21 results on '"J. Derek Scasta"'
Search Results
2. Framing Contemporary U.S. Wild Horse and Burro Management Processes in a Dynamic Ecological, Sociological, and Political Environment
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J. Derek Scasta, Jacob D. Hennig, and Jeffrey L. Beck
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burro ,equus asinus ,equus ferus caballus ,feral horses ,human-wildlife conflicts ,management ,human dimensions ,policy ,public rangelands ,wild free-roaming horses and burros act ,Environmental sciences ,GE1-350 ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
The Wild Free-Roaming Horses and Burros Act (WFRHBA) of 1971 established all “unbranded or unclaimed” equids on U.S. public lands as “living symbols of the historic and pioneer spirit of the West.” Today, >72,000 feral horses (Equus ferus caballus) and burros (E . asinus ; WHB) live on western U.S. public rangelands. The number of WHBs exceeds the Bureau of Land Management’s maximum Appropriate Management Level (AML) of 26,715 by a factor of approximately 2.7 and has nearly doubled from 2007–2015. The AML was set to balance WHB numbers with rangeland health and support other uses such as wildlife habitat and livestock grazing. Thus, public land management agencies must manage WHB under the multiple-use context. This becomes more problematic when WHB populations go largely unmanaged and excessive equid grazing negatively impacts rangeland vegetation, native wildlife, and livestock forage. In addition, approximately 46,000 WHBs exist in off -range holding facilities, further straining federal budgets. Contemporary management actions are being constrained by: (1) litigation that has stymied federal government WFRHBA enforcement eff orts, (2) public emotional concerns that lack reconciliation with the current situation, and (3) increasing complexity in the laws and subsequent amendments shaping WHB management policy. Collectively, these factors impede the implementation of concrete solutions to restore AML. Consequently, stakeholders are increasing polarized over how WHBs are or should be managed. While the ecological and animal health and welfare implications of unmanaged WHB populations are somewhat understood, publicly acceptable strategies to maintain healthy populations, healthy and functioning rangelands, and multiple uses that sustain wildlife and local communities remain unresolved.
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- 2018
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3. Resource Selection of Free-ranging Horses Influenced by Fire in Northern Canada
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Sonja E. R. Leverkus, Samuel D. Fuhlendorf, Marten Geertsema, Brady W. Allred, Mark Gregory, Alexandre R. Bevington, David M. Engle, and J. Derek Scasta
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boreal forests ,canada ,equus ferus caballus ,fire ,guide outfitters ,horses ,pyric herbivory ,rangelands ,Environmental sciences ,GE1-350 ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
Free-ranging or feral horses (Equus ferus caballus) were important to the livelihood of First Nations and indigenous communities in Canada. The early inhabitants of the boreal region of British Columbia (BC) capitalized on naturally occurring wildfires and anthropogenic burning to provide forage for free-ranging horses and manage habitat for wildlife. This form of pyric herbivory, or grazing driven by fi re via the attraction to the palatable vegetation in recently burned areas, is an evolutionary disturbance process that occurs globally. However, its application to manage forage availability for free-ranging horses has not been studied in northern Canada. Across Canada, there are varying levels of governance for feral and free-ranging horses depending on the provincial jurisdiction and associated legislation. The BC Range Act (Act) allows range tenure holders to free-range horses that they own for commercial operations on Crown land. Big-game guide outfitters as range tenure holders are provided grazing licences or grazing permits under the Act with an approved range use plan. Guide outfitters and other range tenure holders have incorporated fi re ecology as part of their rangeland management in mountainous portions of the boreal forest of northeastern BC to promote mosaics of vegetation height and species composition across the landscape to meet nutritional requirements of their free-ranging horses. Using resource selection function models, we evaluated the influence of pyric herbivory on boreal vegetation and use by horse herds occupying 4 distinct landscapes. We found that horses preferentially selected recently burned areas and areas that burned more frequently when they were available. We also found that horses avoided steep slopes and forest cover types. Fire and the ecological processes associated with it, including pyric herbivory, are important considerations when managing boreal rangelands in northeastern BC. Because historical fi re regimes of the boreal region of Canada differ from the arid regions of the United States inhabited by feral horses, the role of pyric herbivory in altering horse distributions in the United States is limited.
