Learning the secret life of flying squirrels

The San Bernardino flying squirrel is one of 25 subspecies of northern flying squirrels (shown here) and is the most southern subspecies in the western U.S. Credit: Joshua Mayer/Flickr Creative Commons 2.0

By Jane Hendron
February 23, 2017

Flying squirrels have inhabited southern California’s San Bernardino Mountains for thousands of years, but most people have never seen one.

Now, a group of 50 citizen scientists, supported by a number of federal, state and local organizations, are trying to change that.

Most residents of San Bernardino mountain towns aren’t “even aware flying squirrels are up here,” says Nole Lilley, one of the citizen scientists studying the squirrels.

Peggy and Tom Howe, also study participants, were introduced to the species by chance – “when one got stuck in a bedroom after coming in an open window.”

A flying squirrel finds a bird feeder on Nole Lilley's deck overlooking San Bernardino and Riverside, Calif., in a photo from 2016.  Credit: Nole Lilley/USFWS

The San Bernardino flying squirrel is one of 25 subspecies of northern flying squirrels and is the most southern subspecies in the western U.S. Active mostly at night, they spend most of their time high up in pines, cedars and black oaks, venturing down only to forage.

VIDEO: Service biologist Clark Winchell explains how to
capture the San Bernardino flying squirrel with a
trail camera. Credit: C. Medina-Ontiveros/USFWS

While researchers have learned much about the squirrels, many unanswered questions remain. How common are the squirrels within their range? Do the squirrels exhibit seasonal differences in behavior? To answer these and other questions, they needed to study them within the San Bernardino National Forest, but also on private property in the small communities within the forest.

The San Diego Natural History Museum and other partners recruited citizen scientists through posters placed in storefront windows and a series of “Have You Seen Me?” announcements in local newspapers.

“This project is providing researchers access to private lands across the San Bernardino Mountains,” says Kevin Clark, director of bioservices at the museum. “Without access to these properties, the data would not be possible to obtain.”

Service biologist Clark Winchell (right) and conservation intern Stella Yuan collect data on the San Bernardino flying squirrel's habitat in the San Bernadino National Forest. Credit: Joshua Ray/USFWS

The study began in October 2015, first training the citizen scientists about proper data collection, including collecting hair samples. They were also provided with remote video cameras.

Biologist Clark Winchell placed this trail camera, one of
several in locations throughout the San Berbardino
National Forest, in hopes of capturing images of flying
squirrels. Credit: Joshua Ray/USFWS

Using suet or birdseed as an attractant, the cameras use motion sensors triggered by the squirrels. Images of the squirrels with location data were uploaded by the citizen scientists to the web-based iNature database. The museum then collected the data for analysis.

The citizen scientists’ information is providing a glimpse into the lives of these elusive forest creatures.

“They are fairly social,” says Peggy Howe. “We’ve seen up to five on our deck where we have bird feeders. They hang upside down while they eat the bird seed.”

But from the Howe’s deck 40 feet above a canyon, they also have documented the squirrels feeding on lichens that grow on one of their cedar trees. The data also shows the squirrels are far more social and visible to people in the summer than the winter.

Having accurate, repeatable data collection is crucial to local land management agencies like the U.S. Forest Service and others interested in tracking the flying squirrels’ status over time.

VIDEO: Intern Stella Yuan talks about her first day in the
field surverying flying squirrel habitat. Credit: C. Medina-
Ontiveros/USFWS

“This collaborative effort has helped augment the Forest Service’s understanding of the San Bernardino flying squirrel,” says Robin Eliason, district wildlife biologist for the San Bernardino National Forest.

The project is expected to continue through September 2017, with the next phase focused on measuring the forest canopy and ground cover as they relate to occupancy by flying squirrels.

For Lilley, participation in the squirrel project also is providing hands-on science education for his two sons. “This is part of our homeschooling curriculum and the boys are learning responsibility and technical skills, including how to upload the remote camera video data,” Lilley says.

“There is more for my kids to learn as they prepare to continue participating in the next phase. My son and daughter met with researchers and learned about the different tools used to take habitat measurements.”

Service biologist Clark Winchell leads a team of interns and photographers into the San Bernardino National Forest to document the squirrel's habitat. Credit: Joshua Ray/USFWS

Two flying squirrels in their Alpine Zoo habitat.
Credit: Alpine Zoo

Clark Winchell, with the U.S. Fish and Wildlife Service’s Conservation Partnerships Program in Carlsbad, Calif., says citizen scientists help bring conservation into the public eye.

“Efforts like the squirrel program increase awareness of the natural world around us and give people a sense of ownership about species and habitats where they live,” he says.


The following agencies and organizations are supporting this program: U.S. Fish and Wildlife Service, San Diego Natural History Museum, U.S. Forest Service, University of California - San Diego and the Big Bear Alpine Zoo.

For more information about the SDNHM Citizen Science project please visit http://flyingsquirrels.sdnhm.org/ 

If you want to explore Citizen Science programs and projects in your area, check out https://www.citizenscience.gov/.


Jane Hendron is the public affairs officer for the Service's Carlsbad, Calif., Fish and Wildlife Office.