More important than breaking records, we had the opportunity to analyze data on a species-by-species basis to shed light on territory re-use, non-breeding pairs, nest takeovers, nest switches (takeovers by other species), and more. The goal of the study is to understand the year-to-year trends and to discover the forces at work involving our local raptors in the Los Angeles area. Apex predators play an important role in the ecosystem, especially in our complex urban setting where human influences can alter balances. What better place than Los Angeles to study urban raptors?

In late September, the LA Raptor Study 2024 Final Report was presented to a well-attended audience via Zoom. The Study represents the only comprehensive dataset of an entire breeding raptor community within the urban core of Los Angeles, per Dr. Dan Cooper (Cooper Ecological Monitoring, Inc.), who directed the launch of the Study in 2017.

Nurit Katz, the Study’s Outreach Coordinator, has elevated communication and education capabilities with our volunteers and the public since 2022. Nurit was a raptor study volunteer, monitoring nests prior to her taking on her current role, and she is also employed as UCLA’s Chief Sustainability Officer.

The study has become a recognized model for “community science” within Los Angeles, with clear scientific goals and plethora of data being collected by community scientist volunteers who undergo training on scientific methods.

Apply to Volunteer in 2025

Details for participating in the study are discussed on FoGP’s “Raptor Study & Resources” webpage where you can also find a link to a Volunteer Application. In January, registered volunteers are invited to a virtual training session and a field training workshop held in early February. Nest assignments are then made. Dan, Nurit, and myself also help orient new volunteers at their assigned nest sites.

Since Cooper’s Hawks are late-nesters and present special challenges in tracking, a second virtual session and field training are offered specifically for this species in April. Cooper’s Hawk nest assignments are made for ambitious, willing volunteers, and nearly all volunteers want one!

Study Result Highlights in 2024

650 raptor territories were rechecked or discovered across the study area, representing 239 Cooper’s territories (vs. 222 in 2023), 215 Red-tailed Hawk territories (vs. 184 in 2023), 57 Red-shouldered Hawk territories (vs. 55 in 2023), 105 Great Horned Owl territories (vs. 84 in 2023), as well as a handful of territories of American Kestrel, Peregrine Falcon, Barn Owl and Western Screech-owl.

While not all of these territories were found to be active in 2024, the numbers continue to closely reflect the maximum number of territories in the study area, thanks to increased effort and our growing knowledge of local species ecology. The study puts focus on the territories of breeding pairs which, for the most part, mate for life, but don’t necessarily use the same nests from year to year.

Fledge Rates

We define Fledge Rate results as fledged nests for territories tracked; the fledge rate of active nests, on the other hand, is extremely high, with few failures once birds start incubating. Convergence of the Fledge Rate this year for the three focal hawk species is interesting and unexpected, considering they were quite different in the previous few years:

• Red-tailed Hawk: 127 nests fledged from 169 active territories (75%). This fledging rate saw a return to average after the higher rates of 2020 and 2021 and lower rates in 2022 and 2023.

• Cooper’s Hawk: 88 nests fledged from 113 active territories (78%). This rate of success was slightly below the average across the past five years, up from the last two years.

• Red-shouldered Hawk: 27 nests fledged from 36 active territories (75%). This proportion is higher than the prior two years and the 5-year average, but lower than in 2020.

• Great Horned Owl: The analysis for this species changed this year, because we added new territories based upon more than only active nests found, ­such as pairs that duet. We found that 40 nests fledged from 58 territories, but any comparison to previous years would be invalid.

Territory Re-occupancy

Red-tailed Hawks kept their amazing and steady territory re-occupancy rate of 80%. The other two hawk species’ re-occupancy rates have been more variable over the years of study. Red-shouldered Hawks were around 75% in 2024. The lowest rates were for Cooper’s Hawks at roughly 65%, which is well above the previous two-year 50% average territory re-occupancy rate. Only these hawk species were included in this analysis. There are plans to dig deeper into the data to explore nest structure re-use, in addition to focusing on territory re-use.

Nest Productivity

While there was a significant increase across all four major species in the total number of fledged young, nest productivity rate is measured as the mean number of chicks hatched from successful active nests (with failed/abandoned nests excluded). Interestingly, this metric peaked in 2019 across our four species. There is no explanation. It is possible that two very wet winters was not enough to overcome the previous drought trend in place, and we continue to explore possible correlations with seasonal weather.