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- 2018
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4. Spatial Ecology Observations From Feral Horses Equipped With Global Positioning System Transmitters
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Jacob D. Hennig, Jeffrey L. Beck, and J. Derek Scasta
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equus ferus caballus ,home range ,movement ,utilization distribution ,wyoming ,Environmental sciences ,GE1-350 ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
Our understanding of the spatial ecology of feral horses (Equus ferus caballus ) and burros (E . asinus ) in the United States is limited. Robust location data are needed to better understand the permeability of Bureau of Land Management Herd Management Area boundaries, relative to feral horse movement patterns and home ranges. To increase our understanding of feral horse movement, in February to March 2017, we deployed global positioning system (GPS) collars on 14 females ≥5 years old that were captured in the Adobe Town Herd Management Area (ATHMA) of southcentral Wyoming, USA. Herein, we report initial results from movement data collected during summer (May 15 to September 15) 2017 for 9 horses. We limited our focus to these 9 horses because we received at least 2 months of continuous GPS location data from them during summer 2017. Feral horse daily movement distances averaged 9.0 km (SE = 0.3), and mean summer total home range size was 40.4 km2 (SE = 6.7). Of GPS location fixes obtained, 44.9% were outside ATHMA and 10.8% were on private land. Our results highlight the types of data that GPS collars can provide and illustrate the difficulties of managing free-roaming species such as horses and burros on landscapes with heterogeneous sociopolitical patterns. Expanded use of such technology on feral horses and burros in the United States will yield greater insight on spatial complexities constraining management.
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- 2018
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5. Effects of telemetry collars on two free-roaming feral equid species.
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Kathryn A Schoenecker, Sarah R B King, Jacob D Hennig, Mary J Cole, J Derek Scasta, and Jeffrey L Beck
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Medicine ,Science - Abstract
There are two species of free-roaming feral equids in North America: horses (Equus caballus) and donkeys or "burros" (E. asinus). Both species were introduced as domestic animals to North America in the early 1500s and currently inhabit rangelands across the western United States, Canada, and all continents except Antarctica. Despite their global distribution, little is known about their fine scale spatial ecology. Contemporary research tools to assess space use include global positioning system (GPS) tracking collars, but older models were problematic due to stiff collar belting causing poor fit. We tested modern designs of GPS collars on n = 105 horses and n = 60 burros for 4 years in five populations (3 horse, 2 burro) across the western United States, to assess whether collars posed welfare risks to horses or burros. We found no difference in survival of collared versus uncollared mares and jennies, and no difference in survival of their foals. In 4036 of 4307 observations for horses (93.7%) and 2115 of 2258 observations for burros (93.6%), collars were observed symmetrical, maintaining proper fit on the neck. Fur effects from collars (sweaty neck, indented fur, broken fur) were seen in 3% of horse observations and 25% of burro observations. Superficial effects (chafes and marks on skin surface) were seen in 2% of horse observations and 11% of burro observations; no severe effects from collars were seen. Body condition was not affected by collars; mean body condition of collared horses was 4.70 ± 0.54 (mean ± s.d) and 4.71 ± 0.65 for collared burros. Behavior results indicated minimal effects; collared horses stood slightly more than uncollared, and collared burros stood and foraged more in one population, but not in the other. For 6.3% of observations of horses and 6.4% of observations of burros, we found an effect of time wearing a collar on the cumulative sum of fur effects which increased over time (burros: rs = 0.87, P =
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- 2024
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6. Movement Dynamics and Energy Expenditure of Yearling Steers Under Contrasting Grazing Management in Shortgrass Steppe
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Tamarah R. Jorns, Justin D. Derner, David J. Augustine, David D. Briske, Lauren M. Porensky, J. Derek Scasta, Jeffrey L. Beck, and Scott Lake
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Ecology ,Animal Science and Zoology ,Management, Monitoring, Policy and Law ,Nature and Landscape Conservation - Published
- 2022
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7. A crossroads in the rearview mirror: the state of United States feral equid management in 2023
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Jacob D Hennig, Courtney J Duchardt, Saeideh Esmaeili, Samuel D Fuhlendorf, Jeffrey L Beck, Tolani I Francisco, and J Derek Scasta
