Patterns of nest survival, movement and habitat use of sagebrush-obligate birds in an energy development landscape

The sagebrush ecosystem in western North America provides habitat for approximately 350 plant and animal species, many of which are species of conservation concern. The sage-grouse and several species of sagebrush associated songbirds have undergone population declines over the last fifty years. Energy development has been identified as one of the leading causes of sagebrush landcover loss and fragmentation and has contributed to declines of sagebrush dependent bird species. Our research represented management-oriented science related to the conservation of sagebrush associated species. We used a sagebrush-obligate songbird, the Brewer’s sparrow (Spizella breweri breweri), and the greater sage-grouse (Centrocercus urophasianus, hereafter sage-grouse) to address questions related to habitat selection, space use, reproductive rates and movements in an established energy field in the Powder River Basin (PRB) in Wyoming, USA. Attaching global positioning system (GPS) tags to wildlife can provide a tremendous amount of information that can be used to better understand many aspects of a species’ ecology and how wildlife may be responding to anthropogenic disturbances. Information gathered from tracking wildlife is critical to inform management and conservation actions designed to benefit species that are being effected by anthropogenic activities. To minimize impacts and increase capturing efficiency when capturing sage-grouse to attach GPS tags, we developed a new mobile capturing technique. We had a 71% capture success rate. The capturing method we describe proved effective in our study and we believe this method can be applied to other bird species with similar behavioral traits. For most wildlife species, researchers must select between multiple tracking technologies that represent trade-offs among data requirements, mass, and cost. Options tend to be more limited for smaller species and those that fly. To address our research question, we developed and tested a unique combination of a store-on-board GPS logger with an independent very-high-frequency (VHF) tag (hereafter hybrid tag) fitted on sage-grouse with a modified harness design. We compared the hybrid tag we designed with other tracking technologies commonly used in bird research, namely VHF and Argos satellite relay tags. Given our research objectives, that required both frequent location data and field-based observational data, we found hybrid tags were the most cost-effective option and capable of collecting more location data compared with Argos tags because of power savings associated with data transmission. Cost savings allowed us to avoid sacrificing sample size while still obtaining high-resolution location data in addition to field-based observational data such as the presence of sage-grouse chicks. We believe our hybrid tags and harness design would be beneficial to research on other bird species of comparable size to sage-grouse and those that are relatively localized year-round, including many other Galliformes. Habitat selection in wildlife occurs across multiples spatial scales from selection for broad geographic areas to fine-scale habitat components. Therefore, the selection scale of interest in a study must dictate the spatial extent of the area considered as available to the species and availability should be based on biologically realistic movements of that species or individual. Habitat selection studies are usually conducted at a population level. Habitat selection analyses at an individual level can reveal patterns in selection that are not apparent when using population-level approaches. The hybrid tag, that allowed for gathering high-resolution location and movement data, and new data analyses approaches allowed us to explore individual-level movements, space use (e.g., home ranges) and habitat selection of female sage-grouse that raised chicks (brood-rearing sage-grouse) in a coal-bed natural gas (CBNG) development area. We used integrated step selection analysis (iSSA) that permit the quantification of the effects of environmental and anthropogenic covariates on the movement and selection process simultaneously to evaluate habitat selection and avoidance behaviors. On average, brood-rearing female sage-grouse established home ranges in areas with a majority of the home range comprised of sagebrush landcover (mean = 77.4%) and a minimal proportion of the area comprised of anthropogenic surface disturbance (mean = 3.5%). Individual-level selection analyses helped us uncouple some aspects of energy development that influence habitat selection that likely would not have been detected at broader spatial scales. Brood-rearing females consistently selected for natural vegetation and avoided disturbed surfaces, including reclamation surfaces, at fine spatial scales. Power line visibility generally led to avoidance behavior; however, much shorter (3m) CBNG well structures generally did not. We found that individual variability was partially explained by age (adult or first year), or previous experience of the landscape. Our results do not support individual uniformity in brood-rearing sage-grouse and reiterate the importance of accounting for, or at least recognizing, individual variability in population-level modeling efforts. Reclamation is increasingly emphasized as a means of mitigating impacts on species that have been affected by oil and gas development; however, the response of sagebrush species to reclamation has largely been untested. We used the Brewer’s sparrow nest survival as an indicator of population fitness responses to early-stage reclamation in sagebrush habitat. Addressing the question: does early-stage reclamation of energy disturbance provide a population benefit for the Brewer’s sparrow? We assessed oil and gas reclamation approximately five years after reclamation, but sagebrush reestablishment is a slow process; thus, the legacy of these disturbances (i.e., disturbance scars) will likely remain for decades. We compared Brewer’s sparrow nest survival across a gradient of oil and gas development from undisturbed and active development to areas that have undergone oil and gas reclamation. Nest survival was assessed at multiple scales from microhabitat to landscape. Our study was designed to also help us better understand the mechanisms that act to depress songbird nest survival in oil and gas development fields (i.e., physical footprint of disturbance or infrastructure features). The distribution of nest sites in the active CBNG development and reclamation treatments suggested local avoidance of disturbance, both active disturbance and reclamation, when establishing nesting territories. We found that reclamation benefited nest survival at a local scale which suggests that infrastructure, and associated human activity, may be more influential on Brewer’s sparrow nest predation risk than the physical footprint of disturbance alone. Our findings demonstrated scale-dependent nest survival relationships. Across microhabitat and landscape scales, sagebrush canopy cover and composition are important to Brewer’s sparrow reproductive success. Combined, these findings emphasize the importance of avoiding the removal of sagebrush habitat whenever possible and expediting sagebrush regeneration in disturbed areas to maintain suitable sagebrush habitat for breeding songbird populations