Over the study period (2017-2024), mean nest productivity number (chicks per nest) varied in a fairly tight range of 1.8 for Red-shouldered Hawks to a high of 2.5 for Cooper’s Hawks.

Our Special Species

There is limited data from the study on the rarer local raptor species, including American Kestrel, Peregrine Falcon and Western Screech-owl.

The study closely tracks one peregrine pair in Griffith Park. Two other peregrine nest locations were confirmed on top of high buildings this year where juvenile rescues took place. Several other tall structures are also suspected host sites for nesting, but collecting data is difficult due to building management challenges. We plan to put more effort to following these peregrines in coming years.

Cavity-nesting American Kestrels also prove challenging, but one residential-area nest in Boyle Heights was monitored and another territory in Sepulveda Basin was confirmed with four post-fledged juveniles observed.

Work done by students under the UCLA Institute of Environment and Sustainability Senior Practicum, with FoGP as their client, addressed breeding owl species including Barn Owls and Western Screech-owls. Students successfully contributed with nocturnal field surveys and predictive distribution modeling. More detail is available on FoGP’s raptor webpage.

Nest Disturbance and Tree Trimming

A new focus of the study involves documenting nest disturbances such as nests lost to wind, tree-trimming or trees being chopped down. It is illegal to trim out nests even when it is done between nesting seasons. It is also illegal to disturb active nests in any manner which may adversely affect reproductive success. We have observed that the destruction of nests is often unintentional on the part of residents.

In 2024, to address the significant trimming issues observed, we created signs to place on accessible nest trees. The signs include information about applicable laws protecting nests. Template letters were also created to inform homeowners and area residents of nests on their properties. These measures represent a proactive educational approach to prevent loss of nests.

Another disturbance involves loss of raptors through secondary poisoning by rodenticides. We hope that the California bans on two classes of anticoagulants will alleviate the senseless death of raptors that ironically serve a vital role in rodent control. FoGP and many other organizations have fought hard for these legislative actions; we’re finally nearing the goal line.

The Raptor Study family of participants celebrated a fantastic year of accomplishments at the Volunteer Appreciation Dinner held in Griffith Park this fall. FoGP thanks our volunteers, our talented science team, and the public agencies that provided access and services, along with L.A. residents who provided so many great tips! Let’s keep up the momentum!

~ Gerry Hans
photo: Gerry Hans

Hummingbirds are residents of Griffith Park and can be seen flying in many areas. Hummingbirds are among the smallest birds found in our world and have great acrobatic skills, hovering in midair and even flying backwards.

Because of their small size, hummingbirds burn calories very quickly and require constant feeding to ensure they have energy for their active lifestyle. A hummingbird’s diet consists of protein provided by insects and carbohydrates provided by flower nectar. Hummingbirds are very selective of the flowers they visit and many plants have adapted their flowers to cater to the hummingbirds. Hummingbirds and plants engage in a mutualistic relationship, evolved over time, in which the flowers get pollination services and the hummingbird gets a valuable meal.

The flowers that are most attractive to hummingbirds have colors of red, orange, and yellow. Hummingbirds do not use smell to discern flower preferences, but can detect dangerous insects in order to avoid them by sensing their chemicals. Because hummingbirds can hover in midair, their preferred flowers will lack a landing platform and are suspended in the air away from the plant to ensure a clear line of sight by the bird.

One of the best ways for people to help hummingbirds is to incorporate plants in their garden space with flowers that specifically cater to the birds. Plastic or glass nectar feeders are not recommended because they can easily transfer infections and pathogens from one hummingbird to another.

If you wish to view hummingbirds while hiking, all you need to do is sit in close proximity to a plant that is blooming and avoid making sudden and quick movements. ­In time, hummingbirds will arrive to drink from the flowers – and you will have a front row seat.

