UA-Based Network Looks Out for Lesser Long-Nosed Bat
The bat, one of three nectar-feeding bats in the U.S., has been delisted as an endangered species and is flourishing. Efforts such as Flowers for Bats will ensure that it continues to thrive.

By Stacy Pigott, University Communications
April 18, 2018


The lesser long-nosed bat is an important pollinator of cactuses in the Southwest.
The lesser long-nosed bat is an important pollinator of cactuses in the Southwest. (Courtesy of Bruce D. Taubert/Bat Conservation International)

In 1988, the lesser long-nosed bat was placed on the U.S. Federal List of Endangered and Threatened Wildlife when fewer than 1,000 remained in just 14 roosts. On Wednesday, the U.S. Fish and Wildlife Service removed the bat's classification as an endangered or threatened species, citing an estimated and thriving population of 200,000 in 75 roost sites.

One of three nectar-feeding bats in the U.S., the lesser long-nosed bat travels north from Mexico annually on a journey that can cover almost 1,000 miles. It settles in maternity roost sites in southern Arizona and southwestern New Mexico, feeding on the nectar and pollen of column cactuses such as saguaros and three species of agave — Palmer's century plant, Parry's agave and desert agave.

A migratory pollinator and seed disperser, the lesser long-nosed bat (Leptonycteris curasoae yerbabuenae) occupies an important place in the regional ecosystem. Mexican tequila producers who rely on agaves assisted in recovery efforts that also included federal and state agencies, non-governmental organizations, biologists and citizen scientists. The result is the lesser long-nosed bat being the first bat ever removed from the U.S. endangered species list. It was delisted by Mexico in 2015.

"Now that the bat has been removed from the endangered species list, the Fish and Wildlife Service will continue to monitor the bats and their food sources to ensure that the population stays healthy," said Erin Posthumus, outreach coordinator for the USA National Phenology Network, or USA-NPN, which is hosted within the School of Natural Resources and the Environment in the University of Arizona's College of Agriculture and Life Science.

Funded by the U.S. Geological Survey and the U.S. Fish and Wildlife Service, USA-NPN collects, stores and shares data on cyclical and seasonal phenomena of local plant and animal species. Through Nature's Notebook, professional and citizen scientists record long-term observations of plant and animal life stages.

Flowers for Bats, a collaboration between the U.S. Fish and Wildlife Service and USA-NPN, seeks to understand how the availability of bat nectar sources is shifting over time. Flowers for Bats specifically focuses on documenting the flowering of saguaro and agave that provide vital nectar for the lesser long-nosed bat.

"The Flowers for Bats effort is an important component of the post-delisting monitoring plan for the bat," said Posthumus, who serves as USA-NPN's liaison to the Fish and Wildlife Service at the UA.

Flowers for Bats and other Nature’s Notebook campaigns rely on the efforts of local community members and partners to collect data. USA-NPN research assistant and CALS undergraduate student Sierra Frydenlund is diving into long-term datasets from the Arizona-Sonora Desert Museum and other locations that have been documenting flowering phenology of these species for decades.

"Overall, this project has been interesting to work on, especially analyzing the phenology datasets," Frydenlund said. "I have learned more about the various measures of flowering and applying that toward the analysis of the variables of climate. I'm excited to see the results of this research and applying those results toward management of the lesser long-nosed bat."

Frydenlund hopes to combine that information with data contributed through Nature’s Notebook to better understand how flowering of nectar species is changing over time. The U.S. Fish and Wildlife Service will then use those findings to conserve and promote habitat for the lesser long-nosed bat.

"Citizen scientists are critical to the Flowers for Bats effort. I think this project really captures the culture of the local area of Tucson," Frydenlund said. "Citizens are in tune with the surrounding environment of the Sonoran Desert, so they are interested in the conservation of saguaros and agaves. By tracking the flowering of saguaros and agaves, they can help us better understand when and where nectar is available for bats. This project harnesses that desire for the collection of data that is usable for science."

The Arizona Game and Fish Department has been using the power of citizen science to monitor bat behavior, as both lesser long-nosed bats and Mexican long-tongued bats have been observed using hummingbird feeders in urban areas. During the summer, residents of Tucson and surrounding areas can help by checking hummingbird feeders for signs of bat use and reporting the findings online. Some of the data collected over the past 10 years contributed to recovery efforts for the lesser long-nosed bat. 

Extra info

Ways to get involved:

• Sign up to volunteer with Flowers for Bats online:

• Attend an in-person Flowers for Bats training session at the Tucson Botanical Gardens on Thursday, April 19, from 3 to 5 p.m.:

• Join phenology enthusiasts on a coffee walk the fourth Monday of each month at 8:30 a.m. in the Joseph Wood Krutch Garden, located outside the UA Student Union Memorial Center.

• Register to watch your hummingbird feeder for visits by nectar-feeding bats at


Resources for the media

Erin Posthumus

UA School of Natural Resources and the Environment