Discovering Bats in the Night Sky, October 1st

Article and Photos by FMN Laura Anderko

On October 1, 2023, FMN offered a hike to its members to learn about and view bats, with expert Deborah Hammerer. The group met at Dyke Marsh trail in Alexandria, VA to discover the many bats native to the area. Deb used a sonar detector to hear the bats echolocating as they hunt for insects. The group was not disappointed! We were treated to dozens of bats including Little brown bats and big brown bats. Adding to the suspense, a barred owl called out into the night while the bats were in flight, catching insects – these birds are hunters of bats….

Photo credit: FMN Laura Anderko, Bat Night 10/01/2023

Deborah offered insights and information about bats. Bats belong to a group of animals called Chiroptera (Kir-op-tera), which means “hand wing.” Bats are the only flying mammal. Using a bat puppet, she described how bats fly.  Deborah described a bat’s wing resembling a human hand — with a flexible skin membrane that extends between each long finger bone and many movable joints. This makes bats acrobatic in their flight, helping them catch insects. They also use echolocation – sending out waves of sound to locate insects during flight. Each night, bats can eat their body weight in insects, numbering in the thousands, reducing disease and helping farmers. Bats are important pollinators too – over 500 plant species rely on bats to pollinate their flowers including mango, banana, guava, and agave. Bats are incredible creatures!

The evening ended with a beautiful moonrise over the Potomac…

Photo credit: FMN Laura Anderko, Bat Night 10/01/2023

FMN Quarterly Chapter Meeting, Graduation, and Presentation by Award Winning Interpretive Manager and Naturalist Suzanne Holland: December 18 at 7:00 PM

Photo credit: Kim Young,  Southern Flying Squirrels (Glaucomys Volans)

Join us as Naturalist and award-winning Interpretive Manager Suzanne Holland presents on Southern Flying Squirrels (Glaucomys volans) – a native of Virginia. Flying squirrels are technically not fliers, but expert gliders, using the membrane between their ribs and ankles to glide. They can cover 150 feet in a single glide!  After the presentation, we will have an opportunity to observe flying squirrels from their feeding boxes.

Suzanne Holland has served Fairfax County residents for over 30 years and was honored by the County for her outstanding contributions when she retired in November 2022. Suzanne was among the first to broaden engagement to diverse communities and to train others about the importance of nature for children and families. She partnered with the Office for Children for over a decade of “teaching the teacher” programs, leading diverse county preschool teachers on methods of teaching about nature. In addition, as a member of the Mason District Task Force on Equity, Suzanne worked with Hidden Oaks Nature Center staff to create opportunities for equity programming for local Latino and Asian communities.

Suzanne Holland and Bob Dinse with Wildlife Tree Sculpture-Photo credit: Jerry Nissley

Among the many awards Suzanne earned over the 30 years at Hidden Oaks, she received the National Association for Interpretation (NAI) S.T.A.R.S. award for outstanding interpretive work, especially in her efforts to educate interpreters for the FCPA.  Other efforts include the creation of Nature Playce (a woodland play area near the Hidden Oaks Nature Center) and the development of monarch butterfly conservation stewardship programming.

Nature Playce (a woodland play area near the Hidden Oaks Nature Center)

Kim Young, FCPS Hidden Oaks’ senior interpreter, will join the presentation. Kim has led dozens of flying squirrel presentations for the Park Authority plus a program for the Friends of Dyke Marsh. She is a flying squirrel-whisperer and will share her recommendations of encouraging these charming creatures to visit your backyard feeding station and nesting boxes. We will be raffling off a flying squirrel feeding box after the presentation!

This event will include a potluck dinner: please feel free to bring a dish to share – appetizer, main dish, or dessert.

FMN members can record one CE hour under Continuing Education – FMN: Chapter Meeting Presentations.

Location: Hidden Oaks Nature Center, 7701 Royce Street, Annandale, VA 22003
Hidden Oaks Nature Center Location

Please note: The main parking lot is in Annandale Community Park at the Packard Center, 4022 Hummer Rd.
Upon entering the park from Hummer Road, take the right fork of the driveway and park in the back of the lot adjacent to the Packard Center. Look for the arch into the woods and follow the Storybook Trail to Hidden Oaks Nature Center. This walk is on an ADA- certified paved trail and is about 75 yards. Follow the adventures of woodland creatures as you weave through the woodland to the Nature Center.

