White-nose Syndrome and Grand Canyon Bats
Originally from Europe, White-Nose Syndrome is an incredibly dangerous disease that has spread across North American at an alarming rate, killing millions of bats. Originally located in a cave in New York in 2006, this disease has now been identified in 28 US States and 5 Canadian Provinces.In March 2016, an infected bat was found in Washington State- the first evidence of the disease west of the Rocky Mountains.In the northeast United States, where WNS was first detected, bat populations have fallen by 80%- in many hibernacula (caves where bats hibernate) mortality rates are 100%. Caused by the fungus Pseudogymnoascus destructans, this disease is characterized by a white fungus that infects the muzzles, ears, and wings of hibernating bats.Irritation from the growth of the fungus wakes up bats during hibernation—forcing them to use the precious stores of fat and water they need to survive the winter. The main causes of death from WNS are starvation and trauma from the destruction of the wing membrane. In order to save bat populations from the massive threat of this disease, critical research must be done to understand which species are most vulnerable, where they live, and how we can protect them.
Grand Canyon has the highest bat diversity of any part of the National Park Service, but little is known about the distribution, population sizes, and activity patterns of the 22 species that live within the Park. The goal of current research is to create a baseline index of bat diversity in Grand Canyon National Park. By understanding the current populations, park biologists can better assess changes in population size, range, and activity patterns. This way, park biologists will know when WNS arrives in Grand Canyon National Park, and will better understand its impacts.
Working with the AZ Game and Fish Department, park biologists have established a series of monitoring sites. Each site has an acoustic monitoring station that monitors bat activity throughout the year. Comprised of a microphone, receiver, solar panel, and battery, these acoustic monitors record bat calls which are later identified. Designed to be left in the field for years at a time, acoustic monitoring stations can collect enormous amounts of data, documenting which species are in an area and bat activity patterns throughout the year. These monitoring sites are supplemented with three bat captures a year, where biologists capture bats at each site in the spring, summer, and fall. Bats are captured using mist nets—nets made of fine quality mesh that is almost invisible to bats and is too fine to harm them. When a bat flies into the net, it becomes tangled, and biologists untangle it and then identify and measure the bat before it is released. By physically capturing bats, biologists can examine them for the tell-tale white mask of fungus, fungus on the wings, and other signs of WNS. Frequent capture events will allow biologists to more accurately determine when WNS arrives in Grand Canyon National Park.
These 11 monitoring sites are placed at different elevations in the Canyon: 2 on the North Rim, 2 on the South Rim, 4 midway down the canyon, and 3 along the river. By placing these sites along an elevational gradient, biologists can study bat activity at different elevations in the canyon throughout the year. One theory, which will be tested with this research, is that during the winter bats abandon the Rims (where weather regularly drops below freezing) and instead of hibernating they concentrate their activity near the Colorado River (which is 5000 feet lower in elevation and stays relatively warm throughout the winter). By avoiding hibernation, species that are normally susceptible to WNS may survive the worst impacts of this disease.
By studying the distribution, population size, and behavior of bats in the Grand Canyon, biologists hope to learn how these incredible animals will be affected by WNS, and how bats can be protected from this dangerous disease.
Last updated: May 17, 2021