­~Jorge Ochoa, FoGP Advisory Board Member

Ochoa is an associate professor of horticulture at Long Beach City College.
He often leads FoGP walks through Griffith Park, and occasionally
lectures on the fauna and flora found throughout the Park.­

You’ll probably hear its distinct voice before you see the elusive Nuttall’s woodpecker. The call is a loud rattling with just a couple notes that most new birders find easy to learn. Other times you may first hear them drilling or “drumming” into bark or dead wood. The reason Nuttall’s do this varies. They could be looking for food as they poke under the bark of trees; however, they also could be marking their territory or punching out a cavity since they are cavity-nesters.

A pair of Nuttall’s will drill a new nest each year, often into soft, dead wood. Their favorite trees in Griffith Park are elderberry, oak and sycamore. They line their nests with wood chips to cradle the eggs. These cavity nests create a high level of security for the brood. While the parents share the egg incubation tasks, the male is usually saddled with the construction job. When they’re finished rearing the chicks, other species, such as Griffith Park’s many Bewick’s wrens and the oak titmouse, will use the cavities the next season.

Nuttall’s favor the oak woodland habitat of the Park where they find and devour ants, bugs, various creepy crawlers, and also berries, fruit and seeds. Harvesting from poison oak is not a problem!

There is little chance of confusing this species with the Park’s larger, gregarious acorn woodpecker. Acorns have more of a laughing call and are everywhere in Griffith Park. To hear and see a Nutttall’s is indeed very special!

This woodpecker species gets its name from a celebrated British naturalist, Thomas Nuttall (1785-1851). Although not formally trained as an ornithologist, he spent much of his career in America following the paths of pioneers such as Lewis and Clark. He is credited with discovery of many flora and avian species. However, it was an associate collecting specimens for Nuttall in 1843 who brought this small woodpecker from the Wild West to England.

This limited-range species doesn’t stray from its year-round residency in much of the western half of California, and slightly extending into Baja. Nuttall’s are not found in the rest of the country, nor anywhere else in the world. Very Californian!

Not sure if what you are hearing is a Nuttall’s woodpecker? We recommend the free Merlin bird id app for your smartphone! The sound identification feature works quite well.

~Gerry Hans, FoGP President

Griffith Park serves as home to a large number of native plants and animals. Over thousands of years, the animals and plants have established mutualistic relationships in which they help each other and where both benefit.

One such relationship includes the Coast Live Oak, found throughout the canyons of the Park, and woodpeckers. Oaks produce thousands of seed known as acorns every year. Acorns drop to the ground when they reach maturity and are ready to germinate. Acorns that remain under the canopy and shade of the parent tree will have very little chance of surviving.

The oak tree wants to disperse its acorns as far as possible to give young seedlings an opportunity to find an open space for germinating and growing into a mighty oak. To disperse its seeds, oak trees hire woodpeckers.

Each acorn is loaded with carbohydrates a perfect meal for a hungry woodpecker. Woodpeckers will eat many acorns on the spot but when they’ve had their fill, they will carry many of the acorns away from the tree and store them for eating later through the fall, winter and spring seasons.

Woodpeckers store acorns in a granary which they typically make out of dead trees. When not harvesting and storing acorns, woodpeckers spend many hours tending their stored acorns and protecting it from thieving animals.

But not all acorns stay in the granary. Untended acorns often fall from its storage gallery, dropping to the ground, thereby giving seedlings inside the acorn opportunities to survive and germinate. Stolen acorns are also dropped by larcenous animals during a possible squabble with the protective woodpecker.

From the thousands of acorns that are produced by oak trees in Griffith Park each year, a very large number of them will end up in the stomach of a hungry animal and a very small amount will be lucky to survive to germinate and grow into a tree. In the mutualistic relationship between the oaks and the woodpeckers, the trees benefit from seed dispersal and the animal benefits with a nutritious meal.

What could happen when people interfere with this plant and animal relations?

What happens when for the safety of the public, large dead trees are removed from the Park and the woodpeckers are left with no trees to build their granaries?

The answer is as amazing as the wildlife that calls Griffith Park their home. Wildlife has adapted, reimagined and figured out how to take advantage and use the few resources that people have left for them. For example, woodpeckers are now using human-created traffic sign posts as granaries. Almost all the traffic signs along Vermont Ave are now granaries for woodpeckers and are being filled with acorns.

