News Release

Teaming Up to Sleuth Out the Mysteries of Marin’s Bats

Subscribe RSS Icon | What is RSS
Date: July 17, 2018
Contact: John A. Dell'Osso, 415-464-5135
Contact: Lisette Arellano, 415-426-5254

Countywide Bat Monitoring Project Underway

Marin County, CA - Seldom seen and often misunderstood, bats are actually tremendously important parts of our communities, helping keep many insects—such as mosquitoes and garden pests—under control. So little is known about our local bats, however, that it's like we have these amazing neighbors whom we've never actually met.

For the first time, the Marin County Bat Monitoring Project is going countywide to uncover some of the many mysteries surrounding the region's bats. What species live where? Where do they hunt? Where do they sleep? Where do they raise their young? How might things like habitat loss or change be affecting the places they depend upon and what can we do to help them thrive?

The US Geological Survey (USGS) Western Ecological Research Center, Point Reyes National Seashore, and One Tam partners are embarking on their second year of the project, which is expanding to include the whole county and adding new surveys that will tell us about where our bats like to live.

"Despite how important these creatures are, we actually know very little about them. So, getting even basic information is essential for our partner agencies who are trying to conserve bat populations on their lands," says Gabriel Reyes, USGS Project Manager. "Tracking them across a larger range and over multiple years will also allow us to see and share the story of their lives as it unfolds for us over time."

In June and July, microphones that can pick up the high frequency noises bats make as they hunt at night are being placed on the tops of tall poles at thirty-one park and open space sites around Marin. While these sounds are out of the range of human hearing, the bat detectors allow us to record and visualize their vocalizations. Different bats make different sounds, so these recordings will tell us what species are feeding or traveling in these protected areas. Last year's surveys detected thirteen different kinds of bats, with seven or eight different species recorded at some sites.

Starting at the end of July, bats caught in mist nets as they are hunting along state and national park creeks will be fitted with small radio telemetry tags and then tracked back to where they go to rest during the day. The tags fall off after a week or two, so there is a limited window of time to locate bats and collect data. Biologists will take advantage of that time to return and count the number of bats that emerge at dusk and to survey the kinds of structures, trees, and other vegetation that make up the roosting habitats that they prefer.

This research may also help inform how bats in Marin County respond to White-nose Syndrome, a deadly fungal disease that hits bats as they hibernate. The disease was recently found in Washington State, but it has not yet been detected in this area. Finding out more about where bats in Marin County roost during the winter, and if they hibernate, may illuminate how local bat populations will be impacted if White-nose Syndrome is introduced here.

Point Reyes National Seashore Wildlife Ecologist Dave Press adds, "In addition to giving us great information about our local bats, all of this will also go into a nationwide database run by the North American Bat Monitoring Program so that what we learn contributes to our broader understanding of what's going on with bats across the country."

Given that many bat species in the United States are in severe decline and several are listed as endangered, coupled with the growing threat from White-nose Syndrome, contributing to the bigger picture of what's happening to them is especially critical.

To learn more please see or come hear USGS biologist Gabe Reyes's talk about the project and Marin's bats at the San Rafael Public Library on Thursday, August 23, from 6:30 pm to 7:30 pm. You can register for this event by calling 415-485-3321.

About the Project Partners:

U.S. Geological Survey, Western Ecological Research Center
USGS provides science for a changing world. Visit, and follow us on Twitter @USGS and our other social media channels.

One Tam is a partnership of:

California State Parks
The California State Parks are dedicated to providing for the health, inspiration and education of the people of California by helping to preserve the state's biological diversity, protecting its most valued natural and cultural resources, and creating opportunities for high-quality outdoor recreation.

Golden Gate National Parks Conservancy
The Golden Gate National Parks Conservancy is the nonprofit membership organization that supports the Golden Gate Recreation Area. Since 1981, the Parks Conservancy has provided support for site transformations, trail improvements, habitat restoration, research and conservation, volunteer and youth engagement, and interpretive and educational programs. In Marin, the Conservancy has restored habitat and trails, engaged youth and volunteers, and managed a variety of wildlife and plant monitoring programs. Learn more at

Marin County Parks
Marin County Parks offers an extensive system of regional and community parks, open space preserves, and trails for public use and enjoyment. It is dedicated to educating, inspiring, and engaging the people of Marin in the shared commitment of preserving, protecting, and enriching the natural beauty of Marin's parks and open spaces, and providing recreational opportunities for the enjoyment of all generations.

Marin Municipal Water District
Marin Municipal Water District is a public utility providing water to 186,000 people in south and central Marin County, and managing 21,635 acres of watershed lands open to public use. In operation since 1912, MMWD is the oldest municipal water district in California. The district's mission is to manage natural resources in a sustainable manner and to provide customers with reliable, high-quality water at a reasonable price.

National Park Service
The National Park Service has more than 20,000 National Park Service employees care for America's 417 national parks and work with communities across the nation to help preserve local history and create close-to-home recreational opportunities. Learn more at


Logos for the USGS, One Tam, California State Parks, Golden Gate National Parks Conservancy, Marin County Parks, Marin Municipal Water District, and the National Park Service. A black square with wavy white lines next to the all-cap letters USGS. The words One Tam in blue capital letters.A cartoon of a grizzly bear on a golden field inside of a thick blue circle. The blue circle contains the words California State Parks.The words Golden Gate National Parks Conservancy in white all-cap letters on a black background within an orange rectangleThe words Marin County Parks Preservation Recreation above a cartoon of a silhouette of a hawk on a fence post with a sun just above the horizon in the background.A circle with a blue rim containing green lines depicting a mountain and hills and blue lines depicting water above the words Marin Municipal Water District. The National Park Service Arrowhead logo, which is an arrowhead with a brown background containing the words National Park Service and silhouettes of a mountain, a sequoia tree, a lake, and a bison.

Last updated: July 19, 2018

Contact the Park

Mailing Address:

1 Bear Valley Road
Point Reyes Station, CA 94956


(415) 464-5100
This number will initially be answered by an automated attendant, from which one can opt to access a name directory, listen to recorded information about the park (i.e., directions to the park; visitor center hours of operation; weather forecast; fire danger information; shuttle bus system status; wildlife updates; ranger-led programs; seasonal events; etc.), or speak with a ranger. Please note that if you are calling between 4:30 pm and 10 am, park staff may not be available to answer your call.

Contact Us