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You've Got Bats In Your Back Yard, And The Natural History Museum Wants Your Help Finding Them

A western red bat, one of many species that can be found in urban and suburban areas. (Courtesy of Ted Weller via LA County Natural History Museum)
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Bats may conjure images of dark, dank caves, but they can actually be found all over Los Angeles -- freeway underpasses, industrial hubs and, it turns out, in our own back yards.

That is in part why the Natural History Museum of L.A. County is asking for the public's help as part of its Backyard Bat Survey, which is billed as the first large-scale study of how the flying mammals make use of urban and suburban habitats. It would be difficult, the museum notes, for researchers to gain access to so much private property on their own.

Researchers hope that better data on these understudied habitats will help inform land planning and conservation decisions, and maybe inspire residents to take more interest in -- and better care of -- their local environment.

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Bats have long been the subject of myths and fears, and the COVID-19 pandemic has likely given people even more cause for concern, since many scientists agree that the new coronavirus crossed into humans from an animal -- most likely a bat.

But bats -- especially in L.A. -- don't deserve the scary reputation, according to Miguel Ordeñana, the museum's community science manager and leader of the survey. Quite the opposite: bats in Southern California are beneficial to the environment. For example, many eat mosquitos and other agricultural pests, saving farmers' money and killing dangerous disease carriers. Ordeñana also said that no bats have tested positive for the novel coronavirus in North America. And no need to worry about vampire bats here, either.

Ordeñana started studying urban bats in 2012 at the La Brea Tar Pits, the Natural History Museum, and the L.A. Zoo as a way to inspire interest in urban wildlife. He said his own inspiration for the project came after he discovered the first known photograph of P-22, the famous mountain lion in Griffith Park. In the past, wildlife studies have often overlooked the urban cores of cities such as Los Angeles. As an L.A. native, Ordeñana wanted to change that. Searching for a new project that would be accessible to city dwellers across the county, he set his sights on bats.

"Bats have the unique ability as the only mammals that can fly to be in any neighborhood, potentially. And so for me to design a project that was accessible, bats seemed like a perfect fit," Ordeñana told KPCC's news and culture show, Take Two, in a recent interview.

Ordeñana's preliminary results were enough to develop a pilot project, so in 2016 he began partnering with local community members to set up four acoustic detectors -- a recording device used to capture bats' ultrasonic calls, also known as echolocations -- that he would rotate on a monthly basis between a few private yards. In 2018, the Disney Conservation Fund helped expand the pilot project to 22 sites per year with 12 months of monitoring at each site around the county.

NHM's Miguel Ordeñana installing a bat acoustic detector at a home in the Westchester neighborhood of Los Angeles (near LAX). (Amy Jaecker-Jones/Natural History Museum of Los Angeles County)

Since the project's inception, the survey has detected 12 species of bats in backyards alone. To Ordeñana's surprise, the bats they found include urban-adapted species -- those that can roost under places such as freeway overpasses or roofs, as well as urban sensitive species -- and those who roost only in trees and need foliage to make their homes.

"These bats are showing that they're more resilient than we thought," Ordeñana said. "And it doesn't take a huge, expansive open space to keep them around. As long as we provide little chunks of green space -- whether they're community gardens or someone's backyard, that provides habitat for the food, which are insects -- they have a chance. And we want them to have a chance out here in L.A."

One of the best -- and most surprising -- examples of these bats' resilience in L.A. comes in the form of the western red bat. More sensitive than the urban adapted bats, western red bats need tree cover to feel comfortable making a home. According to Ordeñana, the Natural History Museum had recently restored and opened its own nature gardens in 2012. The gardens are located on the museum's campus south of downtown Los Angeles -- a densely populated urban area. But when Ordeñana put up his acoustic detectors, he recorded the western red bat's signature chirps.

To the human ear, a bat's echolocation calls can be almost impossible to hear due to their ultrasonic high pitch. However, when the recording is slowed down by almost 10 times, the chirps begin to sound like bird songs.

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(Sound clip: A recording of western red bat chirps, slowed by around 10 times. At slower playback speeds, the bats' echolocations become more distinguishable.)

Ordeñana says the bats' presence in the museum's nature gardens is an encouraging sign.

"If you build it, they will come. This little garden was previously a parking lot, a concrete parking lot, and not bat habitat at all," Ordeñana said. "So it's really exciting and inspiring for people who want to help out bats but feel like they can't, because they live in an apartment complex or some very urban setting. But really they can, and this is proof that they can help."


In September 2020, Disney renewed the project's funding. Now, Ordeñana and the Backyard Bat Survey team are asking for the community's help to find out where bats call home in Los Angeles. Residents can report bat sightings securely to the museum via email or by filling out a bat observation form. The locations will not be shared publicly, so as to protect the roosts and the baby bats that could be hiding inside.

Tracking bats' roosts is key to the species' future in L.A., Ordeñana said. "By figuring out and mapping where roosts are in L.A., that's a huge step forward in understanding what natural and human structures bats are relying on to survive and persist here in the L.A. area."

Unfortunately, the recent stay-at-home orders have slowed Ordeñana's efforts to install more bat detectors throughout the city and further delay his ability to interact with families, schools and libraries in person.

"This is disappointing from a science and data collection standpoint, but more disappointing that these communities won't have the same opportunities for engagement as neighboring areas with bat detectors," he said. "The areas that I am trying to fill in are neighborhoods that currently do not have strong relationships with the museum, and this is an opportunity to begin to change that."

Eventually though, with community input, Ordeñana said he hopes to better guide city policies that could affect the bats' habitats -- for example, advising the city on which buildings get torn down or how street trees are trimmed.

For Ordeñana, the community science portion of the project is of the utmost importance. He said that including the public and giving them a seat at the table is critical to sustainable conservation, and is one of the reasons he has focused his research around schools and other community centers.

Ordeñana said that the old wildlife research model -- collecting data, writing a report, and then leaving -- left many communities without the tools or information to protect endangered species. Instead, Ordeñana wants to engage the local community, answer their most pressing questions and help them become stewards of their local environment.


To participate in the Backyard Bat Survey's project and report roosts or bat sightings, email the Natural History Museum of Los Angeles County at or use the museum's bat observation form. You can also visit the Backyard Bat Survey webpage or go to and search "Backyard Bats."

Correction: This story originally misstated several specifics about the timing and locations of the survey and the original pilot project. LAist regrets the error.

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