Wildlife in an urban environment must adapt in order to survive and the modern thinking woodpeckers of Griffith Park have abandoned the wooden granary and replaced them with steel cages which offer better protection for their valuable food. But what of dispersing oak seeds for future generations?

It took people just a few years to break the oak tree-woodpecker relationship that was in place for thousands of years. The consequences of the human these actions toward the wildlife in Griffith Park will be seen many years from now.

~Jorge Ochoa, LBCC
Photos courtesy: Jorge Ochoa

Over the six years of the Los Angeles Raptor Study, a community science supported by Friends of Griffith Park, more than 600 raptor nests have been found in locations that range from natural areas in open space to trees right next to the freeway. In our dense urban environment, raptors are finding ways to make their home in backyards, and even on buildings in busy downtown areas.

The study was first launched in 2017 as Griffith Park Raptor Survey and has expanded since then. More than 100 trained study volunteers monitor these nests in the Spring, tracking whether they are successful and how many chicks they have. “This data-gathering is vital to biologists because it represents a specific, comprehensive dataset of raptor habits over multiple years,” says Dan Cooper, the Study Director, who also serves as Senior Conservation Biologist for the Resource Conservation District of the Santa Monica Mountains.

The life of our urban raptors in Los Angeles can be dangerous and difficult. Vehicle and building strikes, poisoning from rodenticides, disturbance from noisy construction projects, tree trimming and illegal nest removal, even diseases carried by pigeons, are all threats our hawks and owls have to navigate. On June 15, Courtney McCammon, Volunteer Coordinator for the Los Angeles Raptor Study, and Urban Ecologist for Recreation and Parks, got a call from Frances Tait, one of the Raptor Study volunteers. While walking her daughter to school, her husband Asa had found an injured juvenile Red-tailed hawk on a freeway overpass in Hollywood. Courtney was able to capture the hawk, and Outreach Coordinator Nurit Katz transported it to Ojai Raptor Center, a specialized rehabilitation center in Ojai. “We knew the bird would be in good hands, but we were very anxious for updates,” Tait explained to the Eastsider, who covered the rescue.

The young hawk had suffered a right femoral fracture, bilateral coracosternal luxations (coracoid dislocated from the sternum) and mild right eye trauma, likely from a vehicle strike. Many rescued raptors do not survive because the injuries are too severe. In this case, with veterinary care and after weeks of rehabilitation, the young Red-tailed hawk was fully healed and able to be released. In mid-August volunteers and raptor study staff gathered and released the hawk in a park not far from its nest territory, one of the most urban nests in the study, located in a tree right at a freeway ramp, surrounded by rushing traffic.

Some nests are found by the study staff who track flying hawks back to where the nests are located, but for many nests the study relies on community science data from iNaturalist and ebird, and tips from neighbors who have noticed the raptors or their nests and hear about the study via NextDoor or other social media outreach. Many residents in LA walk their neighborhoods every day without realizing there is a hawk or owl raising its young right above their heads, but for those who do notice, they often get excited and even connect with the raptor family long term, watching their progression over the years. Hawks and owls often pair for life and will nest in the same territory year after year, and often in the same nest location. One neighbor fondly called his neighborhood Cooper’s Hawk Anderson, for Anderson Cooper. Study staff have heard all sorts of interesting stories from residents, from hawks bathing in pools and fountains and accidentally flying inside the house, to a young Cooper’s Hawk plucking a towel or playing with a pine cone as it practices hunting.

In July, the study Outreach Coordinator received frantic calls from multiple residents of a Mt. Washington neighborhood. The residents had observed a long standing pair of Red-tailed hawks nesting on the street for over 10 years, watching multiple generations of young hawks take flight, and considered the hawks part of their community. A tree trimmer had come in and heavily trimmed the nest tree during nesting season, which is illegal, and ended up removing the nest despite neighbors trying to stop them. The neighbors were distraught and the hawk family was clearly distressed. Raptor Study staff were able to report the violation to the CA Department of Fish and Wildlife, and educate residents about the Cal Tip hotline for future. If you ever see a violation in progress you can call 1-888-334-CALTIP (888-334-2258), 24 hours a day, seven days a week. To avoid these kinds of problems in the future, study staff also assisted in teaching a workshop for arborists across California on Tree Care for Birds and Wildlife. Helpful resources can be found at treecareforbirds.com.

Through the raptor study we continue to learn how these important indicator species are adapting to our urban environment. Continuing this work to better understand our urban ecology, and ensuring their survival, takes a village. Although human activity causes environmental harm, people can also work together to support raptors and other wildlife. Not trimming during nesting season, making sure not to use rodenticides, reporting illegal activity, taking care not to disturb nesting birds, and contacting a wildlife rehabilitator if you see injured wildlife, can all help these incredible birds have a better chance of survival. Educate your friends and neighbors and help build a community that is more supportive of raptors and biodiversity.

You can help the Raptor Study by reporting nests or frequent raptor activity in your neighborhood to raptors@friendsofgriffithpark.org or to Outreach Coordinator Nurit Katz at 818-384-9493. You can also contact Nurit by text or call for assistance if you are unable to transport an injured raptor.

If you would like to get more involved — volunteer for the 2023 season. You can fill out a Los Angeles Raptor Study application. Volunteering requires attending a training workshop and then checking an assigned nest once every two weeks.

(This article originally appeared in the LA Audubon’s Sept/Oct 2022 Western Tanager publication.)

~Nurit Katz, Outreach Coordinator, Los Angeles Raptor Study
Photo, courtesy Asa Shumskas-Tait

Background
Launched as the “Griffith Park Raptor Survey” in 2017, we renamed our effort the “Los Angeles Raptor Study” in 2021 to reflect the larger current study area now covering most of Los Angeles exclusive of the north and west San Fernando Valley, South Los Angeles, and the Harbor area. By documenting and tracking raptor nests across Los Angeles, we hope to understand how ecological dynamics change from year to year in the natural and built areas of Los Angeles, in particular how human activity is impacting wildlife here. While a handful of Los Angeles area raptor nesting sites had been documented in the past, the data contained in our annual summary reports represent the first comprehensive dataset of an entire raptor community in the urban core of Los Angeles.

In 2022, we continued monitoring within our 2021 study area (including Sepulveda Basin, Baldwin Hills, and Glendale), and again increased the number of monitored territories for the sixth year of the Griffith Park Nesting Raptor Survey.

As in prior years, we were able to confirm as active many territories by the presence of recently-fledged young and recently-used nests (particularly Cooper’s Hawks), using clues learned while more closely observing known nests.

We again confirmed no active Western Screech-owl or Barn Owl nests, and while we confirmed a single Peregrine Falcon nest, we confirmed no nests of American Kestrel in 2022. As in 2021, these numbers (at least the diurnal species) more closely reflect actual numbers of active nests in the study than those in surveys prior to 2020 when our efforts reflected lower numbers.

Location
The Study Area originally centered on Griffith Park, was expanded in 2020 to include additional portions of the San Fernando Valley and coastal plain that were not covered in prior years. As of 2022, the Study Area extends to the 405 Freeway/Sepulveda Pass in the west (with an extension to include Sepulveda Basin), Sherman Way/
Vanowen Blvd. in the north, Slauson Ave. in the south, and East Los Angeles in the east. A handful of raptor nests just outside this area were monitored by volunteers (e.g., Encino, Pasadena, Calabasas), but we did not specifically search for nests in these areas.

Nest Use, Re-use and Success
By 2022, our rate of finding new nests within the study area has slowed from 2020 and 2021, such that we added new nests in 2022 as follows: Red-tailed Hawk (6), Red-shouldered Hawk (4), Cooper’s Hawk (26), and Great Horned Owl (7). These numbers don’t include new (for 2022) territories where nests were suspected, or known territories where we had pairs (or even juveniles) in the past but only discovered physical nests in 2022. Looking at territories (some of which had nests, but not all), we located additional territories for 27 new Cooper’s Hawk pairs, 13 for Great Horned Owl, 9 for Red-tailed Hawk, and 5 for Red-shouldered Hawk (not including species switches, such as an owl taking over a hawk nest). This may be contrasted with 2021, when we found 35 new Red-tail nests alone.

This year (2022), we re-analyzed our data from all six years of territory re-use and success for the three focal hawk species and for Great Horned Owl in order to present these results in a more consistent, quantitative manner. Importantly, our nest-searching effort increased greatly starting in 2020, so the years 2017-19 may be thought of as preliminary compared to the years 2020-22. In particular, we searched for and located few urban Cooper’s Hawk nests in the San Fernando Valley or mid-City area prior to 2020, before we learned some of the tricks to finding them there.

We intend to analyze nest structure re-use in the future: as the multiple years of the study are presenting unexpected analytical challenges; for example, determining how to best consider a nest structure re-used, particularly if a pair skipped using it for a year or more, then returned to use it, re-built nests, and those built a few feet away in the same tree.

Looking at each species, we found that Red-tailed Hawks maintained fewer active territories in 2022 than the year prior, and 2022 saw the fewest fledged nests over the past three years, with several dozen pairs either absent from known territories, or abandoning nests midway through the season.

Cooper’s Hawks also maintained fewer territories in 2022 than in the two prior years, and fledged fewer young than in 2021, but proportionately more of these 2022 nests fledged young than in prior years.

For Red-shouldered Hawk, 2022 saw more active territories, but roughly the same number of active nests fledged young, resulting in proportionately lower fledging rate per nest.

For Great Horned Owl, 29 active territories were monitored (the most since the start of the project), and as in prior years, many (28) were deemed to have fledged. However, most owl territories were identified by the presence of young; we did not attempt to search for owls during the study.

Nest Productivity — Factoring in Precipitation
Across all focal species, nest productivity peaked in 2020, but the differences between years was slight, and likely not statistically significant. Cooper’s Hawk consistently fledged the highest mean number of chicks per successful nest, with an average of 2.43 young from 2018-2022. Red-tailed Hawk had the next-highest rate (1.92), followed by Great Horned Owl (1.89), and Red-shouldered Hawk (1.6).

There are many ways to measure nest productivity — one is the proportion of single-chick nests (nests where the maximum number of chicks was believed to be just one, versus all other nests where chicks were produced), which could indicate a shortage of food that year. Assuming that Red-tailed Hawks would be most sensitive to change in precipitation (since they take more native prey species from wildland areas than, say, Cooper’s Hawk, which are well-distributed in urban areas), we examined the relationship between precipitation the prior year, and the proportion of 1-chick nests in Red-tailed Hawk.

Evidently, the years following the driest winters (i.e., 2018, 2021 and 2022) all saw >20% of Red-tailed Hawk nests with single chicks (no such pattern was observed with Cooper’s Hawks), which conforms to recent findings looking at precipitation and Northern Goshawk (Accipiter gentilis) nests.

Failed Nests
As in past years, it may be instructive to review why the few failed nests did so. We summarize all Red-tailed Hawk nests believed to have failed, that were never initiated (within known territories), and that were apparently abandoned mid-season. Unlike last year, when three Red-tailed Hawk pairs had their nest trees removed, only one Red-tailed Hawk nest tree had been trimmed prior to the start of the 2022 season.

We were also notified of the illegal trimming and removal of a long-standing Red-tailed Hawk nest in the Mt. Washington area shortly after fledging:and of another trimming incident involving an active Cooper’s Hawk nest in Los Feliz:

Raptor Mortality, Rescue, and Rehabilitation
One of the leading causes of death for raptors in urban areas are collisions.

Interested in volunteering for the 2023 LA Raptor Study?
We will need community scientists to help monitor nests.
2022 LA Raptor Study Results

~Original report by Dan Cooper, Courtney McCammon, and Nurit Katz

As Gerry points out, it’s hard to keep Jorge away from Griffith Park, and we’re happy he’s always willing to act as a host on these hikes.

The full video can be viewed here.

This year, FoGP is helping fund a project that will shed a light on one of the most unfairly maligned creatures around — our urban bats.

“I like animals that are misunderstood and a little controversial,” says FoGP Board Member Miguel Ordeñana who is overseeing the project through the Natural History Museum of Los Angeles County. “Being able to fly, bats are great to study in the dense urban core because they aren’t hampered by obstacles on the ground like other terrestrial creatures such as bobcats, coyotes and even mountain lions.”

