IMPACTS OF RECREATIONAL AVIATION ON WILDLIFE: THE PHYSIOLOGICAL STRESS RESPONSE IN WHITE-TAILED DEER (Odocoileus virginianus) AND ASSOCIATED USER PERCEPTIONS

Recreational aviation on public lands may negatively impact wildlife. However, land-use decisions need to balance user need with wildlife impact. We know very little about 1) how back country airstrip use affects local wildlife, or 2) attitudes and perceptions of recreational pilots toward possible management actions. For my Master’s research, I investigated how aircraft activity influenced physiological measures of stress in white-tailed deer, while also modeling how psychometrics such as wildlife attitudes and place attachment predict the willingness of recreational pilots engage in impact-mitigating behaviors. I measured physiological stress through non-invasive sampling of stress hormones in fecal samples (fecal glucocorticoid metabolites: FGM). My results suggest that neither air traffic rates nor amount of human presence at recreation sites explained variation in FGM; however, much of the variation in deer FGM can be explained by abiotic factors such as wind velocity and precipitation. A quantitative survey of recreational pilots revealed that more positive attitudes toward wildlife were associated with greater support for impact-mitigating behaviors, while stronger place attachment to airstrips resulted in more negative attitudes toward these behaviors. Viewing recreation areas as socio-ecological systems calls for a multi-disciplinary approach, and employing biological and social science to study anthropogenic impacts on wildlife is the conceptual basis for integrative wildlife planning. By investigating organismal responses of wildlife to recreational aviation and attitudes of this user group, my aim was to provide an initial look into the impacts of recreational aviation within the framework of integrative wildlife planning

Recreational Aviation and Wildlife: the Physiological Stress Response in Deer and Associated User Perceptions

Backcountry aviation is a popular form of recreation throughout the northern Rocky Mountains; however, it is unclear whether this seasonal disturbance has adverse effects on wildlife. Using stress physiology techniques provides a mechanistic understanding of the effects of disturbance on free-living populations. The analysis of fecal glucocorticoid metabolites (FGM) is an increasingly useful tool in conservation biology as it provides a non-invasive measurement of circulating stress hormones (e.g., cortisol) deposited into the feces. We quantified aircraft activity and human presence in concert with collecting white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) fecal samples from six backcountry airstrips and six non-airstrip recreational sites (n=12) located on public land throughout western Montana and north-central Idaho. By modeling deer FGM levels at these sites, we can evaluate the impacts of backcountry aviation on wildlife stress responses within the greater context of recreation on public lands. We also surveyed recreational pilots who frequent backcountry airstrips in the study area. The main objectives of this human dimensions analysis are to 1) measure attitudes of pilots toward seeing various wildlife species at backcountry airstrips and 2) evaluate scenarios under which pilots might alter their recreational behavior in order to mitigate potential wildlife impacts. This research represents the first attempt to model the endocrine profile of wildlife populations exposed to recreational, backcountry aviation while also providing data on current stakeholder attitudes regarding this topic. In doing so, we can gain an integrated understanding of the factors surrounding recreational aviation and wildlife backcountry airstrips

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Assessing the sensitivity and repeatability of permanganate oxidizable carbon as a soil health metric: An interlab comparison across soils

Soil organic matter is central to the soil health framework. Therefore, reliable indicators of changes in soil organic matter are essential to inform land management decisions. Permanganate oxidizable carbon (POXC), an emerging soil health indicator, has shown promise for being sensitive to soil management. However, strict standardization is required for widespread implementation in research and commercial contexts. Here, we used 36 soils—three from each of the 12 USDA soil orders—to determine the effects of sieve size and soil mass of analysis on POXC results. Using replicated measurements across 12 labs in the US and the EU (n = 7951 samples), we quantified the relative importance of 1) variation between labs, 2) variation within labs, 3) effect soil mass, and 4) effect of soil sieve size on the repeatability of POXC. We found a wide range of overall variability in POXC values across labs (0.03 to 171.8%; mean = 13.4%), and much of this variability was attributable to within-lab variation (median = 6.5%) independently of soil mass or sieve size. Greater soil mass (2.5 g) decreased absolute POXC values by a mean of 177 mg kg−1 soil and decreased analytical variability by 6.5%. For soils with organic carbon (SOC) >10%, greater soil mass (2.5 g) resulted in more frequent POXC values above the limit of detection whereas the lower soil mass (0.75 g) resulted in POXC values below the limit of detection for SOC contents −1 while decreasing the analytical variability by 1.8%. In general, soils with greater SOC contents had lower analytical variability. These results point to potential standardizations of the POXC protocol that can decrease the variability of the metric. We recommend that the POXC protocol be standardized to use 2.5 g for soils <10% SOC. Sieve size was a relatively small contributor to analytical variability and therefore we recommend that this decision be tailored to the study purpose. Tradeoffs associated with these standardizations can be mitigated, ultimately providing guidance on how to standardize POXC for routine analysis.</p

Multi-messenger Observations of a Binary Neutron Star Merger

International audienceOn 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of $\sim 1.7\,{\rm{s}}$ with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) at a luminosity distance of ${40}_{-8}^{+8}$ Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 $\,{M}_{\odot }$. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at $\sim 40\,{\rm{Mpc}}$) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position $\sim 9$ and $\sim 16$ days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta