Upland Game I

Contributed Oral

Spatiotemporal Variation and Individual Heterogeneity in Resource Selection by Lesser Prairie-Chickens
Bram Verheijen, David Haukos, Daniel Sullins

Patterns in resource selection are rarely uniform within a species, instead varying with spatiotemporal variation in resource availability and individual heterogeneity in resource needs. Because of its direct link with fitness and distribution of animals, variation in resource selection has important consequences for local population dynamics and carrying capacity. Understanding this variation is especially important for species of conservation concern where active management of species should be guided by local habitat needs. Since European settlement, the lesser prairie-chicken (Tympanuchus pallidicinctus), a species of non-migratory prairie grouse, has declined ~90% from its historically occupied range and abundance. Occurring in four distinct ecoregions, lesser prairie-chickens show range-wide similarities in resource selection as well as variation among ecoregions, sexes, and biological seasons. We tested the extent and strength of this variation by tracking lesser prairie-chickens at five sites in Kansas and Colorado, representing the three northernmost currently occupied ecoregions. Although lesser prairie-chickens selected greater amounts of grass cover on the landscape (>60% in 5-km buffer), grassland patches with lower perimeter to area ratios, and intermediate amounts of forb cover (20–40%), relative strength of selection varied among sites based on the proportion of available grassland. Lesser prairie-chickens strongly avoided trees and minor roads, but only when those features were close (<3 km), selected areas with greater shrub cover or taller vegetation at western sites, where low amounts of precipitation limit vegetation growth, and more intermediate vegetation heights at eastern sites. During the breeding season, females selected sites with taller vegetation, at lower elevations, and that were further away from trees than males, while patterns were weaker and more similar between sexes during the nonbreeding season. Observed variation in resource selection among sites and between sexes further supports the need to adapt management plans to local resource availability and needs of lesser prairie-chickens.

Why Didn’t the Chicken Cross the Road? Effects of Linear Features on Greater Prairie-Chicken Space-Use and Landscape Connectivity
David Londe, Dwayne Elmore, Craig Davis, Sam Fuhlendorf, Torre Hovick

Landscapes across the globe are becoming increasingly fragmented by anthropogenic activities. In particular, many landscapes are bec divided by linear features such as roads or power lines used to power human settlements. These structures can have important implications for wildlife populations as they may create barriers to movement for individuals. This can reduce the flow of genes and individuals across the landscape potentially increasing the risk of local extinctions for some populations. Our first objective in this study was to assess if greater prairie-chickens, a species of conservation concern in the Great Plains of North America, alter their movement behaviors (speed or direction of travel) or their selection patterns relative to linear features such as power lines, or roads using integrated step selection analysis (iSSA). Our second objective was to determine if changes in movement or selection behavior influenced the frequency at which greater prairie-chickens crossed linear structures. We assessed crossing rates by comparing the number of movements in observed greater prairie-chicken movement tracks that crossed these features to the number of movements that crossed these features in simulated movement tracks. Based on the iSSA analysis, we found that greater prairie-chickens avoided power lines, and roads in both seasons, but found little evidence for changes in speed or direction of travel at the population level. Further, prairie-chickens crossing roads and power lines at much lower rates than expected. Consistent avoidance of development in both seasons resulted in indirect habitat loss for greater prairie-chickens. Additionally, the avoidance of linear features has the potential to reduce connectivity across the landscapes. By considering both movement and selection we were able to develop a clearer picture of how increasing human activity may influence the space-use of species of conservation concern.

Lesser Prairie-Chicken Space Use Following Megafire in the Mixed-Grass Prairie
Nicholas Parker, Daniel Sullins, David Haukos, Kent Fricke, Christian Hagen

Fire was a key ecological driver in the formation of the Great Plains of North America and helped maintain diverse and heterogeneous grasslands benefiting grassland-dependent wildlife, such as the lesser prairie-chicken (Tympanuchus pallidicinctus). Decades of fire suppression in parts of the Great Plains has reduced species diversity and facilitated woody plant encroachment, further fragmenting remaining lesser prairie-chicken habitat. Fire suppression, combined with effects of climate change, has led to an increase in size and severity of wildfires in the Great Plains. While wildfires may benefit some aspects of lesser prairie-chicken habitat, fires of this size (>40,000 ha) and intensity have not been recorded in recent history and lesser prairie-chicken response to such fires in modern, fragmented grasslands is unknown. We compared space use and resource selection by lesser prairie-chickens marked with GPS transmitters in the mixed-grass prairie of Kansas before (2014-2016) and after (2018-2020) a 2017 wildfire (252,000 ha). We used Brownian bridge movement models to estimate 95% isopleth home ranges and found no difference in overall lesser prairie-chicken space use before (828 ± 110 ha) and after (719 ± 101 ha) the fire. However, home ranges included 5 times more percent cover of Conservation Reserve Program (CRP) fields after the fire compared to before, suggesting CRP/cropland landscapes with disjointed fire fuel availability can provide refuge during extreme events. Step selection revealed lesser prairie-chickens strongly avoided wooded areas before and after the fire, indicating that although we did see mortality of woody species, areas did not become available for use by lesser prairie-chickens. Furthermore, lesser prairie-chickens avoided burned areas post-fire, suggesting limited habitat availability post-fire and emigration from the study site. Our results point to the need for multiple management strategies (e.g. prescribed fire, CRP enrollment) to manage lesser prairie-chicken habitat and limit future megafires.