Waste-Heat-Driven Cooling Using Complex Compound Sorbents

Improved complex-compound sorption pumps are undergoing development for use as prime movers in heat-pump systems for cooling and dehumidification of habitats for humans on the Moon and for residential and commercial cooling on Earth. Among the advantages of sorption heat-pump systems are that they contain no moving parts except for check valves and they can be driven by heat from diverse sources: examples include waste heat from generation of electric power, solar heat, or heat from combustion of natural gas. The use of complex compound sorbents in cooling cycles is not new in itself: Marketing of residential refrigerators using SrCl2 was attempted in the 1920s and 30s and was abandoned because heat- and mass-transfer rates of the sorbents were too low. Addressing the issue that gave rise to the prior abandonment of complex compound sorption heat pumps, the primary accomplishment of the present development program thus far has been the characterization of many candidate sorption media, leading to large increases in achievable heat- and mass-transfer rates. In particular, two complex compounds (called "CC260-1260" and "CC260-2000") were found to be capable of functioning over the temperature range of interest for the lunar-habitat application and to offer heat- and mass-transfer rates and a temperature-lift capability adequate for that application. Regarding the temperature range: A heat pump based on either of these compounds is capable of providing a 95-K lift from a habitable temperature to a heat-rejection (radiator) temperature when driven by waste heat at an input temperature .500 K. Regarding the heat- and mass-transfer rates or, more precisely, the power densities made possible by these rates: Power densities observed in tests were 0.3 kilowatt of cooling per kilogram of sorbent and 2 kilowatts of heating per kilogram of sorbent. A prototype 1-kilowatt heat pump based on CC260-2000 has been built and demonstrated to function successfully

Microhabitat Selection for Nesting and Brood-Rearing by the Greater Sage-Grouse in Xeric Big Sagebrush

Understanding selection of breeding habitat is critical to conserving and restoring habitats for the Greater Sage-Grouse (Centrocercus urophasianus), particularly in xeric landscapes (≤25 cm annual precipitation). We monitored radio-marked female sage-grouse in south-central Wyoming in 2008 and 2009 to assess microhabitat use during nesting and brood rearing. For each model we grouped variables into three hypothesis sets on the basis of the weight of support from previous research (a priori information). We used binary logistic regression to compare habitat used by grouse to that at random locations and used an information-theoretic approach to identify the best-supported models. Selection of microhabitat for nests was more positively correlated with mountain big sagebrush (Artemisia tridentata vaseyana) than with Wyoming big sagebrush (A. t. wyomingensis) and negatively correlated with cheatgrass. Nesting hens also selected microhabitats with greater litter cover. Microhabitat for brood-rearing had more perennial grass and sagebrush cover than did random locations. Microhabitat variables most supported in the literature, such as forb cover and perennial grass cover, accounted for only 8% and 16% of the pure variation in our models for early and late brood rearing, respectively. Our findings suggest sage-grouse inhabiting xeric sagebrush habitats rely on sagebrush cover and grass structure for nesting as well as brood-rearing and that at the microhabitat scale these structural characteristics may be more important than forb availability. Therefore, in xeric sagebrush, practices designed to increase forb production by markedly reducing sagebrush cover, as a means to increase sage-grouse productivity, may not be justified

Greater Sage-Grouse (Centrocercus Urophasianus) Select Nest Sites and Brood Sites Away From Avian Predators