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General Agricultural and Biological Sciences - Published
- 2023
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8. Adaptive grazing management in semiarid rangelands: An outcome-driven focus
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Grady Grissom, Justin D. Derner, David J. Augustine, Emily Kachergis, J. Derek Scasta, Bob Budd, John P. Ritten, and Hailey Wilmer
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,Ecology ,Computer science ,business.industry ,Geography, Planning and Development ,Environmental resource management ,Context (language use) ,Management, Monitoring, Policy and Law ,01 natural sciences ,Outcome (game theory) ,Ecosystem services ,010601 ecology ,Watershed management ,Adaptive management ,Grazing ,Ecosystem ,Rangeland ,business ,0105 earth and related environmental sciences - Abstract
On the Ground • Adaptive management should explicitly involve stakeholders, emphasize multiple iterations of identifying and prioritizing outcomes, and tightly link science-informed monitoring to decision-making benchmarks for effective feedback loops. • Short-term monitoring procedures should be simple, quick, and based on consistent methods that are focused on locations where meaningful change is expected or uncertainty is high. • Long-term monitoring procedures should emphasize consistent methodology across years that provides broader ecosystem context for multiple ecosystem services (e.g., watershed protection and grassland bird habitat). • Incorporating timely feedback from monitoring improves the capacity for rapid decision-making when benchmarks are attained and management should be modified.
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- 2022
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9. Forum: Critical Decision Dates for Drought Management in Central and Northern Great Plains Rangelands
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Alexander J. Smart, Tonya Haigh, Justin D. Derner, Jerry D. Volesky, J. Derek Scasta, Miranda A. Meehan, Jeffrey C. Mosley, Kevin K. Sedivec, Keith R. Harmoney, Mitchel P. McClaran, Mitchell B. Stephenson, and Lance T. Vermeire
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Ecology ,Agroforestry ,Economic return ,Growing season ,Forage ,Management, Monitoring, Policy and Law ,Environmental resource ,Adaptive management ,Environmental science ,Animal Science and Zoology ,Ecosystem ,Precipitation ,Rangeland ,Nature and Landscape Conservation - Abstract
Ranchers and other land managers of central and northern Great Plains rangelands face recurrent droughts that negatively influence economic returns and environmental resources for ranching enterprises. Accurately estimating annual forage production and initiating drought decision-making actions proactively early in the growing season are both critical to minimize financial losses and degradation to rangeland soil and plant resources. Long-term forage production data sets from Alberta, Kansas, Montana, Nebraska, North Dakota, South Dakota, and Wyoming demonstrated that precipitation in April, May, and June (or some combination of these months) robustly predict annual forage production. Growth curves from clipping experiments and ecological site descriptions (ESDs) indicate that maximum monthly forage growth rates occur 1 mo after the best spring month (April to June) precipitation prediction variable. Key for rangeland managers is that the probability of receiving sufficient precipitation after 1 July to compensate for earlier spring precipitation deficits is extremely low. The complexity of human dimensions of drought decision-making necessitates that forage prediction tools account for uncertainty in matching animal demand to forage availability, and that continued advancements in remote sensing applications address both spatial and temporal relationships in forage production to inform critical decision dates for drought management in these rangeland ecosystems.
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- 2021
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10. Participant motivations for the Wyoming Prescribed Fire Council (PFC): Emergence from a regional void
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J. Derek Scasta and Ryan Wilbur
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,Ecology ,business.industry ,Prescribed burn ,Geography, Planning and Development ,Environmental resource management ,Management, Monitoring, Policy and Law ,01 natural sciences ,010601 ecology ,Geography ,Void (composites) ,business ,0105 earth and related environmental sciences - Abstract
On the Ground • Prescribed Fire Councils (PFCs) are different than Prescribed Burn Associations. • A regional void of PFCs exists in the northern Rockies and northern Great Plains. • We interviewed 14 founding members of the Wyoming PFC to understand their motivations. • Three themes were identified: 1) collaboration, 2) constraints, and 3) public perceptions. • There is a need for cross-boundary engagement and strategies for dealing with narrow burn windows.