After the Dust Settles: Survival, Space Use, and Resource Selection of Translocated Lesser Prairie-Chickens
Elisabeth Teige, Liam Berigan, Carly Aulicky, David Haukos, Kent Fricke, Liza Rossi, Kraig Schultz, Jonathan Reitz

The lesser prairie-chicken (Tympanuchus pallidicinctus) has experienced severe population declines over the last century. The current lesser prairie-chicken range is limited to four ecoregions including Short-Grass Prairie/CRP, Mixed-Grass Prairie, Sand Shinnery Oak Prairie, and Sand Sagebrush Prairie. Although >70% of the current population occurs within the Mixed-Grass Prairie and Short-Grass Prairie/CRP ecoregions, the Sand Sagebrush Prairie of southwestern Kansas and southeastern Colorado historically supported the largest density, with estimates as high as 86,000 birds in the 1970s. By 2016, populations decreased 98% across the ecoregion, with only an estimated 1,479 birds remaining. To supplement this population, 411 lesser prairie-chickens (204 males and 207 females) were translocated during 2016-2019, from the Shortgrass/CRP Ecoregion of northwestern Kansas to the Cimarron and Comanche National Grasslands in Kansas and Colorado, respectfully, which provide ~224,000 ha of Sand Sagebrush Prairie habitat. We deployed 279 VHF collars from 2016-2019 and 115 SAT-PTT transmitters from 2018-2019 on translocated lesser prairie-chickens. Post dispersal, female breeding season survival was similar between native (0.52, 95% CI = 0.47-0.57) and translocated (0.45, 95% CI = 0.39-0.51) birds but differed during the nonbreeding season with native survival of 0.73 (95% CI = 0.66-0.78) and translocated of 0.50 (95% CI = 0.41-0.58). After dispersal, home range areas were comparable with ecoregion native populations but varied between sexes. Resource selection functions indicate translocated birds use Conservation Reserve Program (CRP) land more than what is available on the landscape. National Grassland use overall was low as most birds dispersed following release; however, Comanche was used more than Cimarron. The opportunity to study the survival, home range development, and resource selection of a translocated and native population provides a unique opportunity to assess translocations as a viable management tool for lesser prairie-chickens in the Sand Sagebrush Prairie Ecoregion.

Brood-Habitat Quality Predicts Lek Occurrence and Male Lek Attendance in Sharp-Tailed Grouse
Jonathan Lautenbach, Aaron Pratt, Jeffrey Beck

Understanding why leks occur at certain sites over others has important conservation implications, especially in lekking grouse species where habitat and population management centers on lek locations. The lek hotspot hypothesis predicts that leks will occur in areas more frequented by females and offers a theoretical framework to explore why leks occur where they do. To identify whether leks are placed in areas more likely to be frequented by female sharp-tailed grouse (Tympanuchus phasianellus), we evaluated habitat selection and quality (as modeled by nest, brood, and female winter survival) based on multiple vegetation and topographic metrics from locations of 213 VHF-marked female sharptails during nesting, brood-rearing, and winter in south-central Wyoming from 2017–2019. We then compared predicted habitat selection and quality across life-history stages to 24 known leks to evaluate whether habitat selection or quality influenced lek occurrence and male lek attendance. Lek locations and male lek attendance were best predicted by brood-rearing habitat quality within 400 and 800 m of leks, respectively, with an increasing proportion of high-quality brood-rearing habitat indicating a higher probability of lek occurrence (β = 2.5; 95% CI 1.4–3.9) and increased male lek attendance at (β = 11.5; 95% CI 4.5–18.4). Although nest, brood-rearing, and winter habitat selection and nesting and winter habitat quality were not the top models, they did predict lek occurrence, but not male lek attendance; these models showed that the probability of lek occurrence increased with increasing probability of selection or quality. Our results suggests that sharp-tailed grouse leks occur in areas with more abundant brood habitat surrounding them and that lek attendance increases in areas with greater production potential. Our results support monitoring sharp-tailed grouse populations by conducting lek surveys and suggest that population changes might be due to varied brood success.

Quantifying Population Drivers Using Historical Prairie Grouse Monitoring Data
Danielle Berger, Larkin A. Powell, John Carroll, Jeffrey Lusk

Population monitoring data collected by state and federal agencies provide a long-term record of abundance trends, but protocols are not explicitly designed to quantify drivers of those trends. Knowledge of population drivers is critical to the mechanistic understanding of population dynamics that underpins vital rate-focused conservation and management practices. However, longitudinal studies designed to address population drivers are rare. Historical monitoring data could potentially be leveraged to provide information on population drivers if combined with long-term data sets that describe environmental covariates at similar spatial and temporal scales. Greater prairie-chickens (Tympanuchus cupido pinnatus) and sharp-tailed grouse (Tympanuchus phasianellus jamesi) are both species of conservation concern because of drastic population declines throughout their respective ranges. In the Sandhills of Nebraska, the birds occupy shared range, necessitating co-management. Using sixty-four years or prairie grouse breeding ground count data combined with indices describing predation pressure, land use change and climate, we attempted to quantify drivers of species-specific population growth rates in the Sandhills. We used a Ricker population process model in a Bayesian state-space framework to explore the relationship between species-specific count data and environmental covariates with a one-year time lag. To draw out the covariates with the strongest influence on population trends, we used a variable selection technique. The top models for prairie-chickens and sharp-tailed grouse included different environmental covariates, suggesting that prairie grouse are subject to species-specific population drivers. Management strategies in shared range must address species-specific resource needs to ensure the persistence of both greater prairie-chickens and sharp-tailed grouse. Our study provides a framework for wildlife managers to use existing count-based monitoring records and free, publicly available environmental data to explore population drivers in addition to abundance trends.

Contributed Oral
Location: Virtual Date: November 2, 2021 Time: 3:00 pm - 4:00 pm