Greater Sage-Grouse (Centrocercus urophasianus) have declined in distribution and abundance in western North America over the past century. Depredation of nests and predation of chicks can be two of the most influential factors limiting their productivity. Prey species utilize antipredation behaviors, such as predator avoidance, to reduce the risk of predation. Birds in general balance the dual necessity of selecting cover to hide from visual and olfactory predators to enhance prospects of survival and reproductive success, which may also be achieved by selecting habitat with relatively fewer predators. We compared avian predator densities at Greater Sage-Grouse nests and brood locations with those at random locations within available sage-grouse habitat in Wyoming. This comparison allowed us to assess the species\u27 ability to avoid avian predators during nesting and early brood rearing. During 2008–2010, we conducted 10-min point-count surveys at 218 nests, 249 brood locations from 83 broods, and 496 random locations. We found that random locations had higher densities of avian predators compared with nest and brood locations. Greater Sage-Grouse nested in areas where there were lower densities of Common Ravens (Corvus corax), Black-billed Magpies (Pica hudsonia), Golden Eagles (Aquila chrysaetos), and hawks (Buteo spp.) compared with random locations. Additionally, they selected brood-rearing locations with lower densities of those same avian predators and of American Kestrels (Falco sparverius), compared with random locations. By selecting nest and brood-rearing locations with lower avian predator densities, Greater Sage-Grouse may reduce the risk of nest depredation and predation on eggs, chicks, and hens

Greater Sage-Grouse (Centrocercus Urophasianus) Select Habitat Based on Avian Predators, Landscape Composition, and Anthropogenic Features

Prey species minimize the risk of predation directly by avoiding predators and indirectly by avoiding risky habitat. Habitat loss and fragmentation have been prevalent in Greater Sage-Grouse (Centrocercus urophasianus; hereafter “sage-grouse”) habitat, which has necessitated a better understanding of mechanisms driving habitat use. Using multinomial logistic regression, we compared landscape attributes and anthropogenic features (indirect mechanisms) and densities of avian predators (direct mechanisms) among 792 sage-grouse locations (340 nests, 331 early brood, and 121 late brood) and 660 random locations in Wyoming, USA, in 2008–2011. Anthropogenic features included oil and gas structures, communication towers, power lines, roads, and rural houses; and landscape attributes included a normalized difference vegetation index (NDVI), topographic ruggedness, the proportion of big sagebrush (Artemisia spp.), and proximity and proportion variables for forested and riparian habitats. Sage-grouse locations were best described with models that included multiple habitat variables and densities of small, medium, and large avian predators. Thus, both indirect and direct mechanisms of predator avoidance were employed by sage-grouse to select habitat and presumably lower their exposure to predation and nest predation. At all reproductive stages, sage-grouse selected flatter locations with a greater proportion of big sagebrush, a higher NDVI, and lower densities of oil and gas structures. Nest locations had a lower density of major roads and were farther away from riparian habitat; early-brood locations had a lower density of power lines and were closer to rural houses; and late-brood locations were closer to riparian habitat. The magnitudes of direct and indirect avoidance by sage-grouse hens were dependent on a sage-grouse\u27s reproductive stage. Differential habitat use of female sage-grouse relative to predation risk and food availability was a means for sage-grouse hens to lower their risk of predation and nest predation, while using habitat to meet their energetic requirements and those of their chicks

The Influence of Mitigation on Sage-Grouse Habitat Selection within an Energy Development Field

Growing global energy demands ensure the continued growth of energy development. Energy development in wildlife areas can significantly impact wildlife populations. Efforts to mitigate development impacts to wildlife are on-going, but the effectiveness of such efforts is seldom monitored or assessed. Greater sage-grouse (Centrocercus urophasianus) are sensitive to energy development and likely serve as an effective umbrella species for other sagebrush-steppe obligate wildlife. We assessed the response of birds within an energy development area before and after the implementation of mitigation action. Additionally, we quantified changes in habitat distribution and abundance in pre-and post-mitigation landscapes. Sage-grouse avoidance of energy development at large spatial scales is well documented. We limited our research to directly within an energy development field in order to assess the influence of mitigation in close proximity to energy infrastructure. We used nestlocation data (n = 488) within an energy development field to develop habitat selection models using logistic regression on data from 4 years of research prior to mitigation and for 4 years following the implementation of extensive mitigation efforts (e.g., decreased activity, buried powerlines). The post-mitigation habitat selection models indicated less avoidance of wells (well density beta = 0.18 +/- 0.08) than the pre-mitigation models (well density beta = -0.09 +/- 0.11). However, birds still avoided areas of high well density and nests were not found in areas with greater than 4 wells per km(2) and the majority of nests (63%) were located in areas with <= 1 well per km(2). Several other model coefficients differed between the two time periods and indicated stronger selection for sagebrush (pre-mitigation beta = 0.30 +/- 0.09; postmitigation beta = 0.82 +/- 0.08) and less avoidance of rugged terrain (pre-mitigation beta = -0.35 +/- 0.12; post-mitigation beta = -0.05 +/- 0.09). Mitigation efforts implemented may be responsible for the measurable improvement in sage-grouse nesting habitats within the development area. However, we cannot reject alternative hypotheses concerning the influence of population density and intraspecific competition. Additionally, we were unable to assess the actual fitness consequences of mitigation or the source-sink dynamics of the habitats. We compared the pre-mitigation and post-mitigation models predicted as maps with habitats ranked from low to high relative probability of use (equal-area bins: 1 -5). We found more improvement in habitat rank between the two time periods around mitigated wells compared to non-mitigated wells. Informed mitigation within energy development fields could help improve habitats within the field. We recommend that any mitigation effort include well-informed plans to monitor the effectiveness of the implemented mitigation actions that assess both habitat use and relevant fitness parameters.Anadarko Petroleum Corporatio

