

“…Vegetation on Comanche and Cimarron National Grasslands was sand sagebrush prairie, with patches ranging from sparse to abundant densities of sand sagebrush. Vegetation composition and structure on the National Grasslands was largely dependent on grazing intensity and soil type (Berigan et al 2022). Composition included both short‐ and mixed‐grass prairie interspersed with tall grasses and sand sagebrush.…”

“…Nearly 20% of the ecoregion area is comprised of the U.S. Forest Service Cimarron and Comanche National Grasslands in Kanas and Colorado, respectively, which combined is the largest area of publicly managed lands throughout the lesser prairie‐chicken range (Elmore and Dahlgren 2016). However, in 2016, lek surveys indicated <10 lesser prairie‐chickens remained in Baca County, Colorado, and that lesser prairie‐chickens were locally extirpated from Morton County, Kansas, where the majority of the Comanche and Cimarron National Grasslands are located, respectively (Berigan et al 2022). With the combined implementation of a lesser prairie‐chicken management plan by the Comanche and Cimarron National Grasslands in 2014 and increased precipitation following the 2010–2014 intensive drought, habitat quality was thought to have improved sufficiently to support a lesser prairie‐chicken translocation to the study area (U.S. Forest Service 2014).…”