More information about Hidden Oaks:

“Take Back the Forest” Twin Lakes Golf Course Invasives Management Area, November 5th

Photo Image: Courtesy of FMN Joe Gorney

Sunday, 5 November 2023
2:00-6:00 PM

Twin Lakes Golf Course
Invasives Management Area
6201 Union Mill Road
Clifton, Virginia

Site Leader Contact Information:
Joe Gorney
Cell/Text: 703-861-7322
[email protected]

FMN Members,

I’m the Site Leader for the Twin Lakes Golf Course Invasives Management Area in Centreville (just south of the Centreville High School). I have a workday planned for Sunday afternoon, November 5, staring at 2:00 PM. While I already have my full slate of 10 volunteers for that day (mostly students and their parents), I’m soliciting extra FMN volunteers to remove large vines and shrubs from a particularly overgrown area. I have reserved a large (30 yards) roll-off dumpster for the day, which will only be available for the weekend, and I would like to fill it.

The work would consist primarily of lopping or sawing off woody vegetation and dragging it about 75 yards to the dumpster. Our tools will be loppers and small tree saws. The principal targets include Autmn olive, Asiatic bittersweet, honeysuckle vine, and honeysuckle shrub. We might also dig out some of the roots with shovels.

If you are able to help on that day, please let me know via email. Although this event is already “full” on the on-line FCPA volunteer system (which is capped at ten volunteers), I could use at least another 10 people so that we can fill the dumpster! While I normally plan my volunteer workdays for two hours, I plan to keep cutting and dragging from 2:00-6:00 PM, to take full advantage of the dumpster. I will also reserve extra loppers, saws, shovels, tarps, and gloves from FCPA for the workday. I will report volunteer information and hours worked to FCPA after the event.

Please let me know if you can help “Take Back the Forest.” Thanks!

Tools and gloves will be supplied. Please bring water, insect repellant, and sunscreen. Wear long sleeves, long pants, hats, and sturdy shoes.

Enter the golf course from the main entry off of Union Mill Road, just south of Centreville High School. Once you enter through the gates, drive about 0.4 miles to the northern clubhouse parking lot and turn left into the lot. Park along the northern edge of the parking lot, closest to Work Area 1.

Work Areas:
Work areas are the north of the northern parking lot. Most student volunteers will continue to focus on Area 1. FMN volunteers will focus on the mature invasives within Area 2.

Joe Gorney

TWIN Lakes IMA Site Leader
[email protected]

Despite Predation, Bluebirds at Langley Fork Park Endure

Tree Swallow Residents of Box 11 (June 22, 2023).  The tree swallows would generally survive better than their bluebird competitors at Langley Fork Park in 2023.

Article and photos by FMN Stephen Tzikas

As Bluebird Trail Monitoring Leader at Langley Fork Park in McLean, I have been trying to optimize the environment for the bluebirds at the park. The trail monitoring team and former trail leader all help in the effort, so I am fortunate to have their assistance.  

In 2021 we nurtured 63 total protected birds which included 26 bluebirds.  In 2022 we had 57 total protected birds which included 24 bluebirds.  In 2023 we had 49 protected birds of which 14 were bluebirds.  This can be contrasted to the five years prior to that in which Langley Fork Park monitoring succeeded with about 40 protected birds per year which included about five bluebirds a year.  Our efforts in the recent past are successful compared to the longer historical record. 

Were it not for the loss of 14 bluebird eggs in 2023, the count could have been 28 bluebird fledglings.  That would have been larger than the 2021/2022 counts.  All but one of the bluebird eggs were loss to predation.  On the other hand, all but one of the seven unhatched tree swallow eggs were part of clutch sizes that also included fledglings.  The solitary tree swallow egg in a Box 11 attempt was overcome by an ant infestation.  Another year of snakes at Box 7 resulted in five tree swallow nestlings being devoured. Consequently Box 7 has been moved, as was Box 9, that had four bluebird eggs vanish.  Indeed Box 7 was also attacked by a snake last year.  There aren’t any overhead trees in the area, and we maintained the grass so no large weeds could provide a pathway for snakes.  Nonetheless, it seems snakes can be skillful predators traveling up the bluebird pole and baffle.

