Response of Greater Sage-grouse to Sagebrush Reduction Treatments in Wyoming Big Sagebrush
Response of Greater Sage-grouse to Sagebrush Reduction Treatments in Wyoming Big Sagebrush

Author: Kurt T. Smith

Publisher:

Published: 2023

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

Vegetation treatments have been widely implemented in efforts to enhance conditions for wildlife populations. Yet the effectiveness of such efforts often lack rigorous evaluations to determine whether these practices are effective for targeted species. This is particularly important when manipulating wildlife habitats in ecosystems that are faced with multiple stressors. The sagebrush (Artemisia spp.) ecosystem has been altered extensively over the last century leading to declines of many associated species. Wyoming big sagebrush (A. tridentata wyomingensis) is the most widely distributed subspecies, providing important habitats for sagebrush-obligate and associated wildlife. Sagebrush often has been treated with chemicals, mechanical treatments, and prescribed burning to increase herbaceous forage species released from competition with sagebrush overstory. Despite many studies documenting negative effects of sagebrush control on greater sage-grouse (Centrocercus urophasianus) habitat, treatments are still proposed as a means of improving habitat for sage-grouse and other sagebrush-dependent species. Furthermore, most studies have focused on vegetation response and none have rigorously evaluated the direct influence of these treatments on sage-grouse. We initiated a 9-year (2011–2019) experimental study in central Wyoming, USA, to better understand how greater sage-grouse respond to sagebrush reduction treatments in Wyoming big sagebrush communities. We evaluated the influence of 2 common sagebrush treatments on greater sage-grouse demography and resource selection. We implemented mowing and tebuthiuron application in winter and spring 2014 and evaluated the pre- (2011–2013) and post-treatment (2014–2019) responses of sage-grouse relative to these management actions. We evaluated responses to treatments using demographic and behavioral data collected from 620 radio-marked female greater sage-grouse. Our specific objectives were to evaluate how treatments influenced 1) sage-grouse reproductive success and female survival; 2) sage-grouse nesting, brood-rearing, and female resource selection; 3) vegetation responses; and 4) forbs and invertebrates. Our results generally suggested neutral demographic responses and slight avoidance by greater sage-grouse in response to Wyoming big sagebrush treated by mowing and tebuthiuron. Neither mowing nor tebuthiuron treatments influenced nest survival, brood survival, or female survival. Selection for nest and brood-rearing sites did not differ before and after treatments. Females selected habitats near treatments before and after they were implemented; however, the strength of selection was lower after treatments compared with pre-treatment periods, which may be explained by a lack of response in vegetation and invertebrates following treatments. Perennial grass cover and height varied temporally yet did not vary systematically between treatment and control plots. Forb cover and species richness varied annually but not in relation to either treatment type. Perennial grass cover and height, forb cover, and forb species richness did not increase within mowed or tebuthiuron-treated areas that received 2 or 6 years of grazing rest compared with areas that received no grazing rest. Finally, forb and invertebrate dry mass did not differ between treated plots and control plots at mowing or tebuthiuron sites in any years following treatments. Results from our study add to a large body of evidence that sage-grouse using Wyoming big sagebrush vegetation communities do not respond positively to sagebrush manipulation treatments. Management practices that focus on the maintenance of large, undisturbed tracts of sagebrush will best facilitate the persistence of sage-grouse populations and other species reliant on the sagebrush steppe.

Habitat Selection and Short-term Demographic Response of Greater Sage-grouse to Habitat Treatments in Wyoming Big Sagebrush
Habitat Selection and Short-term Demographic Response of Greater Sage-grouse to Habitat Treatments in Wyoming Big Sagebrush

Author: Jason R. LeVan

Publisher:

Published: 2018

Total Pages: 107

ISBN-13: 9780438880306

DOWNLOAD EBOOK

Long-term declines in greater sage-grouse (Centrocercus urophasianus; hereafter ‘sage-grouse’) populations have captured the attention of land and wildlife managers. Fragmentation and loss of large, continuous sagebrush (Artemisia spp.) habitats is considered the leading cause of decreased populations of sage-grouse throughout their entire range. In response, managers in many areas have implemented small sagebrush reduction treatments to improve habitat conditions for brood-rearing sage-grouse. As such, a large body of research has focused on vegetative responses, and, to a lesser degree, wildlife-population responses to sagebrush habitat manipulations. Some research has shown potential benefits of habitat treatments to sage-grouse in mountain big sagebrush (A. tridentata vaseyana). Although vegetation in Wyoming big sagebrush (A. t. wyomingensis) responds differently than in mountain big sagebrush following reduction treatments, the response of sage-grouse to treatments in mountain or Wyoming big sagebrush communities has not been thoroughly investigated. The purpose of my thesis was to evaluate habitat selection and short-term (4 years since treatment) demographic response by sage-grouse to treatments in Wyoming big sagebrush habitats. My study was the first to evaluate both short-term demographic responses and habitat selection of sage-grouse to mowing and tebuthiuron treatments in Wyoming big sagebrush habitats. I conducted my research by using pre- and post-treatment data from n = 512 radio-marked female sage-grouse over a 7-year period (2011–2017) within the 4,595 km2 Jeffrey City study area in central Wyoming, USA. My study employed a Before-After Control-Impact design with 3 years of pre-treatment (2011–2013) and 4 years of post-treatment (2014–2017) data to evaluate sage-grouse responses. Mowing and tebuthiuron treatments were implemented in mosaic patterns replicated across 2 study areas each nested within our larger study area during winter and spring 2014, respectively. Mowing reduced canopy cover to ∼25.4 cm and tebuthiuron treatments were applied at a rate of 0.22 kg/ha active ingredient to achieve 50% sagebrush kill. Two remaining nested study areas served as offsite untreated control areas. Our primary objective for Chapter 2 was to identify how treatments influenced habitat selection of female sage-grouse during nesting, brood-rearing, and broodless periods. We found nesting, brood-rearing, and broodless sage-grouse selected for mowing and tebuthiuron treatment areas before and after treatment; however, a before-after treatment interaction suggested selection did not differ or was less strong after treatments. The primary objective for Chapter 3 was to assess the short-term demographic response of sage-grouse to treatments in Wyoming big sagebrush. We did not detect a before-after impact of sagebrush treatments on sage-grouse nest success, brood success, or adult female survival. The results of my thesis research suggest that treating Wyoming big sagebrush may not increase the habitat quality of Wyoming big sagebrush for sage-grouse. This suggests managers should assess the need and predicted success of sagebrush reduction treatments in Wyoming big sagebrush that are intended to enhance habitat conditions for breeding sage-grouse.

Identifying Habitat Quality and Population Response of Greater Sage-grouse to Treated Wyoming Big Sagebrush Habitats
Identifying Habitat Quality and Population Response of Greater Sage-grouse to Treated Wyoming Big Sagebrush Habitats

Author: Kurt T. Smith

Publisher:

Published: 2016

Total Pages: 169

ISBN-13: 9781369720563

DOWNLOAD EBOOK

Prioritizing and conserving habitat quality is crucial for maintaining viable wildlife populations, particularly for species of conservation concern such as the greater sage-grouse (Centrocercus urophasianus). Sage-grouse have experienced widespread population declines across much of their historic range, necessitating an understanding of how to maintain or improve the quality of remaining habitats that support their populations. Habitat loss and fragmentation is a major factor contributing to sage-grouse population declines and maintaining or improving remaining habitats has been thought to increase the value of important habitats for sage-grouse. The aim of my dissertation was to evaluate the influence of habitat management practices on sage-grouse at the population level and then explore potential mechanisms that may explain how populations are influenced by management to develop an understanding of the overall demographic response of sage-grouse to habitat treatments in big sagebrush (Artemisia spp.) communities in Wyoming. My dissertation is presented in four journal-formatted chapters. The objectives of Chapter 2 were to identify how treatments influenced annual growth rates in sage-grouse populations using yearly male sage-grouse lek counts within Sage-Grouse Management Zone II in Wyoming’s Core Areas from 1994 to 2012. One of the major findings of Chapter 2 was that mechanical sagebrush restoration treatments within 10 km of leks were negatively associated with annual greater sage-grouse population growth rates. This chapter is formatted for Restoration Ecology with co-author Jeffrey L. Beck. The primary objective of Chapter 3 was to evaluate how microhabitat use differed between reproductive states (brood-rearing versus broodless females) and if there were differences in summer survival between these states. Findings suggested that broodless females were roosting and foraging in concealed habitats with greater visual obstruction but less food forb availability. In contrast, brood-rearing females likely selected riskier microhabitats with less shrub cover and greater herbaceous understory as a tradeoff to predictably maximize foraging opportunities and promote growth and survival of their chicks. Chapter 3 is in revision in Wildlife Research with co-authors Jeffrey L. Beck and Christopher P. Kirol. The objective of Chapter 4 was to identify how mowing and tebuthiuron (Spike® 20P, Dow Agrosciences, Indianapolis, IN) treatments intended to reduce sagebrush canopy cover influenced the dietary quality of Wyoming big sagebrush in central Wyoming. Results from this chapter suggested that mowing and tebuthiuron treatments may slightly increase crude protein concentrations directly after treatments without immediate changes in plant secondary metabolites. This chapter is formatted for submission to Rangeland Ecology and Management. Chapter 5 evaluated whether diet availability and dietary consumption were predictive of sage-grouse chick body condition and if mowing and tebuthiuron treatments influenced the availability of insect and forb dietary resources for juvenile sage-grouse. Findings from this chapter suggest that females with broods selected habitats with diet resources in proportion to their availability, and dietary consumption by chicks was unrelated to available foods at brood-rearing locations. Chicks that consumed proportionally more plants during their first week of life tended to weigh more and have longer wing chords 5 weeks after hatch. Treated big sagebrush habitats contained forb and insect abundances that did not differ from untreated habitats and were equal to or less than habitats used by brood-rearing females. Chapter 5 is formatted for Journal of Wildlife Management with co-authors Jeffrey L. Beck, Aaron C. Pratt, and Jason R. LeVan.

Greater Sage-grouse (Centrocercus Urophasianus) Habitat Response to Mowing and Prescribed Burning Wyoming Big Sagebrush and Influence of Disturbance Factors on Lek Persistence in the Bighorn Basin, Wyoming
Greater Sage-grouse (Centrocercus Urophasianus) Habitat Response to Mowing and Prescribed Burning Wyoming Big Sagebrush and Influence of Disturbance Factors on Lek Persistence in the Bighorn Basin, Wyoming

Author: Jennifer E. Hess

Publisher:

Published: 2011

Total Pages: 152

ISBN-13: 9781124705446

DOWNLOAD EBOOK

My thesis work focused on evaluating the relative influence of prescribed burning (1990-1999 and 2000-2006) and mowing (2000-2006) treatments on the quality of greater sage-grouse (Centrocercus urophasianus) nesting and early brood-rearing habitats and landscape characteristics that influenced sage-grouse lek persistence from 1980 to 2009 in the Bighorn Basin of north-central Wyoming. Objectives of treatments have focused on land health, watershed improvement, and to enhance habitat conditions for livestock, greater sage-grouse (Centrocercus urophasianus), and other wildlife. I focused on how prescribed burning and mowing may affect sage-grouse nesting and early brood-rearing habitats by evaluating habitat quality through insect, soil, and vegetation parameters at 30 treated sites compared to 30 nearby, untreated reference sites. My sites were classified by treatment type, soil type, season, and decade of treatment (sites burned in the 1990s and sites burned or mowed during 2000-2006). Prescribed burning greatly ( -85.1 to -100%) reduced levels of sagebrush canopy cover at least 19 years postburn, while mowing maintained minimum levels of sagebrush canopy cover recommended for sage-grouse nesting and early brood-rearing habitats. In some cases, prescribed burning showed positive results for sage-grouse nesting and early brood-rearing habitats compared to mowing such as 6.3- to 16.9-times greater ant weights (mg/trap; on aridic burns during 1990s and ustic burns during 2000-2006 respectively), 2.3- to 85.1-times greater beetle weights (mg/trap) on ustic soils, 3.6- to 4.3-times higher perennial grass canopy cover on aridic soils, 2.6-times higher plant species richness on aridic soils during 2000-2006 burns, and 2.0- to 5.0-times higher soil nitrogen on burns during 2000-2006, but all of these characteristics were not found to be enhanced compared to reference sites. Mowing provided 3.6- to 13.2-times higher sagebrush canopy cover on ustic soils, 2.2- to 3.0-times higher sagebrush heights on aridic and ustic soils, and 1.2- to 1.5-times higher insect diversity on ustic and aridic soils than prescribed burning. When comparing mowed sites to reference sites, there was1.2- to 2.5-times higher litter and 3.5- to 9.1-times higher ant weights (mg/trap) at mowed sites. However, mowing did not promote an increase in other sage-grouse early brood-rearing needs such as the abundance of food forbs, abundance or weights of beetles and grasshoppers, or perennial grass canopy cover or height. Forb nutritional content and production were not enhanced (i.e., similar to reference sites) by either treatment. Perennial grass height and canopy cover (5 of 6 cases) were not enhanced through burning or mowing. The main benefit from prescribed burning was an increase in grasshopper abundance (no./trap) compared to reference sites (grasshopper abundance was 2.4- to 3.4-times greater at prescribed burned sites than reference sites). In general, results indicate few positive aspects of treating Wyoming big sagebrush to enhance habitat conditions for nesting and early brood-rearing sage-grouse as much as 19 years after prescribed burning and 9 years after mowing in the Bighorn Basin. Mowing, however, appears to be a better alternative than prescribed burning Wyoming big sagebrush, largely because it leaves intact sagebrush, but comparisons between reference sites typically did not suggest habitat conditions were enhanced through mowing. Consequently, managers contemplating these 2 treatment techniques to enhance sage-grouse habitats should consider other treatment strategies including non-treatment. When evaluating factors that may have influenced the probability of sage-grouse lek persistence in the Bighorn Basin I found support for the synergistic influence of multiple disturbance factors influencing sage-grouse lek persistence. I predicted that increasing roads, energy development, and wildfire will result in loss of more sage-grouse leks in the Bighorn Basin. The Bighorn Basin has lower developed reserves of oil and gas than many other regions of Wyoming; however, my study supports findings from studies in those areas that demonstrate energy development negatively affects lek persistence. I recommend that conservation efforts should focus on minimizing well development and implementing wildfire suppression tactics within 1.6-km of active sage-grouse leks.

Greater Sage-grouse Response to Sagebrush Manipulations in Rich County, Utah
Greater Sage-grouse Response to Sagebrush Manipulations in Rich County, Utah

Author: Roger Blair Stringham

Publisher:

Published: 2010

Total Pages: 108

ISBN-13:

DOWNLOAD EBOOK

Management of greater sage-grouse (Centrocercus urophasianus) in the west has changed over the last several decades in response to environmental and anthropogenic causes. Many land and wildlife management agencies have begun manipulating sagebrush with herbicides, machinery, and fire. The intent of these manipulations (treatments) is to reduce sagebrush canopy cover and increase the density of grass and forb species, thus providing higher quality sage-grouse brood-rearing habitat. However, monitoring of sage-grouse response to such manipulations has often been lacking or non-existent. The objective of our study was to determine the response of sage-grouse to sagebrush reduction treatments that have occurred recently in Rich County, Utah. Our study areas were treated with a pasture aerator with the intent of creating sage-grouse brood-rearing habitat. We used pellet transects, occupancy sampling, and GPS radio telemetry to quantify sage-grouse habitat use in treated and untreated areas. Pellet transect, occupancy, and GPS radio telemetry methods all showed a strong pattern of sage-grouse use of treated sites during the breeding and early brood-rearing periods. Sage-grouse use of treated sites was greatest in lower elevation habitat (1950 to 2110 m), and use was highest during the breeding and early brood-rearing periods. We found very little use of higher elevation (2120 to 2250 m) treated or untreated sites. Our results suggest that sagebrush reduction treatments can have positive impacts on sage-grouse use at lower elevations and can be successful in creating brood-rearing habitat. Elevation differences and period of sage-grouse use were significant factors in our study in determining how beneficial sagebrush reduction treatments were for sage-grouse.

