Small mammal response to establishing blowout penstemon habitat in the Sandhills of Nebraska
Principle Investigators
Dr. Keith Geluso, University of Nebraska Kearney
Dr. Carter Kruse, Turner Institute of Ecoagriculture
Graduate Student
Levi Fettig, MS Candidate
Rationale.
Blowout penstemon is considered an endemic, successional species found only in and around sand blowouts in western Nebraska and eastern Wyoming. Historically, blowout penstemon was common across the Nebraska Sandhills, but in 1987 the species was listed as an endangered species and is currently known as the “rarest species native to the Great Plains region”. Today, only a few small populations remain, primarily due to sand dune stability, which is likely the result of current moisture patterns and modern grazing management in the Sandhills. Thus, restoration and conservation of this penstemon species requires development of suitable habitat by intentionally managing (e.g., grazing, mechanical, etc.) for disturbance that creates bare and blowing sand. Historically widespread, today these sand blowouts represent a microhabitat in a grassland landscape. Ecologically, penstemon habitat may be important for other groups or communities of species adapted to this early successional habitat. The Institute conducted this project to measure the implications of creating blowout habitats for penstemon recovery on the local small mammal community, as well as other terrestrial and avian species.
Outcomes.
Disturbances on landscapes affect species differently, with some species impacted negatively whereas others require it to survive. Blowout penstemon (Penstemon haydenii) is an early successional species that requires disturbance of sandy habitats in the Sandhill Region of Nebraska to persist. We studied the effects of intentionally creating a large-scale sandy habitat on the small mammal community during restoration management for the endangered blowout penstemon. We trapped small mammals and compared species abundances between three upland habitats with low, medium, and high amounts of disturbance. We also measured distances traveled by rodents to cover or burrows after release between treatments. Habitat generalists, like western deer mice (Peromyscus sonoriensis) and northern grasshopper mice (Onychomys leucogaster), had similar abundances across all three habitats. In contrast, differences in abundances were observed for habitat specialists. Ord’s kangaroo rat (Dipodomys ordii), a bipedal and open habitat species, was captured more frequently in the open sandy penstemon restoration site, whereas the quadrupedal and cover-obligate plains pocket mouse (Perognathus flavescens) had significantly lower abundances within the penstemon restoration site and thrived in the sod–forming grass habitat. We also noted differences among treatments for distances traveled back to cover, with generally greater distances traveled in the open sandy penstemon treatment where there was relatively less ground cover. Ord’s kangaroo rat, the most abundant rodent species in the restored penstemon pasture, is a granivorous species known to disperse seeds in small shallow depressions throughout their territories, a habit that might benefit blowout penstemon via a mutualistic interaction.
