Grand Canyon National Park is a hotspot for bat diversity. Twenty-two bat species have been documented in the Park, more than any other national park unit.
The presence, abundance, and foraging activity of bats is tightly linked with the availability of water, especially in arid climates. In addition to requiring drinking water, bats forage along river corridors to prey on emergent aquatic insects. Riparian vegetation provides bats with night roosts, protection from predators, and gives them close access to surface drinking water.
The Colorado River ecosystem is important for bats because it is a source of invertebrate insect prey, and riparian vegetation and canyon walls provide a corridor of suitable habitat and influence the structure of bat migration and movement patterns.
SBSC Grand Canyon Monitoring and Research Center (GCMRC) researchers are working to understand how management of the Colorado River and Glen Canyon Dam operations affect this diverse assemblage of bats through community science projects that track aquatic insects in the Colorado River ecosystem ("Community Science in Grand Canyon") as well as through monitoring the effects of experimental weekend steady flows called "Bug Flows" (Macroinvertebrate Production Flows) designed to increase aquatic insect abundance in the river.
Read a recent study that investigated aquatic insect abundance and bat foraging activity:
Metcalfe, A.N., Fritzinger, C.A., Weller, T.J., Dodrill, M.J., Muehlbauer, J.D., Yackulic, C.B., Holton, P.B., Szydlo, C.M., Durning, L.E., Sankey, J.B., and Kennedy, T.A., 2023, Insectivorous bat foraging tracks the availability of aquatic flies (Diptera): The Journal of Wildlife Management, e22414, https://doi.org/10.1002/jwmg.22414.
Safety Note: Bats and Rabies
Bats are known to carry rabies, which is a zoonotic disease that can be transmitted to humans and is fatal if untreated. Bats can spread rabies to humans through their saliva, via bites or scratches. It is important to never touch or handle bats, especially if they appear sick or are exhibiting unusual behavior such as being active during the day. Anyone who has had direct contact with a bat should seek medical consult, as rabies can only be confirmed through lab testing.
Community Science in Grand Canyon
Bug Flows: Improving Food Web Health on the Colorado River
Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River
Bat activity and insect abundance data along the Colorado River in Grand Canyon, AZ
Insectivorous bat foraging tracks the availability of aquatic flies (Diptera)
Applied citizen science in freshwater research
- Overview
Grand Canyon National Park is a hotspot for bat diversity. Twenty-two bat species have been documented in the Park, more than any other national park unit.
Water flowing into a pool in a desert canyon tributary near the Colorado River and Grand Canyon. Bats fly above the surface of the pool, drinking and catching insects. Video by Anya Metcalfe, USGS, SBSC. The presence, abundance, and foraging activity of bats is tightly linked with the availability of water, especially in arid climates. In addition to requiring drinking water, bats forage along river corridors to prey on emergent aquatic insects. Riparian vegetation provides bats with night roosts, protection from predators, and gives them close access to surface drinking water.
The Colorado River ecosystem is important for bats because it is a source of invertebrate insect prey, and riparian vegetation and canyon walls provide a corridor of suitable habitat and influence the structure of bat migration and movement patterns.
SBSC Grand Canyon Monitoring and Research Center (GCMRC) researchers are working to understand how management of the Colorado River and Glen Canyon Dam operations affect this diverse assemblage of bats through community science projects that track aquatic insects in the Colorado River ecosystem ("Community Science in Grand Canyon") as well as through monitoring the effects of experimental weekend steady flows called "Bug Flows" (Macroinvertebrate Production Flows) designed to increase aquatic insect abundance in the river.
Read a recent study that investigated aquatic insect abundance and bat foraging activity:
Metcalfe, A.N., Fritzinger, C.A., Weller, T.J., Dodrill, M.J., Muehlbauer, J.D., Yackulic, C.B., Holton, P.B., Szydlo, C.M., Durning, L.E., Sankey, J.B., and Kennedy, T.A., 2023, Insectivorous bat foraging tracks the availability of aquatic flies (Diptera): The Journal of Wildlife Management, e22414, https://doi.org/10.1002/jwmg.22414.
Safety Note: Bats and Rabies
Bats are known to carry rabies, which is a zoonotic disease that can be transmitted to humans and is fatal if untreated. Bats can spread rabies to humans through their saliva, via bites or scratches. It is important to never touch or handle bats, especially if they appear sick or are exhibiting unusual behavior such as being active during the day. Anyone who has had direct contact with a bat should seek medical consult, as rabies can only be confirmed through lab testing.
A light trap set up at dusk along the river's edge to collect and inventory aquatic insects emerging from the river. Big Brown Bat echolocation call. Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area.
- Science
Community Science in Grand Canyon
Aquatic insects are important components of riverine foodwebs as they are prey for fish, birds, bats, lizards, and spiders. The closure of Glen Canyon Dam in 1963 fundamentally altered the hydrology, water temperature, and turbidity of the Colorado River through Grand Canyon. These changes, along with competition with invasive species and limited food availability have led to the decline and...Bug Flows: Improving Food Web Health on the Colorado River
Native and desired nonnative fish downstream of Glen Canyon Dam are food limited—meaning that if more or larger invertebrate food items were available, there would be more and larger fish. Aquatic insects have complex life cycles that include egg, larvae, and pupal stages that are aquatic while adults have wings and are typically terrestrial. Aquatic insects are a fundamental component of river...Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River
Algae, phytoplankton, and rooted macrophytes represent the base of many aquatic food webs and are known as primary producers. Through photosynthesis, these organisms convert sunlight energy into chemical energy (i.e., carbon) that in turn fuels the growth of animals such as macroinvertebrates and fish. This project uses high frequency measurements of dissolved oxygen, which is a by-product of... - Data
Bat activity and insect abundance data along the Colorado River in Grand Canyon, AZ
These data were compiled to improve our understanding of bat foraging along the Colorado River in Grand Canyon. Objectives of our study were to determine whether bat activity was influenced primarily by variation in prey availability relative to other environmental or geomorphic factors. These data represent 1,428 paired samples of bat activity and insect abundance calculated as catch rates collec - Publications
Insectivorous bat foraging tracks the availability of aquatic flies (Diptera)
Rivers and their adjacent riparian zones are model ecosystems for observing cross-ecosystem energy transfers. Aquatic insects emerging from streams, for example, are resource subsidies that support riparian consumers such as birds, spiders, lizards, and bats. We collaborated with recreational river runners in Grand Canyon, Arizona, USA, to record acoustic bat activity and sample riparian insects uAuthorsAnya Metcalfe, Carol Fritzinger, Theodore J. Weller, Michael Dodrill, Jeffrey Muehlbauer, Charles Yackulic, Brandon P. Holton, Cheyenne Maxime Szydlo, Laura E. Durning, Joel B. Sankey, Theodore KennedyApplied citizen science in freshwater research
Worldwide, scientists are increasingly collaborating with the general public. Citizen science methods are readily applicable to freshwater research, monitoring, and education. In addition to providing cost-effective data on spatial and temporal scales that are otherwise unattainable, citizen science provides unique opportunities for engagement with local communities and stakeholders in resource maAuthorsAnya N. Metcalfe, Theodore A. Kennedy, Gabriella A. Mendez, Jeffrey D. Muehlbauer - News