Last updated: July 14, 2017
Article
Bat Monitoring at Glen Canyon National Recreation Area
At a time when bat populations are at a greater risk of extinction, the National Park Service has a strategic role to play in continent-wide bat conservation. Glen Canyon National Recreation Area is participating in the North American Bat Monitoring Program, conducting acoustic surveys and netting bats throughout the park. In addition, park scientists are involving youth in citizen science bat monitoring projects and bringing bat science to the public by hosting annual bat festivals.
© Josh More, some rights reserved (CC BY-NC-ND 2.0)
Importance of bats
Bats comprise the second most diverse order of mammals—the Order Chiroptera. They make up 20% of all known living mammals, with approximately 1,240 plus species (Harvey et al. 2011), and are found on all continents except Antarctica (Bogan et al. 1996, Wund and Myers 2005). Wherever they occur, bats perform vital ecological roles which often affect human health and agriculture. For example, bats that eat insects help to control insect pests that can carry disease to humans and crops. One little brown bat (Myotis lucifugus) can catch up to 600 mosquitos an hour (Walldorf and Mehlhorn 2014). Fruit-eating bats disperse seeds and help to maintain the diversity of fruit trees. Bats that eat pollen and nectar perform the very important role of pollinating plants (Wund and Myers 2009).
Threats and challenges to the survival of bats in North America
About 47 species (Harvey et al. 2011) of bats occur in North America (Canada and the United States). More than a quarter of these are listed under the US Endangered Species Act—11 species are listed as endangered and 2 are listed as threatened (USFWS 2017). Wind turbines, habitat loss, climate change, and disease are among the factors posing serious threats to bat survival. Furthermore, bats are long-lived mammals with very low reproductive rates—females of most bat species give birth to only one pup a year (Arnett et al. 2016). If the number of bats in a community is severely reduced, this low reproductive rate hampers the recovery of the population.Wind turbines and bats
Wind power is one of the fastest growing sources of renewable energy around the world. However, wind turbines and the activities involved in wind energy development can negatively affect bat habitat and kill bats. It is estimated that hundreds of thousands of bats are killed in the US each year due to wind energy (Bat Conservation International 2017). Bat deaths can be caused by direct impact with wind turbines, but are also thought to be a result of barotrauma—lung damage due to the sudden air pressure changes that occur near moving turbines (Grodsky et al. 2011, Baerwald, et al. 2008).
Habitat loss
Habitat loss is a major threat to wildlife species all over the world. When land is developed, or converted to agricultural uses, or forests are cut for timber, areas that bats use for roosting and foraging are lost. In addition, potential food sources may become harder for bats to find as the landscape becomes fragmented (Bat Conservation International 2017, Treitler et al. 2016).
Climate change
The effects of increasing temperatures on bats due to climate change are not completely understood. Some studies indicate that temperature changes may alter the distribution of hibernating bats. Other studies provide evidence that increased evapotranspiration and a decrease in surface water brought on by rising temperatures can reduce reproduction rates in some bat species (Rodhouse et al. 2016).
Disease
A major factor in some bat population declines is disease (Alves et al. 2014). One of the most devastating wildlife diseases has been White-Nose Syndrome (WNS), which was discovered in the late winter of 2007 (Frick et al. 2016). During their annual winter surveys, biologists of the New York Department of Environmental Conservation discovered dead bats covering cave floors and bats flying about in winter when they should have been hibernating.
© John MacGregor, some rights reserved (CC BY-SA 2.0)
The disease is caused by a fungus—Pseudogymnoascus destructans—believed to have been brought to North America from Europe by humans (Frick et al. 2016). Research has shown that the effects of the fungus causes bats to come out of hibernation in winter, depleting the fat they need to sustain them until food becomes available in the spring. The disease has spread rapidly. As of June 2017, it has affected 31 states and 5 Canadian Provinces, killing millions of bats (https://www.whitenosesyndrome.org/about/where-is-it-now).
White-Nose Syndrome attacks hibernating bats. In North America, there are 25 species of hibernating bats and all are considered at risk for the disease (Alves et al. 2014). To date, in North America, 9 species have been confirmed with diagnostic symptoms of WNS, two of which were already listed as federally-endangered in the U.S. The fungus P. destructans has been detected on 6 additional species, but with no diagnostic signs of WNS (https://www.whitenosesyndrome.org/about/bats-affected-wns). The Northern long-eared bat (Myotis septentrionalis) was listed as threatened in 2015, and the little brown bat, once the most common of bat species, is now being considered for listing (Alves et al. 2014).
North American Bat Monitoring Program
In the face of these continuing and emerging threats to bats in North America, the North American Bat Monitoring Program (NABat) was launched. The purpose of this multiagency, international effort is to provide a continent-wide program to monitor bats at local to landscape scales. The data from this project will guide effective bat conservation that will hopefully lead to the long-term viability of bat populations (Loeb et al. 2015). The program uses four strategies to collect the data needed to assess changes in bat distributions and abundances:
- winter hibernaculum counts
- maternity colony counts
- mobile acoustic surveys along road transects
- acoustic surveys at specific points
NABat utilizes a sampling frame that consists of 10 X 10 km grid cells and covers Canada, the United States, and Mexico. The sampling frame design is flexible and facilitates monitoring across multiple partner jurisdictions. Acoustic monitoring is conducted within the 100 km2 using stationary bat detectors. Some bats are not detectable acoustically, so colony counts of bats at hibernacula and summer roosts must also be conducted.
For more information about the North American Bat Monitoring Program, please see the protocol at https://www.srs.fs.usda.gov/pubs/gtr/gtr_srs208.pdf.