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- 2021
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11. Disease and weather induce rapid shifts in a rangeland ecosystem mediated by a keystone species (Cynomys ludovicianus)
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Courtney J. Duchardt, David J. Augustine, Lauren M. Porensky, Jeffrey L. Beck, Jacob D. Hennig, David W. Pellatz, J. Derek Scasta, Lauren C. Connell, and Ana D. Davidson
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Ecology - Abstract
Habitat loss and changing climate have direct impacts on native species but can also interact with disease pathogens to influence wildlife communities. In the North American Great Plains, black-tailed prairie dogs (Cynomys ludovicianus) are a keystone species that create important grassland habitat for numerous species and serve as prey for predators, but lethal control driven by agricultural conflict has severely reduced their abundance. Novel disease dynamics caused by epizootic plague (Yersinia pestis) within prairie dog colonies have further reduced prairie dog abundances, in turn destabilizing associated wildlife communities. We capitalized on a natural experiment, collecting data on prairie dog distributions, vegetation structure, avian abundance, and mesocarnivore and ungulate occupancy before (2015-2017) and after (2018-2019) a plague event in northeastern Wyoming, USA. Plague decimated black-tailed prairie dog populations in what was then the largest extant colony complex, reducing colony cover in the focal area from more than 10,000 ha to less than 50 ha. We documented dramatic declines in mesocarnivore occupancy and raptor abundance post-plague, with probability of occupancy or abundance approaching zero in species that rely on prairie dogs for a high proportion of their diet (e.g., ferruginous hawk [Buteo regalis], American badger [Taxidea taxus], and swift fox [Vulpes velox]). Following the plague outbreak, abnormally high precipitation in 2018 hastened vegetation recovery from prairie dog disturbance on colonies in which constant herbivory had formerly maintained shortgrass structure necessary for certain colony-associates. As a result, we observed large shifts in avian communities on former prairie dog colonies, including near-disappearance of mountain plovers (Charadrius montanus) and increases in mid-grass associated songbirds (e.g., lark bunting [Calamospiza melanocorys]). Our research highlights how precipitation can interact with disease-induced loss of a keystone species to induce drastic and rapid shifts in wildlife communities. Although grassland taxa have co-evolved with high spatiotemporal variation, fragmentation of the remaining North American rangelands paired with higher-than-historical variability in climate and disease dynamics are likely to destabilize these systems in the future.
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- 2022
12. Ecological Sites: Can they be Managed to Promote Livestock Production?
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David J. Augustine, Hailey Wilmer, J. Derek Scasta, Tamarah Jorns, Lauren M. Porensky, Justin D. Derner, David D. Briske, María E. Fernández-Giménez, and Averi Q. Reynolds
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0106 biological sciences ,chemistry.chemical_classification ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Ecology ,Steppe ,Range (biology) ,business.industry ,animal diseases ,Geography, Planning and Development ,Growing season ,Forage ,Management, Monitoring, Policy and Law ,01 natural sciences ,010601 ecology ,chemistry ,Loam ,parasitic diseases ,Organic matter ,Livestock ,Precipitation ,business ,0105 earth and related environmental sciences - Abstract
On the Ground • We assessed diet quality and livestock weight gains for shortgrass steppe pastures dominated by Loamy Plains or Sandy Plains ecological sites. • When growing season precipitation is “normal,” livestock gains are higher on Sandy Plains ecological sites, and diet quality is not limiting livestock production. • Conversely, when growing season precipitation declines by ≥ 20%, digestible organic matter, but not crude protein, influences livestock gains. These negative effects on livestock gains are more pronounced for the Loamy Plains ecological site. • Pastures with multiple ecological sites may provide range managers greater forage diversity for livestock and higher livestock gains during dry growing seasons.
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- 2019
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13. Global Application of Prescribed Fire
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John R. Weir, J Derek Scasta, John R. Weir, and J Derek Scasta
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- Prescribed burning--Environmental aspects, Wildfires--Environmental aspects, Fire prevention, Forest fires--Prevention and control, Wilderness areas--Fire management, Prescribed burning, Wildfires--Prevention and control, Fire ecology, Fire risk assessment, Fire management
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Global Application of Prescribed Fire provides a first-hand perspective of the various methods and ways people around the world view and use prescribed fire. It covers the logistics, constraints and social dynamics surrounding the intentional use and application of fire by humans, and demonstrates how, why, when and where prescribed fire is used in different regions. Written by international experts, the book has four key objectives: explore new techniques, ideas and thoughts on how to apply prescribed fire from a global perspective; provide regional case studies covering issues that may constrain or enhance prescribed fire projects; stimulate cross-cultural conversations about how fires function in ecosystems; and relate prescribed fire to wildfire regimes with implications for protecting life and property, as well as sustaining local fire cultures and unique fire-dependent flora and fauna. Global Application of Prescribed Fire enhances our understanding and knowledge about the application of prescribed fire. This comprehensive book will provide fire practitioners, researchers, agencies and policymakers with key ecological and managerial insight of how prescribed fires are conducted around the globe.
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- 2022
14. Variation in sage-grouse habitat quality metrics across a gradient of feral horse use
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Jacob D. Hennig, J. Derek Scasta, Jeffrey L. Beck, and Courtney J. Duchardt
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0106 biological sciences ,Utilization distribution ,geography ,Equus ferus caballus ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Ecology ,Perennial plant ,Wildlife ,Biology ,010603 evolutionary biology ,01 natural sciences ,Arid ,Shrubland ,Habitat ,Grazing ,media_common.cataloged_instance ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences ,Earth-Surface Processes ,media_common - Abstract
Feral horse (Equus ferus caballus) grazing can alter arid shrubland habitat in the western United States to the detriment of sympatric wildlife species, including the greater sage-grouse (Centrocercus urophasianus). To date, studies of horse-influenced habitat alteration have only occurred in a few locations and have infrequently represented gradients of horse use. We investigated whether greater sage-grouse habitat quality metrics were negatively associated with feral horse use in southcentral Wyoming, USA. We also tested whether utilization distributions generated from feral horses tracked with global position system transmitters were correlated with dung pile density, our index of horse use. Dung pile density did not vary among utilization distribution levels, indicating utilization distributions were a poor predictor of cumulative horse use. Bare ground increased with dung pile density (β = 0.06, 85% CI = 0.04–0.18), and grass height exhibited a threshold response and began to decline after 638 piles/ha. Other habitat metrics including percent shrub cover, native perennial grass cover, and visual obstruction were better explained by topographic and temporal variation. Our results suggest that herd size reduction may limit soil erosion potential and improve desired herbaceous structure, though additional management actions regarding feral horse use are needed to sustain high-quality greater sage-grouse habitat.
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- 2021
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15. Vegetation Responses to Season of Fire in Tallgrass Prairie: A 13-Year Case Study
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John R. Weir and J. Derek Scasta
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0106 biological sciences ,Smoke ,010504 meteorology & atmospheric sciences ,Agroforestry ,Forestry ,Vegetation composition ,Vegetation ,Ecological succession ,Environmental Science (miscellaneous) ,Seasonality ,medicine.disease ,01 natural sciences ,010601 ecology ,Vegetation response ,medicine ,Environmental science ,Forb ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences ,Woody plant - Abstract
Fire regulates vegetation composition of fire-dependent grasslands in North American tallgrass prairies. We measured the vegetation response to prescribed fire seasonality by burning in two-month increments every two years, from 2004 to 2015, west of Stillwater, Oklahoma, USA. Fire exclusion or burning in any season led to an in increase in woody plant cover ranging from 18 % to 63 %, except for September through October, which showed no increase. Tallgrass cover increased with September through December burn treatments. Forb cover decreased with burning from January through April, but was highest in the September through October treatment. These vegetation responses suggest that land managers, policy makers, and researchers should consider the benefits of burning outside of the traditional late-winter to early-spring window, providing that they have the ability to increase the number of burn days and reduce temporal concentrations of smoke.
