Contributed Paper
ROOM: HCCC, Room 15

8:30AM Variable Response to Energy Development and Rangeland Management Practices By a Declininggrouse Species Throughout the Annual Cycle.
David Londe; Samuel Fuhlendorf; Dwayne Elmore; Craig Davis
Grasslands are among the most threatened ecosystems in the world due to widespread conversion to other land uses, and many remaining grasslands face additional conservation threats such as altered fire regimes and fragmentation from energy development. Understanding how wildlife species respond to human activities in grasslands will be critical for the conservation of grassland fauna. We examined habitat use of female greater prairie-chickens (Tympanuchus cupido), a declining North American grouse species, in a grassland that is managed with prescribed fire and grazing and has also undergone considerable development for oil and gas development. We developed discrete choice models for four behaviorally distinct life history stages to evaluate how habitat use may change through the year in relation to rangeland management and energy development. We found that time since fire, avoidance of woodlands, and use of areas near lek sites were the most consistent predictors of habitat use during most periods. Use of time since fire varied through the year with hens primarily using unburned patches in the lekking and nesting season and recently disturbed patches in the post-nesting and nonbreeding season. Additionally, greater prairie-chickens demonstrated a seasonally dependent response to energy development, avoiding power lines and high densities of oil wells in the post-nesting and nonbreeding season. Management actions that promote heterogeneity will benefit greater prairie-chickens by creating a variety of seral stages used during different life stages, but efforts should be made to limit future fragmentation of grasslands by energy development. Further, energy development may limit the utility of heterogeneity based management through displacement of individuals and loss of usable space for greater prairie-chickens.
8:50AM Effect of Grazing Management Systems on Space Use By Cattle and Lesser Prairie-Chickens
Christopher K. Gulick; Jonathan D. Lautenbach; David A. Haukos
The lesser prairie-chicken (Tympanuchus pallidicinctus) is a prairie grouse species that has experienced large declines in occupied range and population. These declines are associated with anthropogenic encroachment, climate change, and mismanagement of remaining expanses of intact prairie. With >90% of the lesser prairie-chicken range managed by private landowners, understanding fine-scale effects of different management practices on habitat is of chief importance. Lesser prairie-chicken home ranges occur within large swaths of continuous grassland that contain a variety of vegetative resources used by lesser prairie-chickens during different life stages, such as the nesting and brooding periods of female lesser prairie-chickens. It remains unclear as to which management strategies best mimic historical disturbance patterns to provide the optimal distribution of resources for lesser prairie-chickens, relative to fine-scale movements of large herbivores. To determine this, we simultaneously tracked cattle (Bos taurus) and lesser prairie-chickens using GPS telemetry over two treatments, corresponding to patch-burn grazed and rotationally grazed management regimes. We used kernel density functions to create 50%, 75%, and 99% isopleth cattle home ranges in each pasture, corresponding to high, medium, and low cattle densities, respectively. We did not find any difference between cattle home range sizes between treatments. We measured vegetation characteristics at random locations within both treatments and found that visual obstruction and percent cover of grass, forbs, and bare ground differed between treatments. In the patch-burn grazed treatment, these variables also differed among gradients of cattle density. Both systems are effective tools in managing habitat for lesser prairie-chickens at different life history stages. Results from this study will guide management practices affecting fine-scale cattle movements and subsequently influence resource distributions for lesser prairie-chickens.
9:10AM The Effects of Electric Power Lines on the Breeding Ecology of Greater Sage-Grouse
Michel T. Kohl; Terry A. Messmer; Benjamin A. Crabb; David K. Dahlgren; Randy T. Larsen; Shandra N. Frey; Sherry Liguori; Rick J. Baxter
Anthropogenic infrastructure can negatively affect wildlife. Grassland birds may be particularly vulnerable to tall anthropogenic structures because they evolved in ecosystems void of vertical structures. In the western U.S., electric power transmission and distribution lines occur within the range of the greater sage-grouse (Centrocercus urophasianus; sage-grouse). The U.S. Fish and Wildlife Service recommended using buffer zones near leks to mitigate the impacts of power lines on sage-grouse. However, because data are lacking, recommended buffer zones are inconsistent across state and federal agencies. To address this, we evaluated the effects of power lines on sage-grouse breeding ecology within Utah and the surrounding areas from 1998-2013. To identify behavioral and demographic thresholds (i.e., buffers) we used linear piecewise splines within a Resource Selection Function or Generalized Linear Model framework. Power lines negatively affected lek trends and persistence at distances up to 2.7 and 2.8 km, respectively. Female sage-grouse were displaced by transmission lines during the nesting and brooding seasons at distances up to 1.1 and 0.8 km, respectively. Nest and brood success reduced by transmission lines up to distances of 2.6 and 1.1 km, respectively. Distribution lines did not affect sage-grouse habitat selection or reproductive fitness. Moreover, our analyses demonstrated the value of habitat quality in mitigating power line impacts. Thus, conservation planners can minimize the effects of new power lines by placing them in existing anthropogenic corridors and/or incorporating no surface occupancy buffers within 2.8 km from active leks. Given this is the first landscape-level comparison examining the relationship between power lines and sage-grouse breeding habitat, our results are relevant to sage-grouse management as well as other galliformes that are affected by anthropogenic structures. In addition, the splines technique we used here can applied more broadly to evaluate the effects of anthropogenic structures on a wide variety of wildlife species.
9:30AM Assessing Greater Sage-Grouse Nest Selection and Success on the Fringe
Lindsey A. Parsons; Travis Runia; Andrew Gregory; Jonathan A. Jenks
Nest success is a demographic driver in Greater Sage-Grouse (Centrocercus urophasianus) populations. Landscape characteristics driving nest-site selection are important for managing habitat, specifically if they impact nest survival. However, little is known about factors affecting nest survival and selection on the fringe of their range, in South Dakota. In 2016 and 2017, we detected 70 nests in South Dakota. Vegetation measurements were collected at nest-sites, and two random sites within 3.3 km of nests. Nest-site selection was compared at two scales; within 1m of nest and within 50m of nest. Differences between used and random sites were analyzed using a multivariate Hotelling’s t- test. Variables included; total canopy cover, grass canopy cover, litter cover, shrub canopy cover, grass height, Visual Obstruction Reading (VOR), and nest shrub height and volume. Results indicated a significant difference (P<0.05) at the 1m scale, and no difference at the 50m scale. Post hoc two sample t-tests conducted for the 1m scale indicated nests had significantly (P<0.01) larger nest shrubs (height and volume), taller grass, higher VOR, greater shrub canopy cover, and less grass canopy cover than random sites. Nest survival was calculated using program MARK. Models were evaluated using AIC corrected for small sample size (AICc ). Covariates included; total canopy cover, grass canopy cover, shrub canopy cover, grass height, VOR, nest shrub height, and landownership (public or private). The top model (model with lowest AICc) included landownership, followed by constant survival which was >2 ΔAICc units from other potential models. Nests on public lands had an estimated Daily Survival Rate (DSR) of 0.972 ± 0.01 whereas nests on private lands had an estimated DSR of 0.939 ± 0.007. Determining the underlying difference between public and private lands is critical to improving nest success on both.


Contributed Paper
Location: Huntington Convention Center of Cleveland Date: October 11, 2018 Time: 8:10 am - 9:50 am