Starting small in 2017 with only four bat detectors, the Backyard Bat Survey now employs 30 devices in various sites around the Los Angeles basin; this year the small unobtrusive boxes have been placed along the Los Angeles River from Griffith Park to South Los Angeles. In the Park, detectors have been set up near water sources (i.e., Lake Hollywood and near the L.A. River) that often attract bats.

Some sites, especially in densely populated neighborhoods, are in residential backyards — places where scientific research isn’t typically done. Usually, studies are conducted in natural wilderness areas which, explains Ordeñana, doesn’t give researchers an accurate portrait of bat species. You have to go where the bats go — and many of them are using habitat and resources in L.A.’s urban core. “A lot of people assume they don’t have bats on their property,” says Ordeñana. “They tell us, “We never see them,’ but these detectors tell a different story.”

Unlike a camera trap that snaps a photo of the animal, a bat detector records high-frequency noises; each bat species has a specific noise patterns of echolocation so it’s easy for researchers to determine which species was flittering overhead. Data collected so far shows numerous instances of bats co-existing near human populations. They are found flying through communities and roosting in man-made structures.

Enlisting community scientists to open up their backyards for a bat detector provides richer data which can, among other goals, help guide land planning as well as spark enthusiasm for the natural world. “Previous hosts told us they enjoyed being a community scientist,” says Ordeñana. “They liked learning about local wildlife and, for families with young children, the experience exposed them to a potential career or lifelong field of study.”

Why bats?

Bats play an important role in the world’s ecosystems; they pollinate, disperse seeds and keep insect levels at a sustainable number. In Southern California, the majority of bat species are insectivorous and are amazingly effective in pest control. Consider this: bat colonies can eat a million insects every night and one of their favorite snacks is mosquitos. These buzzing insects are not only a nuisance when you get bit, but they also transfer diseases, some deadly. Additionally, bats save the agricultural industry billions of dollars a year in pesticide costs and crop damage.

Finally, bats are good indicators of environmental health. For instance, a species like the hoary bat only roost in foliage; their presence or absence reveals a lot about the habitat quality. Of the 12 bat species that have been detected in the study, four of them are California Species of Special Concern. The bat most common in the L.A. Basin: the Mexican free-tailed.

In addition to filling major data gaps for the L.A. area, the data collected in this project will be incorporated into the Bat Acoustic Monitoring Portal (BatAMP), providing insights for the broader bat research community to develop an improved understanding of seasonal and migratory patterns across North America.

Have you seen bats emerging from structures around your neighborhood? The Natural History Museum wants to know! Currently they’re mapping bat roosts; if you see these winged mammals heading out for the night, please email them at bats@nhm.org.

Bats are most active on warm nights. Head out about 30 minutes before dusk and check out palm trees, old or dead trees, rock outcroppings as well as human structures like houses, underpasses and bridges. Stay your distance — about 15 feet — as you quietly observe.

~ Brenda Rees, FoGP Board Member

photos: courtesy Natural History Museum of Los Angeles https://nhm.org/

Ten years ago in 2012, when mountain lion P-22 was discovered haunting the hills of Griffith Park, this wasn’t just another example of nature seeping through the cracks in the big city. This story was different for me because here was a big cat trying to find his place in the world, going against the odds to carve out a territory and create a life to call his own.

Reading about his amazing journey reminded me of my own introduction to life in Los Angeles.

As a Minnesota-born and raised girl, coming to California was a leap of faith. I was young and out of college; I had a job secured and a place to live in Venice with a ragtag group of wannabe actors. But Los Angeles, the territory, was immense. My first week here, a group of us went up to the Griffith Observatory at night to see the city lights twinkling to San Pedro and beyond. I was overwhelmed. And scared. How will I ever find anything in this place!? How will I ever find me?

Armed with a tattered, hand-me-down copy of the Thomas Brothers Guide Book (this was the “80s after all!), I memorized street names (mispronouncing La Cienega as The Cigar Box), learned the freeway system, scribbled shortcuts on post-it notes. I got lost numerous times, retraced my path and kept plugging away through frustrations, banging my head on the steering wheel and not understanding that the 101 N often travels west and the 101 S is frequently eastbound.

P-22 didn’t have the luxury of a Thomas Brothers. He left the Santa Monica Mountains and survived two dangerous freeway crossings by following some internal compass that led him to a place that offered food, water and shelter. Arriving as a young cougar, he had the energy to quickly settle down and get to work to make Griffith Park his home.