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- 2017
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16. Transboundary Animal Diseases (TADs) affecting domestic and wild African ungulates: African swine fever, foot and mouth disease, Rift Valley fever (1996-2018)
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Craig M. Calkins and J. Derek Scasta
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Livestock ,Rift Valley Fever ,040301 veterinary sciences ,Swine ,Pastoralism ,Arbovirus ,0403 veterinary science ,03 medical and health sciences ,medicine ,Animals ,Rift Valley fever ,Socioeconomics ,African Swine Fever ,030304 developmental biology ,0303 health sciences ,General Veterinary ,biology ,Foot-and-mouth disease ,business.industry ,Zoonosis ,Outbreak ,04 agricultural and veterinary sciences ,biology.organism_classification ,medicine.disease ,Tanzania ,Geography ,Foot-and-Mouth Disease ,Africa ,business - Abstract
Transboundary Animal Diseases (TADs) affecting ungulates are potentially epidemic diseases that are contagious or transmissible, and a concern for humans worldwide. While globalization has led to increased containment efforts at a global scale, additional local attention is needed as well for vulnerable pastoralist communities that are in close proximity to livestock. We reviewed and then summarized outbreaks, cases, and deaths for 3 TADs (African Swine Fever (ASF), Foot and Mouth Disease (FMD), and Rift Valley Fever (RVF)) affecting domestic and wild ungulates for all African countries from 1996 to 2018 by compiling data from two World Organization for Animal Health databases. For ASF, 22 countries had no data. Countries with the most ASF case were Benin, Democratic Republic of Congo, Madagascar, Malawi, and Nigeria. Greatest reported ASF cases in a year was Benin in 1997 (387,808), Madagascar in 1998 (153,229), and Democratic Republic of Congo in 2011 (112,775). For FMD, 10 countries had no data. Countries with the most FMD cases were Burkina Faso, Tanzania, Zambia, Ethiopia, and Benin. Greatest reported FMD cases in a year was Zambia in 2004 (150,000). For RVF, 34 countries had no data. Countries with the most RVF were Tanzania, South Africa, Rwanda, Mauritania, and Kenya. Greatest reported RVF cases in a single year was Tanzania in 2007 (32,128) and South Africa in 2010 (12,569). Our spatio-temporal summary of these TADs can inform global containment strategies and prioritize local education efforts. Combined, this review enhances global awareness of TAD trends while facilitating education at the local level to prevent the risk of animal-to-human zoonosis through animal handling and management decisions.
- Published
- 2019
17. Meta-Analysis of Diet Composition and Potential Conflict of Wild Horses with Livestock and Wild Ungulates on Western Rangelands of North America
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Catherine J. Angwin, J. Derek Scasta, and Jeffrey L. Beck
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0106 biological sciences ,Equus ferus caballus ,Ungulate ,Ecology ,biology ,business.industry ,Management, Monitoring, Policy and Law ,Odocoileus ,biology.organism_classification ,Graminoid ,010603 evolutionary biology ,01 natural sciences ,010601 ecology ,Wild horse ,Forb ,media_common.cataloged_instance ,Animal Science and Zoology ,Livestock ,business ,Ovis ,Nature and Landscape Conservation ,media_common - Abstract
Wild horse (Equus ferus caballus) management in western North America is an escalating concern for ecological integrity on these landscapes. Identifying potential diet overlap among horses, livestock, and wildlife will inform management decisions to optimize multiple interests. To understand dietary relationships, we conducted a quantitative synthesis of microhistological fecal studies for wild horse, beef cattle ( Bos spp.), domestic sheep (Ovis aries), elk (Cervus elaphus), pronghorn (Antilocapra americana), and mule deer (Odocoileus hemionus) diet composition on western rangelands of North America. Our search yielded 60 studies from 14 states, 1 Canadian province, and 2 Mexican states with 392 unique species-season samples. We summarized plant species into graminoid, forb, and browse functional groups. For wild horses, seasonal diet composition means for graminoids (77−89%), forbs (4−15%), and browse (3−10%) did not vary seasonally for any plant group ( P ≤ 0.05). Univariate analyses and the calculation of effect sizes corroborated our finding that graminoid composition explained the potential overlap of wild horses with cattle regardless of season, with sheep and elk in the spring, with sheep in the summer, and with elk in the fall and winter. Although data indicate wild horse diets are primarily composed of graminoids, several studies reported unusual, regionally specific shifts in response to winter snow that limited graminoid accessibility, leading to higher browse composition. Season, plant composition, and ungulate assemblage may all influence dietary competition between wild horses and other large ungulate sharing western North American rangelands; however, the low and nonsignificant heterogeneity values at alpha 0.01 for cattle:horse effect size comparisons suggest that cattle and horses respond to regional and seasonal variation similarly—a result not observed for other ungulate:horse comparisons. Our meta-analysis provides a robust data set for evaluations of diet composition for wild horses, livestock, and wildlife, whereas no empirical studies have assessed all species together.
