How hummingbird feeders, eDNA, and community science expanded the range of a Critically Endangered bat.
06.17.25
By Rachel Harper
“Magical” eDNA
When you lick a lollipop, as one often does, you leave a little bit of your DNA behind. A sort of exchange for the delicious sugar as it hits your tongue. Now imagine you’re a long-tongued nectar-loving bat visiting the blossom of an agave. The bat flies towards its bright, yellow target, stretches out its long pink tongue, and licks up the delicious nectar from deep inside the flower. And in doing so the bat drinks nectar, collects pollen, and also leaves behind a DNA marker that’s evidence of its presence. Until recently, scientists didn’t have the technology to detect this DNA. But thanks to eDNA (environmental DNA), we can now detect when species DNA has been left somewhere within the environment. A valuable piece of information for scientists, if only they could test every agave on every mile of the hundreds of miles stretch on their migration route…
The Secretive Bat
Climate change, habitat loss, and unsustainable collection of agaves before they bloom to produce liquor have resulted in diminishing numbers of agaves and, in turn, devastating loss of the Endangered Mexican long-nosed bat (Leptonycteris nivalis). Not only do they fly long distances every year, relying on the agave corridor for food, females do it while pregnant, and give birth and nurse once they make it north! You can imagine the amount of calories, and nectar, required to sustain such an arduous journey. In order to support these bat populations, BCI has been restoring the agave corridor, working with partners and communities to plant and preserve agaves in the most needed places. But without knowing where the bats fly and migrate through, it’s hard to know where to plant.
Photo: Mallory Davies
Strength in Numbers
Gloves, polyester swabs, vials with preservation solution, and willing volunteers. Starting in 2023, BCI recruited 34 community scientists in Arizona and New Mexico with a unique mission – swab hummingbird feeders. Yes, hummingbird feeders. It turns out that nectar-thirsty bats will opportunistically feed on backyard hummingbird feeders if given the chance. And since they’re not competing with hummingbirds in the dark, chances are great. As you can imagine, you don your gloves, swab the feeder, put the swab in the preservation solution, and send it off to the lab! Meanwhile, BCI scientists use the same method but strategically swab wild agave blossoms. And now we wait to see…
Burke, R.A., J.K. Frey, A. Ganguli, and K.E. Stoner. 2019. Species distribution modeling supports ‘‘nectar corridor’’ hypothesis for migratory nectarivorous bats and conservation of tropical dry forest. Diversity and Distributions 25:1399-1415
The Findings
This unique project led to the first confirmed detection of the endangered Mexican long-nosed bat in Arizona, expanding their known range! And now that we know this method works, we can continue to expand upon the work and fill in the knowledge gaps of the migratory route, allowing for BCI’s Agave Restoration Team to strategically plant agaves where the bats go. The Agave Restoration Team’s goal is to plant over 500,000 agaves and restore or protect 230,000 acres of land in critical areas for these bats, as well as establishing 20 greenhouses by 2035. Additionally, the data can now be used to protect critical foraging areas and hint at possible future expansion sites to plant agaves as the climate warms and the bats may need to go further north. And thanks to this proven method of community scientists contributing to eDNA sampling, who knows what other scientific questions could be answered in the future using similar procedures.
The Agave Restoration Team
Kristen Lear, Ph.D. – Agave Restoration Program Director
Dr. Lear is the Agave Restoration Program Director in charge of BCI’s bi-national Agave Restoration Initiative. She got her start in bat conservation in 6th grade when she built and installed bat houses for her Girl Scout Silver Award project. Since then, she has worked on bat research, conservation, and education projects around the world.
She earned a BA in Zoology from Ohio Wesleyan University in 2011, where she assisted with a project studying the pest control services of bats in pecan orchards and led a bat house study for her Honors research. Following graduation, she earned a Fulbright Scholarship to study the critically endangered Southern bent-wing bat (Miniopterus schreibersii bassanii) in South Australia. In 2020, Kristen earned her Ph.D. in Integrative Conservation from the University of Georgia. Her Ph.D. work combined natural and social science approaches to aid in the conservation of the endangered Mexican long-nosed bat (Leptonycteris nivalis) in northeast Mexico.
Kristen is a National Geographic Explorer, AAAS IF/THEN Ambassador working to encourage girls and young women in STEM fields, and a Lifetime Member of Girl Scouts. She is also passionate about public outreach and education, giving numerous bat talks at schools and organizations around the world, leading public bat walks and bat house building workshops, and making numerous media appearances, including on CBS’ “Mission Unstoppable” TV show. More information about Kristen’s work can be found here.
Rachel Burke – Agave Restoration Coordinator
Rachel joined BCI as the Agave Restoration Coordinator in 2023. As part of the Endangered Species Intervention team, Rachel works with the Agave Restoration Program on applied conservation for nectar feeding bats in the southwestern United States. She collaborates with native plant growers, land managers, land owners, and other stakeholders to promote a resilient landscape for nectar feeding bats.
For the past decade, Rachel has been working in wildlife management, ecological monitoring, and habitat restoration across the Chihuahuan and Sonoran Deserts. In 2018, she completed a dual masters program in Fish, Wildlife, and Conservation Ecology, and Applied Geography from New Mexico State University. Her thesis work focused on using geospatial modeling to inform applied management and habitat restoration for nectar-feeding bats. Her graduate work brought her to some of the most beautiful parts of the desert sky islands, which quickly became her favorite ecosystem to work in.
Rachel has worked in a variety of positions in the public and private sector, ranging from leading an ecological monitoring crew, analyzing national botany datasets, and working as a federal wildlife biologist for both the Bureau of Land Management and U.S. Forest Service. Outside of work, Rachel can typically be found in her basement pottery studio, working in her garden with her dogs, or training for an ultra on the trails outside of Las Cruces, New Mexico.
Brianna Mann joined BCI as a part-time technician for the Subterranean and Restoration teams in March 2022 before transitioning into a full-time role as a Restoration Specialist in November 2022. Prior to this, Brianna worked in natural history collections, as a springs biologist in the Southwest, and monitored wildlife (including acoustic monitoring of bats) throughout the western United States.
In her current role as Restoration Specialist, Brianna hopes to put her life-long passion for wildlife ecology to good use by protecting habitats for bats and other wildlife, restoring and stabilizing vital natural resources, and monitoring the impacts of habitat changes on wildlife populations. She believes that connection and collaboration are the gateways to successful conservation of the world’s biodiversity.
Brianna lives in Flagstaff Arizona, and in her spare time enjoys all things outdoors, reading, writing, dancing, and a good local brew.
About the Author
Rachel Harper – Digital Marketing Manager
Rachel joined Bat Conservation International in 2021, fostering BCI’s digital presence and community to support ending bat extinctions worldwide.
Rachel has a Bachelor’s in Marketing and over ten years experience in the digital conservation field, ranging from directing the Communications department at a local nature center to crafting social media strategies for San Diego Zoo Wildlife Alliance, and volunteering as Marketing Director for a nonprofit in Costa Rica.
Rachel grew up in Reno, Nevada and spent much of her childhood hiking and camping in Lake Tahoe, which inspired her passion for conserving wildlife and learning about nature. She now enjoys hiking, snorkeling, and experiencing wildlife in San Diego, California.