Mitigation Effectiveness for Improving Nesting Success of Greater Sage-Grouse Influenced by Energy Development

Sagebrush Artemisia spp. habitats being developed for oil and gas reserves are inhabited by sagebrush obligate species--including the greater sage-grouse Centrocercus urophasianus (sage-grouse) that is currently being considered for protection under the U.S. Endangered Species Act. Numerous studies suggest increasing oil and gas development may exacerbate species extinction risks. Therefore, there is a great need for effective on-site mitigation to reduce impacts to co-occurring wildlife such as sage-grouse. Nesting success is a primary factor in avian productivity and declines in nesting success are also thought to be an important contributor to population declines in sage-grouse. From 2008 to 2011 we monitored 296 nests of radio-marked female sage-grouse in a natural gas (NG) field in the Powder River Basin, Wyoming, USA, and compared nest survival in mitigated and non-mitigated development areas and relatively unaltered areas to determine if specific mitigation practices were enhancing nest survival. Nest survival was highest in relatively unaltered habitats followed by mitigated, and then non-mitigated NG areas. Reservoirs used for holding NG discharge water had the greatest support as having a direct relationship to nest survival. Within a 5-km2 area surrounding a nest, the probability of nest failure increased by about 15% for every 1.5 km increase in reservoir water edge. Reducing reservoirs was a mitigation focus and sage-grouse nesting in mitigated areas were exposed to almost half of the amount of water edge compared to those in non-mitigated areas. Further, we found that an increase in sagebrush cover was positively related to nest survival. Consequently, mitigation efforts focused on reducing reservoir construction and reducing surface disturbance, especially when the surface disturbance results in sagebrush removal, are important to enhancing sage-grouse nesting success

Solid state generators and energy harvesters for waste heat recovery and thermal energy harvesting

This review covers solid state thermal to electrical energy converters capable of transforming low grade heat directly into electricity for waste heat recovery and thermal energy harvesting. Direct solid state heat engines, such as thermoelectric modules and thermionic converters for spatial temperature gradients, are compared with pyroelectric energy harvesters and thermomagnetic generators for transient changes in temperature. Temperature and size limitations along with the maturity of the technologies are discussed based on energy density and temperature range for the different generator technologies. Despite the low energy conversion efficiency with solid state generators, electric power density ranges from 4 nW/mm2 to 324 mW/mm2. The most promising sector to implement changes while reducing the primary energy consumption and saving resources, is the processing industry along with stationary and mobile electronics

Review on the developments of active magnetic regenerator refrigerators – Evaluated by performance

© 2020 Magnetic/magnetocaloric refrigeration is an energy-efficient and environmentally safer cooling technology with the potential to be an alternative to conventional vapor compression systems in the future. Magnetocaloric effect (MCE) is a measure of relative temperature rise/drop of certain ferromagnetic materials upon the application/removal of a magnetic field. The technology uses MCE of some materials such as Gd to produce temperature difference/span relative to the ambient via a four-stage regenerative cycle known as active magnetic regenerative (AMR) cycle. Research in this area has been thriving especially during the last two decades focussing on different aspects of technology such as materials, magnetic field sources, and system design. On the system design, studies investigating the effect of different magnetic, thermal-hydraulic, and geometric parameters on the performance have been found in the literature. The present work offers a chronological review and comparison of recent advances in AMR refrigerators. Findings and results reported in the literature are compared in terms of magnetocaloric materials, geometric parameters (such as regenerator geometry); operating parameters e.g. cycle frequency, utilization, heat transfer fluid, heat rejection temperature, and cooling load, etc. Besides, performance indicators such as no-load temperature span, cooling capacity, and/or system coefficient of performance have been considered. Parametric sensitivity and performance trends have been identified and discussed. Major barriers to achieving system peak performance and hence the marketability of the technology are also highlighted