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- 2016
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18. Drought Influences Control of Parasitic Flies of Cattle on Pastures Managed with Patch-Burn Grazing
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Samuel D. Fuhlendorf, Diane M. Debinski, Justin L. Talley, J. Derek Scasta, David M. Engle, and John R. Weir
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Integrated pest management ,Ecology ,biology ,Stable fly ,Economic threshold ,Stomoxys ,Management, Monitoring, Policy and Law ,biology.organism_classification ,Musca autumnalis ,Haematobia irritans ,Agronomy ,Grazing ,Animal Science and Zoology ,Rangeland ,Nature and Landscape Conservation - Abstract
We compared the influence of patch-burn grazing to traditional range management practices on abundance of the most economically injurious fly parasites of cattle. Horn flies (Haematobia irritans), face flies (Musca autumnalis), stable flies (Stomoxys calcitrans), and horse flies (Tabanus spp.) were assessed at study locations in Oklahoma and Iowa, USA, in 2012 and 2013. Experiments at both locations were spatially replicated three times on rangeland grazed by mature Angus cows. Grazing was year-long in Oklahoma and seasonal in Iowa from May to September. One-third of patch-burn pastures were burned annually, and traditionally managed pastures were burned completely in 2012 but not at all in 2013. Because of significant location effects, we analyzed locations separately with a mixed effects model. Horn flies and face flies were below economic thresholds with patch-burn grazing but at or above economic thresholds in unburned pastures in Iowa. Pastures in Iowa that were burned in their entirety had fewer horn flies but did not have fewer face flies when compared with no burning. There was no difference among treatments in horn fly or face fly abundance in Oklahoma pastures. Stable flies on both treatments at both locations never exceeded the economic threshold regardless of treatment. Minimizing hay feeding coupled with regular fire could maintain low stable fly infestations. Horse flies at both locations and face flies in Oklahoma were in such low abundance that treatment differences were difficult to detect or explain. The lack of a treatment effect in Oklahoma and variable year effects are the result of a drought year followed by a wet year, reducing the strength of feedbacks driving grazing behavior on pastures burned with patchy fires. Patch-burning or periodically burning entire pastures in mesic grasslands is a viable cultural method for managing some parasitic flies when drought is not a constraint.
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- 2015
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19. Systematic review of equids and telemetry collars: implications for deployment and reporting
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Jeffrey L. Beck, Jacob D. Hennig, Sarah R. B. King, J. Derek Scasta, and Kathryn A. Schoenecker
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Equus ferus caballus ,biology ,business.industry ,Ecology ,Antilocapra americana ,Management, Monitoring, Policy and Law ,Odocoileus ,biology.organism_classification ,biology.animal ,Telemetry ,Medicine ,media_common.cataloged_instance ,Injury risk ,Wildlife management ,business ,Animal species ,Cervus canadensis ,Ecology, Evolution, Behavior and Systematics ,Demography ,media_common - Abstract
Abstract Data from animals equipped with global positioning system collars have advanced our understanding of vertebrates, but this technology has rarely been employed to study feral equids. Hesitation to equip feral equids with telemetry collars in the USA can often be attributed to safety concerns stemming from one study from the 1980s, where injuries were sustained by feral horses (Equus ferus caballus) equipped with radio-collars. Improvements in collar design over the ensuing quarter-century may have decreased risk of collar-related complications; however, telemetry-based studies on feral equids continue to be limited. In the present review, studies from wild and feral equids worldwide were systematically reviewed to better understand the mortality and injury risk in application of telemetry collars to equids. Our goals were to: (1) report the number of individual equids fitted with telemetry collars (1979–2017); and (2) document the number of individual equids that reportedly died or suffered injuries from collars or other sources. A comparative review of elk (Cervus canadensis), mule deer (Odocoileus hemionus) and pronghorn (Antilocapra americana) was also conducted to evaluate the relative risk of collar-related complications among equids and routinely collared North American ungulates. In total, 1089 wild and feral telemetered equids were identified across 48 studies. Of these, 87 (8.0%) were reported to have died, with only one (0.09%) mortality attributable to a collar. Comparatively, 23.0% (1095) of 4761 elk, mule deer and pronghorn fitted with telemetry collars were found to have died in the same number of studies, though no mortalities were reported to be related to the collar. Although wild and feral equids did not experience increased natural mortality compared with the other ungulates, studies have not provided sufficient information to assess relative risk of collar-related complications. Explicit reporting and discussion of telemetry collar impacts in future publications of all animal species are recommended, especially equids, to improve understanding of how telemetry collars can affect study individuals.