I imagine P-22’s first days in Griffith Park were spent constantly looking over his shoulder, sniffing the ground for other mountain lions, learning places where humans congregate, discovering the best techniques to hunt deer. How many times did he fail? How many times did he sulk back to his lair empty handed (or empty-pawed)?

Those early years in Los Angeles, I often felt like I was failing, frustrated and far away from home. In addition to learning the territory, I was also navigating the world of work; with each career and apartment move, I wondered, “Am I doing the right thing?” I wanted to discover what I really wanted to do with my life. To find a purpose.

I may have felt alone, but I was lucky to have had good friends on my side. Friends who picked me up from a freeway off-ramp when my car blew up. Helped me understand the psychology of co-workers. Offered solid advice on the numerous blind dates I went on. And lucky for P-22, he too, had — and still has — friends.

He’s got biologists who track his movements and keep him healthy when he gets sick. He’s got folks infusing him with a wise-cracking persona and social media account so he can be a spokescat for his kin and illuminate the plight of mountain lions everywhere. He’s got world-class photographers snapping his pix and displaying his likeness on magazine covers like a true Hollywood glamour star. He’s got fans around the world and there’s even a movie made about him.

OK, here’s where my story differs from P-22. There’s no B. Rees flick or technology monitoring my every movement (wait! I do own a Smart phone:hmmm:.)

But at the end of the day, when the golden sun is setting into the shimmering Pacific Ocean, I’m content in my warm house and the sweet life I managed to carve out here in Los Angeles; it took years to find purpose, love, shelter, friends and family. But well worth it.

On starry evenings, I imagine P-22 resting on a rock outcrop, licking his paw to ear to muzzle, observing the snake of traffic below, hearing the hoot of the owl above. His ears twitch and he causally bats away a fly. He half-closes his eyes.

And together, we sigh.

Home. Home at last.

~Brenda Rees, FoGP boardmember

(The first image of P-22 was recorded on February 12, 2012 at 9:15pm; he was discovered during the Griffith Park Wildlife Connectivity Study, a project funded primarily by Friends of Griffith Park with additional support from the Hollywood United Neighborhood Council (HUNC). The study was overseen by Cooper Ecological Monitoring and conducted by biologists Dan Cooper and Miquel Ordeñana along with Erin Boydston of the USGS Western Ecological Research Center. The study featured several trail cameras placed strategically throughout the Park; the study ran from 2011 — 2014.

Photos: Courtesy Miguel Ordeñana

A recent article in The New Yorker magazine encapsulates the growing problems for mountain lions and other species isolated by Southern California freeways.

The last in the series on our Species of Special Concern highlighted the different species of bats found in and around Griffith Park, and Miguel is now expanding this study further into the Los Angeles community thanks to grants from various organizations.

Miguel began his discussion by noting that bats represent 20% of all mammals — imagine — flying mammals. There are over 1,400 bat species WORLDWIDE, helpful in a variety of ways as they distribute seeds and save agriculture to the tune of over 23 BILLION dollars, consuming pests targeting such products like corn! Unlike our perception, most bats are NOT blind, but in many cases do use echolocation to locate food and navigate in the dark. Echolocation is a high-pitched sound wave, as Miguel demonstrated, one that humans cannot hear.

For all unfamiliar with what constitutes a mammal: mammals are warm-blooded, provide milk for their young, maintain a constant body temperature, have a spinal cord connected via vertebrae, and are covered with “furry” hairs which provide insulation in cold climates. BTW, we humans also fit this bill.

Also, contrary to the preponderance of vampire films presenting a negative view of the humble bat — bats primarily eat insects, although there are some “vampire” bats that feast primarily on cattle (further down in South America).

Please enjoy!

The ZOOM recording can be accessed here.

More information on how bats save the farmer can be accessed here.

Miguel Ordeñana attended USC (undergrad) and UC Davis (masters degree in ecology). Prior to his current occupation at the Natural History Museum, Miguel worked with Dr. Dan Cooper (Cooper Ecological Monitoring, Inc.). It was Miguel Ordeñana who first documented the entry of P-22 into Griffith Park.