Bat monitoring at Glen Canyon National Recreation Area
The National Park Service (NPS) has an integral role to play in bat conservation. All of the 15 species known to be susceptible to WNS, or to be carriers of the fungus causing the disease, are found within the U.S. National Park Service system. Forty-three park units were confirmed or suspected as positive for WNS as of October 2015; it is estimated that the disease could potentially spread to 127 parks by 2026. In addition, Rodhouse et al. (2016) found that NPS units overlap the ranges of most of the bats in North America to a great extent, further supporting the strategic role the NPS will play in continent-wide bat conservation in the future.
Glen Canyon National Recreation Area (NRA) has been conducting bat research since the 1950s. Prior to 2015, surveys were conducted using mist nets. In 2015, park researchers, with assistance from Grand Canyon National Park, University of Arizona, and Grand Staircase Escalante National Monument staff, resampled sites from historical efforts and several new sites. Acoustic monitoring was also conducted. In 2016 the park began participating in the NABat monitoring program, adopting ten 100 km2 grid cells. Three bats that had never been recorded in the park before are believed to have been found through the acoustic monitoring (but not yet confirmed): little brown myotis , greater mastiff bat (Eumops perotis), and the long-eared myotis (Myotis evotis). Recently, the park compiled a list of species from historical records as well as species detected in the monitoring conducted in 2015 and 2016. The resulting list contained 18 bat species (Table 1, Levorse et al. 2016).
| Common name | Scientific name | Bat species affected by WNS |
|---|---|---|
| Family: Vespertilionidae | ||
| Pallid bat | Antrozous pallidus | |
| Townsend’s big-eared bat | Corynorhinus townsendii | X* |
| Big brown bat | Eptesicus fuscus | X |
| Spotted bat | Euderma maculatum | |
| Allen’s big-eared bat | Idionycteris phyllotis | |
| Silver-haired bat | Lasionycteris noctivagans | X* |
| Hoary bat | Lasiurus cinereus | |
| California myotis | Myotis californicus | |
| Western small-footed myotis | Myotis ciliolabrum | |
| Western long-eared myotis | Myotis evotis | |
| Little brown bat | Myotis lucifugus | X |
| Fringed myotis | Myotis thysanodes | |
| Long-legged myotis | Myotis volans | |
| Yuma myotis | Myotis yumanensis | X |
| Canyon bat | Parastrellus hesperus | |
| Family: Molossidae | ||
| Greater mastiff bat | Eumops perotis | |
| Big free-tailed bat | Nyctinomops macrotis | |
| Brazilian free-tailed bat | Tadarida brasiliensis | |
| *Bat species on which Pseudoymnoascus destructans has been detected, but no diagnostic sign of WNS has been documented (https://www.whitenosesyndrome.org/about/bats-affected-wns). | ||
NPS
Cultivating future scientists
What’s a good way to inspire teens to become scientists and collect some valuable data at the same time? Enlist a group to raft down the San Juan and Colorado Rivers and teach them to collect bat data along the way! In 2016, Glen Canyon NRA scientists partnered with Grand Canyon Youth, Mosaics in Science, the Student Conservation Association, OARS, the National Park Foundation, and the Glen Canyon Natural History Association to conduct a citizen science project focused on determining what bat species were using the riparian habitat along the Colorado and San Juan Rivers, and where those species were occurring. The project will be continued in 2017.
Glen Canyon NRA Bat Festival
How do you get the public to support bat conservation? Invite them to a party and teach them all about bats, of course! Glen Canyon NRA held the first of many Bat Festivals to come in 2016. Guests learned about bats, the threats they face, and how to help bats by providing them with healthy habitat. There were prizes and activities, including a bat listening walk. The 2017 Bat Festival will take place on July 22nd at the Wahweap Campground Amphitheater. For more information contact Lonnie Pilkington at e-mail us.
Adopt a bat!
Want to help with bat conservation? Visit the Glen Canyon Natural History Association’s website (http://www.glencanyonnha.org/adoptabat/) and find out how to adopt a bat. You’ll get a plush bat, certificate of adoption, and the pride of helping these very important mammals to survive into the future.
References
Alves DMCC, Terribile LC, Brito D (2014) The Potential Impact of White-Nose Syndrome on the Conservation Status of North American Bats. PLoS ONE 9(9): e107395.
Arnett, Edward B. , Erin F. Baerwald, Fiona Mathews, Luisa Rodrigues, Armando Rodríguez-Durán, Jens Rydell, Rafael Villegas-Patraca, Christian C. Voigt. 2016. Impacts of Wind Energy Development on Bats: A Global Perspective, In Christian C. Voigt and Tigga Kingston, editors, Bats in the Anthropocene: Conservation of Bats in a Changing World. Springer International Publishing, Cham, Switzerland. DOI 10.1007/978-3-319-25220-9. Available at https://link.springer.com/book/10.1007%2F978-3-319-25220-9.
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Frick, Winifred F., Sébastien J. Puechmaille and Craig K.R. Willis. 2016. White-Nose Syndrome in Bats. In C.C. Voigt and T. Kingston (eds.), Bats in the Anthropocene: Conservation of Bats in a Changing World, DOI 10.1007/978-3-319-25220-9_9.
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Harvey, M. J., Altenbach, J. S., and Best, T. L. 2011. Bats of the United States and Canada. The Johns Hopkins University Press. Baltimore, Maryland.
Levorse, Alexis, Lonnie Pilkington, and John Spence. 2016. Annotated checklist of the bats (Chiroptera) of Glen Canyon National Recreation Area, Utah and Arizona. Unpublished report. Science & Resource Management Division, National Park Service, Glen Canyon National Recreation Area, Page, Arizona.
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Prepared by Jean Palumbo, Southern Colorado Plateau Network Inventory and Monitoring Program, 2017.