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- 2020
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20. Combustion of Cattle Fecal Pats Ignited by Prescribed Fire
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J. D. Carlson, J. Derek Scasta, David M. Engle, and John R. Weir
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animal structures ,Ecology ,animal diseases ,Prescribed burn ,Fuel moisture content ,Fuel load ,Management, Monitoring, Policy and Law ,Combustion ,body regions ,fluids and secretions ,Animal science ,Grazing ,cardiovascular system ,Environmental science ,Animal Science and Zoology ,Feces ,Nature and Landscape Conservation - Abstract
Cattle fecal pats readily ignite, are a common source of spot fires, and release extreme amounts of energy when burning. Moreover, dung-dependent livestock parasites can be reduced by combusting fecal pats in prescribed burns. We conducted a study to identify factors that influence combustion of cattle fecal pats. Fifty fecal pats were located in each burn unit before 10 prescribed fires and then rated for combustion after each fire. Combustion of cattle fecal pats was highly variable across fires, with average proportion of combustion of individual pats from the 10 fires ranging from 2 ± 2 to 98 ± 1% (mean ± SE). Of 10 fecal pat, fuel, and weather variables assessed, only fecal pat condition, 10-h time-lag dead fuel moisture (DFM), and fuel load entered as variables in a stepwise selection method of constructing a multiple regression model of combustion of fecal pats ( R 2 = 0.94, P s 0.01). Condition of fecal pats (a function of elapsed time since deposition, fuel moisture, and decomposition) explained the greatest variation of pat combustion (partial R 2 = 0.75), followed by 10-h DFM (partial R 2 = 0.12) and fuel load (partial R 2 = 0.07). Combustion was s 10% when 10-h DFM exceeded 13% regardless of pat condition. For every 1 Mg · ha -1 increase in fuel load, combustion of older and drier fecal pats increased by about 7%, but combustion of fresh fecal pats always averaged s 20% and was unrelated to fuel load. Our results demonstrate that combustion of pats can be managed to meet a variety of ecological and production goals.
- Published
- 2014
- Full Text
- View/download PDF
21. Ignition and fire behaviour of Juniperus virginiana in response to live fuel moisture and fire temperature in the southern Great Plains
- Author
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John R. Weir and J. Derek Scasta
- Subjects
Ecology ,Fire regime ,Meteorology ,Forestry ,Vegetation ,Combustion ,Atmospheric sciences ,Juniperus virginiana ,law.invention ,Ignition system ,Fire control ,Combustibility ,Boreal ,law ,Environmental science - Abstract
Fire is the most effective tool for managing Juniperus virginiana encroachment and associated fire risk, but its application has been limited. In a laboratory experiment we assessed a critical knowledge gap: how fire temperature and live fuel moisture (LFM) influences ignitability, sustainability, combustibility and consumability of J. virginiana. Percentage occurrence of ignition rose as fire temperature increased. The time to ignition increased while the occurrence of ignition decreased with increasing LFM. LFM and fire temperature each had a significant effect on all measured dependent variables (P≤0.05) as was their interaction, except in the case of sustainability. As expected, time to flaming was shortest and flame lengths were the highest under the hottest fire and lowest LFM scenarios. Flame heights increased quadratically as LFM decreased with a critical threshold at 60% LFM. Land managers can select burning prescriptions based on the interaction between fire temperature and LFM to either increase J. virginiana ignition or reduce hazards. In this study, the low and moderate fire temperatures were similar to those of prescribed fires at low and high fuel loads and the high temperature level mimics conditions found in extreme wildfires. Thus, higher fuel loads and hotter fires are required to maximise efficacy of fires targeting J. virginiana control.
- Published
- 2014
- Full Text
- View/download PDF
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