Hybridization is a natural process at species-range boundaries that may variably promote the speciation process or break down species barriers but minimally will influence management outcomes of distinct populations. White-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) have broad and overlapping distributions in North America and a recognized capacity for interspecific hybridization.In response to contemporary environmental change to any of one or multiple stillunknown factors, mule deer range is contracting westward accompanied by a westward expansion of white-tailed deer, leading to increasing interactions, opportunities for gene flow, and associated conservation implications. To quantify genetic diversity, phylogenomic structure, and dynamics of hybridization in sympatric populations of white-tailed and mule deer, we used mitochondrial cytochrome b data coupled with SNP loci discovered with double-digest restriction site-associated DNA sequencing.We recovered 25,018 SNPs across 92 deer samples from both species, collected from two regions of western Kansas. Eight individuals with unambiguous external morphology representing both species were of hybrid origin (8.7%), and represented the product of multi-generational backcrossing. Mitochondrial data showed both ancient and recent directional discordance with morphological species assignments, reflecting a legacy of mule deer males mating with white-tailed deer females. Mule deer had lower genetic diversity than white-tailed deer, and both mitochondrial and nuclear data suggest contemporary mule deer effective population decline. Landscape genetic analyses show relative isolation between the two study regions for white-tailed deer, but greater connectivity among mule deer, with predominant movement from north to south. Collectively, our results suggest a long history of gene flow between these species in the Great Plains and hint at evolutionary processes that purge incompatible functional genomic elements as a result of hybridization. Surviving hybrids evidently may be reproductive, but with unknown consequences for the future

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.

Citation: Ricketts, A. M., and B. K. Sandercock. 2016. Patch-burn grazing increases habitat heterogeneity and biodiversity of small mammals in managed rangelands. Ecosphere 7(8):e01431. 10.1002/ecs2.1431Abstract. Habitat heterogeneity is a key driver of biodiversity in many ecosystems. Wildlife inhabiting the native prairies of North America evolved in a heterogeneous mosaic of habitat conditions created by fire and grazing by native ungulates. Current rangeland management practices in the tallgrass prairie ecosystem evenly distribute fire and grazing across management units and promote homogeneous habitat conditions. Patch-burn grazing is a rangeland management strategy that seeks to restore heterogeneity to rangelands via fire-grazing interactions. Our 3.5-year study tested the effects of patch-burn grazing on habitat heterogeneity and small mammal community dynamics in the Flint Hills ecoregion of eastern Kansas. To study the ecological effects of patch-burn grazing, we sampled habitat conditions and the small mammal community. We assessed habitat conditions once each growing season in a negative control that was annually burned and grazed, a positive control that was burned every four years and ungrazed, and within each of three units of a patch-burn grazing experiment (PBG) managed with rotational fire. Habitat conditions were significantly different among treatments, and a principal components analysis showed that the patch-burn grazing treatment had higher canopy cover of forbs and habitat heterogeneity than our two control units. To sample the small mammal community, we conducted monthly live trapping of small mammals on two randomly located trap grids in each of our two controls and three units of our PBG treatment. Small mammal diversity was significantly higher in the patch-burn grazing treatment and in the positive control, vs. the negative control. Moreover, a canonical correspondence analysis showed that a fire-grazing interaction was the major driver structuring small mammal communities. Patch-burn grazing is an effective strategy for restoring heterogeneity to vegetative structure and composition, and can increase biodiversity of small mammals in managed rangelands in the tallgrass prairie ecosystem.

The Flint Hills ecoregion is the largest remaining tract of native tallgrass prairie in North America. Contemporary landscape change (e.g., urbanization, agricultural production) in this region is likely affecting native biodiversity; however, we have a limited understanding of how these changes might affect carnivores. We used camera traps distributed across urban‐rural land‐use gradients, and multiseason occupancy models, to investigate the influence of landscape structure and composition on habitat occupancy dynamics of 3 native carnivores (coyote [Canis latrans]; bobcat [Lynx rufus]; and striped skunk [Mephitis mephitis]) and 1 nonnative carnivore (domestic cat) in the Flint Hills, Kansas, USA, during 2016–2017. Additionally, we assessed the potential for coyotes, the apex predator in the Flint Hills, to mediate habitat occupancy of domestic cats. We also examined the relative influence of landscape factors on native carnivore species richness and diversity. As predicted, coyotes were less likely to occupy and colonize sites, and more likely to leave sites, surrounded by urban landcover. Habitat occupancy by bobcats was positively associated with forest landcover and edge densities; however, bobcats seemed insensitive to urban landcover. Additionally, bobcats were more likely to colonize sites with more grassland and row‐crop agriculture landcover. Surprisingly, striped skunk occupancy and colonization rates at sites were negatively related to urban landcover. As expected, domestic cats were more likely to occur at and colonize sites with increased urban landcover and less likely at sites with high coyote occupancy probabilities. Carnivore species diversity and richness were negatively related to the urban landcover. Our results suggest that urban landcover may limit the spatial distributions of some native carnivores in the Flint Hills and contribute to reduced carnivore diversity. Moreover, urban landcover in the Flint Hills may provide domestic cats with refugia from intraguild pressures by coyotes. Our results provide wildlife managers with insights into how contemporary landscape change in this imperiled ecosystem may affect biodiversity conservation and maintenance. © 2018 The Wildlife Society.

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