Demographic Consequences of Conservation Reserve Program Grasslands for Lesser Prairie-Chickens

Abstract

Knowledge of landscape and regional circumstances where conservation programs are successful on working lands inagricultural production are needed. Convertingmarginal croplands to grasslands using conservation programs such as the United States Department of Agriculture Conservation Reserve Program (CRP) should be beneficial for many grassland-obligate wildlife species; however, addition of CRP grasslands may result indifferent population effects based on regional climate, characteristics of the surrounding landscape, or species planted or established. Within landscapes occupied by lesser prairie-chickens (Tympanuchus pallidicinctus), CRP may provide habitat only for specific life stages and habitat selection for CRP may vary between wet and dry years. Among all study sites, we captured and fitted 280 female lesser prairie-chickens with very high frequency (VHF)- and global positioning system (GPS) transmitters during the spring lekking seasons of 2013-2015 to monitor habitat selection for CRP in regions of varying climate. We also estimated vital rates and habitat selection for 148 individuals, using sites in northwest Kansas, USA. The greatest ecological services of CRP became apparent when examining habitat selection and densities. Nest densities were approximately 3 times greater in CRP grasslands than native working grasslands (i.e., grazed), demonstrating a population-level benefit (CRP = 6.0 nests/10 km(2) +/- 1.29 [ SE], native working grassland = 1.7 nests/10 km(2) +/- 0.62). However, CRP supporting high nest density did not provide brood habitat; 85% of females with broods surviving to 7 days moved their young to other cover types. Regression analyses indicated lesser prairie-chickens were approximately 8 times more likely to use CRP when 5,000-ha landscapes were 70% rather than 20% grassland, indicating variation in the level of ecological services provided by CRP was dependent upon composition of the larger landscape. Further, CRP grasslands were 1.7 times more likely to be used by lesser prairie-chickens in regions receiving 40 cm compared to 70 cm of average annual precipitation and during years of greater drought intensity. Demographic and resource selection analyses revealed that establishing CRP grasslands in northwest Kansas can increase the amount nesting habitat in a region where it may have previously been limited, thereby providing refugia to sustain populations through periods of extreme drought. Nest survival, adult survival during breeding, and nonbreeding season survival did not vary between lesser prairie-chickens that used and did not use CRP grasslands. The finite rate of population growth was also similar for birds using CRP and using only native working grasslands, suggesting that CRP provides habitat similar to that of native working grassland in this region. Overall, lesser prairie-chickens may thrive in landscapes that are a mosaic of native working grassland, CRP grassland, with a minimal amount of cropland, particularly when nesting and brood habitat are in close proximity. (C) 2018 The Wildlife Society

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Keywords

Conservation Reserve Program, demography, landscape effects, lesser prairie-chicken, nest density, population, resource selection, strategic conservation, survival

Citation