As for a solution at the end of the season, we paired Box 7 with Box 4, as pairing boxes can provide

Box Pairing Experiment at Langley Fork Park. Boxes 5 and 9 in the photograph are spaced approximately 10 feet apart, as are Boxes 4 and 7.

positive outcomes when good park locations for boxes spaced more than 100 yards apart are limited.  This solution was used for Box 9 too, as it seems the birds didn’t care for all the playing field activity around Box 9’s former location.  Box 9 is now paired with Box 5.  This will be an interesting experiment. 

Bluebirds are territorial, so two pairs generally won’t nest in boxes that are closer than 100 yards. Though, boxes in pairs might attract a different species, like tree swallows.  Tree swallows compete with other species such as bluebirds, as well as their own species.  Tree swallow pairs will compete, sometimes to their deaths, with each other for nest sites.  Male tree swallows will claim a bird box and guard it, in hopes of attracting a female tree swallow.  Consequently there is a strange dynamic ensuing.  By installing boxes in pairs, they will be close enough that both boxes are unlikely to be occupied by the same species, but just plentiful enough to allow for another species without an aggressive competition between the two species.  This strategy has worked on bluebird trails.  There are different recommendations on how far apart to place the pairs, from on the same pole to as much as 24 feet apart. We placed our two pairs at about 10 feet.

Status of 2022 Changes

The start of the 2023 monitoring season incorporated some changes recommended in 2022.  Our team agreed that moving Boxes 1, 4, 7, 9 might help the bluebirds.  The data showed that Boxes 1, 2, 5, and 9 never had bluebirds. We also had the opportunity to add an 11th bluebird box which was installed.   

  • Box 1 was moved closer to the parking lot to get more attention by the bluebirds.  As a result of the move, the box produced 3 bluebird and 5 tree swallow fledglings. 
  • Box 4 has had occasions of broken eggs from intense competition.  Moving it from the corner of the field to a more bushy area closer to some benches improved it.  In 2023 this box produced 5 tree swallow fledglings.
  • Box 7 had a snake predator in 2022, but it was not under any trees and the weeds around it were cut.  We decided to leave it in place at the last moment in 2022.  Unfortunately in 2023 it was once again attacked by snakes.  No fledglings survived.  To avoid that mistake again, Box 7 is now paired in a good location for the upcoming 2024 season. 
  • Box 9 was moved a few yards farther from the human activity at this playing field area. Yet in in 2023 this box did not produce any fledglings and four bluebird eggs went missing. It is now paired in a better location for the upcoming 2024 season. 

Finally, something should be said of unhatched eggs, which for the most part is uncontrollable. Unhatched eggs could be a result of issues related to temperature, humidity, infertility, environmental chemical use, or physical damage to the eggshells. Sometimes too, if the female bird is inexperienced, or if there is not enough food nearby and she has to leave the nest frequently to forage, the eggs can be affected  negatively.

Author Talk: “What an Owl Knows” with Jennifer Ackerman, October 19th

Image: Courtesy of the Audubon Society of Northern Virginia

Thursday, October 19, 2023
7:00 PM – 8:00 PM
Virtual, hosted by Audubon Society of Northern Virginia

Fee: Members $25 (Non-members$350

Register here.

For millennia, owls have captivated and intrigued us. With their forward gaze and quiet flight, owls are often a symbol of wisdom, knowledge, and foresight. But what does an owl really know? And what do we really know about owls? Though our fascination goes back centuries, scientists only have recently begun to understand in detail the complex nature of these extraordinary birds.

Join Jennifer Ackerman, author of The Genius of Birds, for an author talk about her latest book, in which she illuminates the rich biology and natural history of owls and reveals remarkable new scientific discoveries about their brains and behavior. What an Owl Knows is a fascinating exploration of owls across the globe and through human history, including an account of their astonishing hunting skills, communication, and sensory prowess.