Vegetation Response of a Wyoming Big Sagebrush (Artemisia Tridentata Ssp. Wyomingensis) Community to 6 Mechanical Treatments in Rich County, Utah
Vegetation Response of a Wyoming Big Sagebrush (Artemisia Tridentata Ssp. Wyomingensis) Community to 6 Mechanical Treatments in Rich County, Utah

Author: Daniel David Summers

Publisher:

Published: 2005

Total Pages: 62

ISBN-13:

DOWNLOAD EBOOK

In recent years, the importance of sagebrush to shrub-steppe ecosystems and associated plant and animal species has been recognized. The historical removal of herbaceous species by excessive and uncontrolled livestock grazing on many of our sagebrush ecosystems has resulted in a stagnant state where dense, competitive stands of sagebrush prevent herbaceous species from recovering. Most early research on sagebrush control was directed toward eradication to increase herbaceous forage for livestock production, rather than sagebrush thinning to improve shrub vigor and understory production for wildlife habitat and community diversity. Mechanical treatments have the ability to retain shrub and herbaceous components, while improving diversity within degraded sagebrush communities. This study evaluated the effects of 6 mechanical treatments and revegetation of a Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) community in northern Utah that were treated in the fall of 2001 and spring of 2002 (aerator only). Disking and imprinting killed 98% of the sagebrush and significantly (p

Greater Sage-Grouse
Greater Sage-Grouse

Author: Steve Knick

Publisher: Univ of California Press

Published: 2011-05-19

Total Pages: 665

ISBN-13: 0520948688

DOWNLOAD EBOOK

Admired for its elaborate breeding displays and treasured as a game bird, the Greater Sage-Grouse is a charismatic symbol of the broad open spaces in western North America. Unfortunately these birds have declined across much of their range—which stretches across 11 western states and reaches into Canada—mostly due to loss of critical sagebrush habitat. Today the Greater Sage-Grouse is at the center of a complex conservation challenge. This multifaceted volume, an important foundation for developing conservation strategies and actions, provides a comprehensive synthesis of scientific information on the biology and ecology of the Greater Sage-Grouse. Bringing together the experience of thirty-eight researchers, it describes the bird’s population trends, its sagebrush habitat, and potential limitations to conservation, including the effects of rangeland fire, climate change, invasive plants, disease, and land uses such as energy development, grazing, and agriculture.

Conservation of Greater Sage-grouse on Public Lands in the Western U.S.
Conservation of Greater Sage-grouse on Public Lands in the Western U.S.

Author: Carl L. Wambold

Publisher:

Published: 2002

Total Pages: 92

ISBN-13:

DOWNLOAD EBOOK

"Our general objective is to identify a set of short-run (three to five years) policy alternatives that are based on a synthesis of empirical research into the needs of the greater sage-grouse(Centrocercus urophasianus) and its relationship to the sagebrush system. In other words, based on what we know from research, we try to identify the best set of policy alternatives for maintaining and increasing sage-grouse populations on public lands that policy makers could implement and expect some results within a three- to five-year time frame"--Page 1

Greater Sage-grouse Reproductive Ecology and Response to Experimental Management of Mountain Big Sagebrush on Parker Mountain, Utah
Greater Sage-grouse Reproductive Ecology and Response to Experimental Management of Mountain Big Sagebrush on Parker Mountain, Utah

Author: David Kimball Dahlgren

Publisher:

