Greater (Tympanuchus cupido) and Lesser (T. pallidicinctus) Prairie-Chicken are thought to be historically and presently allopatric. We documented an area of approximately 250 000 ha in western Kansas characterized by leks with displaying males of both species. Display booms unlike typical Greater or Lesser Prairie-Chickens were heard and recorded at nine mixed leks. Spectrograms of these vocalizations contained elements of Greater and Lesser Prairie-Chicken booms, and comparisons suggested intermediate similarity. Males giving these booms had additional novel characters as well as novel combinations of Greater and Lesser Prairie-Chicken characters, and might represent the first case of hybridization in the wild. Despliegues de Híbridos Aparentes de Tympanuchus en una Zona de Simpatría Resumen. Aunque se ha pensado que Tympanuchus cupido y T. pallidicinctus son especies histórica y actualmente alopátricas, documentamos un área de aproximadamente 250 000 ha en el oeste de Kansas que está caracterizada por asambleas de cortejo integradas por machos de ambas especies. Escuchamos y grabamos vocalizaciones de despliegue diferentes de las típicas de T. cupido y T. pallidicinctus en nueve asambleas de cortejo mixtas. Los espectrogramas de dichas vocalizaciones contenían elementos de los cantos de T. cupido y T. pallidicinctus y presentaban similitud intermedia. Los machos que emitieron esas vocalizaciones presentaban caracteres adicionales novedosos, así como nuevas combinaciones de caracteres de T. cupido y T. pallidicinctus. Éste podría representar el primer caso de hibridación de estas dos especies en condiciones naturales.

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Grazing management recommendations often sacrifice the intrinsic heterogeneity of grasslands by prescribing uniform grazing distributions through smaller pastures, increased stocking densities, and reduced grazing periods. The lack of patch‐burn grazing in semi‐arid landscapes of the western Great Plains in North America requires alternative grazing management strategies to create and maintain heterogeneity of habitat structure (e.g., animal unit distribution, pasture configuration), but knowledge of their effects on grassland fauna is limited. The lesser prairie‐chicken (Tympanuchus pallidicinctus), an imperiled, grassland‐obligate, native to the southern Great Plains, is an excellent candidate for investigating effects of heterogeneity‐based grazing management strategies because it requires diverse microhabitats among life‐history stages in a semi‐arid landscape. We evaluated influences of heterogeneity‐based grazing management strategies on vegetation structure, habitat selection, and nest and adult survival of lesser prairie‐chickens in western Kansas, USA. We captured and monitored 116 female lesser prairie‐chickens marked with very high frequency (VHF) or global positioning system (GPS) transmitters and collected landscape‐scale vegetation and grazing data during 2013–2015. Vegetation structure heterogeneity increased at stocking densities ≤0.26 animal units/ha, where use by nonbreeding female lesser prairie‐chickens also increased. Probability of use for nonbreeding lesser prairie‐chickens peaked at values of cattle forage use values near 37% and steadily decreased with use ≥40%. Probability of use was positively affected by increasing pasture area. A quadratic relationship existed between growing season deferment and probability of use. We found that 70% of nests were located in grazing units in which grazing pressure was <0.8 animal unit months/ha. Daily nest survival was negatively correlated with grazing pressure. We found no relationship between adult survival and grazing management strategies. Conservation in grasslands expressing flora community composition appropriate for lesser prairie‐chickens can maintain appropriate habitat structure heterogeneity through the use of low to moderate stocking densities (<0.26 animal units/ha), greater pasture areas, and site‐appropriate deferment periods. Alternative grazing management strategies (e.g., rest‐rotation, season‐long rest) may be appropriate in grasslands requiring greater heterogeneity or during intensive drought. Grazing management favoring habitat heterogeneity instead of uniform grazing distributions will likely be more conducive for preserving lesser prairie‐chicken populations and grassland biodiversity. © 2021 The Wildlife Society.

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Male-male competition contributes to male mating success in lekking birds, however, female choice is usually considered to be responsible for the characteristic skew in fitness among males in this mating system. I conducted intensive behavioral observations during the 2002 breeding season at two leks attended by lesser (Tympanuchus pallidicinctus), greater (T. cupido), and resultant hybrid prairie-chicken in western Kansas, following a regional-scale survey for mixed Tympanuchus leks in 2001. Sample observations of 43 individually marked males over 512 hours allowed identification of agonistic correlates of mating success, which included agonistic display behaviors, court characteristics, and attendance. I then examined how these traits differed among hybrids and their parental forms, and speculated on how hybrid status might affect mating success. Male-male competition appeared to contribute significantly to mating success in lesser and greater prairie-chicken; a total of 24 copulations were observed on the two study leks. A total of five lesser x greater prairie-chicken hybrids regularly attended and displayed; this study is the first to provide behavioral data from marked hybrids on leks. Hybrid males appeared to succeed in the male-male facet of sexual selection as indicated by regular lek attendance, central court placement, court placement adjacent to copulation hotspots, and frequencies of agonistic interactions and vocalizations that were similar to males that mated; yet hybrids failed to copulate. Vocalizations were the primary difference I detected among lesser, greater and hybrid prairie-chicken. I hypothesized that one of these vocalizations, the antiphonal boom, might be subject to intense intrasexual selection. I also provide evidence for the possible role of this vocalization in the recent evolutionary divergence of Tympanuchus.