Jennifer Ackerman has been writing about science and nature for almost three decades. Her New York Times bestseller, The Genius of Birds, has been translated into 25 languages and was named one of the best nonfiction books of 2016 by The Wall Street Journal, a Best Science Book by National Public Radio’s “Science Friday”, and a Nature Book of the Year by the London Sunday Times. Her other books include Birds by the Shore: Observing the Natural Life of the Atlantic Coast (2019 reissue by Penguin Press of her first book, Notes from the Shore), Sex Sleep Eat Drink Dream: A Day in the Life of Your Body, and Chance in the House of Fate: A Natural History of Heredity. Ackerman’s articles and essays have appeared in National Geographic, The New York Times Magazine, Scientific American, and many other publications. She is the recipient of numerous awards and fellowships, including a National Endowment for the Arts Literature Fellowship in Nonfiction, a Bunting Fellowship, and a grant from the Alfred P. Sloan Foundation.

Invasive Removal and Habitat Restoration, October and November Dates

Photo: Earth Sangha, Section of restored native woods at the preserve.

Join these efforts to remove invasive species, repair trails, and otherwise beautify natural spaces!

Stream Monitoring Citizen Science & Training Opportunities, October and November Dates

Photo by FMN J. Quinn, Stream monitoring at Pohick Creek.


Little Difficult Run Stream Monitoring Field Training

When: Saturday, October 21, 2023
Where: Fred Crabtree Park, Herndon

This beautiful stream site is located a short hike into the woods and has a large diversity of macroinvertebrates. A visit to this site is highly recommended for anyone looking to practice their macroinvertebrate identification skills, for their VASOS certification or for fun! Learn more and register for this workshop and others here.

Sugarland Run Stream Monitoring Workshop

When: Monday, November 6, 2023
Where: Sugarland Run Stream Valley Park, Herndon

This site is lovely in the fall, and we usually find some fun hellgrammites and crayfish. This site is also close to one of the largest great blue heron breeding and nesting grounds in the region, and we may see some visitors from their northern range in the area. Pretty neat! Learn more and register for this workshop and others here.


Pohick Stream Monitoring Field Training

When: Wednesday, November 8, 2023
Where: Pohick Creek Stream Valley Park, Springfield

This site has a greater flow and wider stream than any of our other sites. Does more water mean more macros? Only one way to find out… Learn more and register for this workshop and others here.

Big Rocky Run Stream Monitoring Workshop

When: Saturday, November 11, 2023
Where: Cabell’s Mill, Ellanor C. Lawrence Park, Chantilly

Join us for our last stream monitoring of the fall season! Volunteers at this site often visit and enjoy the park’s nature center and interpretive trails. Learn more and register for this workshop and others here.

More Training and Stream Monitoring Opportunities

The NoVa Soil & Water Conservation teams are  very excited to contribute their stream data to state and national datasets. If you’d like to see data from all the NVSWCD regional stream monitoring team’s active sites, you can find our organization on the Clean Water Hub.

The “Birdman” Behind the Migratory Bird Treaty Act with Will McLean Greely, November 2nd

Image courtesy of Will McLean Greely

Thursday, November 2, 2023
7:00 PM – 8:00 PM

Virtual Meeting

Registration is required.

Fee: ASNV Members, $10; ASNV Non-members, $15

Join the Audubon Society of Northern Virginia (ASNV) for an author event and learn about the man behind the ground-breaking, 1918 Migratory Bird Treaty Act. It’s one of the country’s first and most important conservation laws and has saved billions of birds.

Will McLean Greeley will provide an overview of his new biography, A Connecticut Yankee Goes to Washington: Senator George P. McLean, Birdman of the Senate. This is the story of how Connecticut’s George P. McLean helped establish lasting legal protections for birds that is still in effect today. Greeley, McLean’s great-great-nephew, puts McLean’s victory for birds in the context of his distinguished forty-five-year career marked by many acts of reform during a time of widespread corruption and political instability.

Will McLean Greeley grew up in western Michigan with a passion for American history, politics, and birds. He earned a bachelor’s degree in political science from the University of Michigan, followed by a master’s degree in archives administration. After retiring from a thirty-five-year career in government and corporate market research, he embarked on a three-year journey of research and writing to produce the story of his great-great-uncle George P. McLean and his legacy. Greeley, married and the father of two sons, and twice a grandfather, lives in Midland, Michigan. A Connecticut Yankee Goes to Washington is his first book.