Published: 2006

Total Pages: 117

ISBN-13: 9781109792614

DOWNLOAD EBOOK

I evaluated the effects of 2 mechanical treatments that may be used to manage greater sage-grouse (C. urophasianus) habitat. Dixie harrow and Lawson aerator treatments were conducted in replicated plots that contained (> 38% canopy cover) stands of mountain big sagebrush ( Artemisia tridentata vaseyana). I monitored shrub and herbaceous vegetation response. Both treatments effectively reduced shrub canopy to guidelines for sage-grouse brood-rearing habitat (10-25%). Dixie harrow responded with an increase in herbaceous cover. Additionally, I added Tebuthiuron plots and monitored sage-grouse use within all plots. Sage-grouse, and broods specifically, preferred Tebuthiuron plots compared to mechanical or control. I monitored sage-grouse hens during their reproductive efforts in 2003 and 2004 (n = 25 and 9, respectively). In 2003 and 2004, nest initiation rates were 95% and 56%, nest success was 50% and 80%, and mortality was 36% and 22%, respectively. Brood sites exhibited 20.1% shrub and 16.5% herbaceous cover.

Prescribed Fire Effects on Vegetation and Arthropod Dynamics, and Sampling Techniques in a Wyoming Big Sagebrush Community
Prescribed Fire Effects on Vegetation and Arthropod Dynamics, and Sampling Techniques in a Wyoming Big Sagebrush Community

Author: Edward C. Rhodes

Publisher:

Published: 2006

Total Pages: 258

ISBN-13:

DOWNLOAD EBOOK

In the western United States, sagebrush (Artemisia spp L.) dominated rangelands are extensive, accounting for approximately 63 million ha. The Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young) alliance is found in more xeric environments, occupying the largest area of the big sagebrush complex in areas within a 200-300mm precipitation zone at elevations ranging from 610-2130m. Wyoming big sagebrush communities provide habitat for nearly 100 bird and 70 mammal species throughout its range. A species that is of particular concern is the sage grouse (Centrocercus urophasianus Bonaparte), which depends on big sagebrush associations for food, nesting and cover. Much of its historical range has Redacted for privacy Redacted for privacy dwindled, prompting increasing scrutiny on land use and management throughout the big sagebrush association. Destruction of remaining habitat and the danger of invasion by annual grasses such as cheatgrass (Bromus tectorum L.), has necessitated the assessment of the effects of disturbance such as fire on these communities. This study was designed to: (A) determine the effects of prescribed fire on vegetation characteristics, (B) analyze the specific response of forbs and arthropods that are important in the diet of sage grouse to fire, and (C) compare the Modified- Whittaker and Daubenmire methods of estimating species richness and vegetation cover in a Wyoming big sagebrush community. In the first project, prescribed fire had little effect on herbaceous density, cover, or species richness, but did increase perennial grass and total herbaceous standing crop the second and third year post burn, and annual forb standing crop the first and second year. Big sagebrush and total shrub cover and density were greatly reduced in burned treatments. Green rabbitbrush cover was greater in unburned treatments, but no change in density was noted. Burning did not affect soil water availability. The second project showed little overall benefit to perennial forbs preferred by sage grouse, however there was a short-lived increase in Microsteris/Collinsia parviflora (Lindl.) cover in the second post burn year. Prescribed fire may be detrimental to Hymenoptera abundance. Orthoptera may benefit from prescribed fire, but further exploration is needed in that area. Annual exotic species richness was not shown to increase in either sampling method or treatment in the third project. This is important, as it shows that sites which are dominated by a large proportion of native species from various functional groups can resist invasion. There was no clear-cut delineation between the Modified-Whittaker and Daubenmire methods. While there were some similarities in the data between the two, the Modified-Whittaker method had substantially different percent cover estimations for perennial grass and total herbaceous components in 2005. The Modified-Whittaker method also did not detect treatment effects for biotic crust, bare ground/rock, and litter cover measurements that were seen with the Daubenmire method. Shrub cover measurements were similar in both methods. Further investigation is warranted to test the applicability of the Modified- Whittaker design.