WNS and Bat Projects: Monitoring, Modeling, Education, and Resource Protection
PI: Brandon Holton
1. Acoustic Surveys: continue long-term acoustic surveys at 11 sites.
Grand Canyon (GRCA) used the allocated funds to support personnel costs, purchase additional acoustic detectors, data storage, and associated equipment for deployment of seven additional remote acoustic stations in GRCA. Additionally this funding supported GRCA’s lead biologist to attend the Combined Field Survey Techniques for Bats Workshop in May 2016 (Bat Survey Solutions, LLC). GRCA has expanded this study to include an additional seven inner-canyon sites that incorporate both the elevational gradients and diverse biotic communities of GRCA. Climate loggers have been installed at each of the 11 sites. Acoustic stations will be deployed for a minimum of two years. These acoustic surveys have captured the diversity of bats across multiple elevational gradients, from the canyon rims to the canyon bottom, and helped us gain a better understanding of the distribution of bat species across seasons, habitat types, and topography. Acoustic information has and will continue to provide critical information about how and when bats are distributed in GRCA, and when correlated with Objectives 2-4, provide calculated risks to bat species from WNS.
2. Capture Surveys: continue seasonal bat capture surveys at the 11 long-term acoustic monitoring stations.
GRCA used the allocated funds to support personnel costs for capture surveys, capture equipment and logistical support backcountry/cave areas to be accessed for capture surveys. These surveys have allowed us to positively document bat assemblages at different spatial and temporal scales across the canyon, assess health conditions of bat individuals, and confirm how well our acoustic detectors and associated bat classifier software are performing. Since October 2015, we have mist netted for bats 22 times at 11 different locations from the canyon rims to the canyon bottom. We have captured a total of 240 bats, including 14 different species of GRCA’s known 22 different species. Thus far, we have only detected minor health associated issues with bats in GRCA, such as parasites (ticks and mites) and small wing tears. Wing scores on almost all bats have been good, and no suspect Pd infection. In September 2016, we will be repeating a capture survey conducted in 1996 to assess any trends or differences in bat assemblage along the Colorado River through GRCA across a 20 year period. Routine bat captures across all seasons will contribute to a comprehensive health assessment of bat species at GRCA and provide critical information for a tactical response in the event that Pd or WNS-infected bats are discovered in GRCA.
3. Roost Surveys: locate hibernacula/winter roost sites and monitor winter bat activity and roost climatic conditions.
GRCA used the allocated funds to support personnel costs for cave/roost access and the purchase of four roost loggers and climate loggers to be deployed at caves meeting the criteria of temperatures both conducive to hibernating bats and the growth of Pd (see Objective 4.). Bat roost surveys have provided one of the first attempts to locate hibernating bats in GRCA and qualify roost climatic conditions. Due to concerns about winter safety conditions and data quality, we redesigned this objective to include a) hibernacula surveys during peak winter months and b) long term deployment of roost and climate loggers at hibernaculum rather than acoustic detectors. This requires considerable reduction in the frequency of visits to caves, reduces safety concerns and travel costs, while still meeting original objectives of monitoring roost winter activity and climatic conditions as a precursor to Pd arrival and WNS conditions. We have deployed seven climate loggers in six different caves. Loggers will remain in place until temperature variability and winter cave temperatures can be verified. A more informed and focused effort to identify hibernaculum and roost conditions will continue this winter, based on model outputs from Objective 4.
4. Roost Modeling: develop a park-wide distribution model of caves susceptible to WNS invasion
GRCA used the allocated funds to support efforts to continue modeling and verifying caves in GRCA with the potential to harbor both hibernating bats and Pd. 69 caves have been identified within both the growth temperature range for Pd and within common bat hibernation temperature range of 8-12° C, of which three caves were within the 8.0-10.0° C range. We have deployed seven climate loggers in six different caves. Loggers will remain in place until temperature variability and winter cave temperatures can be verified. We will continue to verify temperature raster models by visiting caves predicted to be conducive to hibernating bats and WNS invasion.
5. Education & Outreach: continue to provide an engaging learning opportunity for park visitors about bats, WNS, & cave and bat protection measures
In conjunction with seasonal capture events, we have conducted four outreach events to educate park visitors about bat ecology, their importance to the GRCA ecosystem, population threats from WNS, and how best to prevent the spread of WNS to other areas. We have engaged approximately 150 visitors during these events, and approximately 100 more in route to front- and backcountry capture sites. In FY2017, we plan to engage specifically the river community about WNS threats and preventative measure to reduce the risk of spreading Pd. We have employed new National White-Nose Syndrome Decontamination Protocol (Version 04.12.2016) at all front country and back country bat capture sites, including demonstrations to park visitors and Interpretative staff. We have employed the Recommendations for Managing Access to Subterranean Bat Roosts to Reduce the Impacts of WNS by working with LE to restrict human access to Last Chance mine, a known Corynorhinus townsendii roost.