Letter to Our Members: Right Now Is a Great Time to Get Rid of Your Invasive Plants

Photo: Callery pears, Tom Blackburn

Tom Blackburn, Chair, Advocacy

The Virginia Legislature has passed legislation, now awaiting the Governor’s signature, which will help combat the spread of invasive plants. You can read more about that here. But the new laws don’t do anything about the invasive plants in your own, or your neighbors’, yards. Here are a few that are at the top of my Enemies List, along with some suggestions on what to replace them with. 

Callery (Bradford) Pear: As I drove south on I-95 the other day, I was struck, as I am every spring, by the thousands of Callery Pear trees along the highway. For most of the year, Callery Pears are not very noticeable. But they burst into bloom in early spring, reminding everyone of how invasive they are. Do you still have one in your yard? We had two, bought when they were still considered to be the perfect ornamental tree. They lasted until my wife Brenda, and I decided twenty-five years ago that they had to go. My wife, more action-oriented than I am, began cutting one down with a hand saw about 5:30 one Sunday morning. She woke me up to tell me the 30-foot-tall tree was about to come down. I threw on some clothes and rushed outside in time to see the tree topple over into the street, narrowly missing our dog. We spent the next three hours cutting it up to make the street passable for people heading to church. 

Do you still have a Callery Pear in your yard? I don’t necessarily recommend removing it the way we did, but here are a few reasons to get rid of them: 

• The blossoms smell bad – like rotting fish or dirty laundry. They smell bad because they attract flies, their principal pollinators. Do you like stink and flies?

• The fruits are laced with cyanide. Do you want a poison tree on your property?

• The trees readily lose limbs because of their weak structure. Don’t park your car under one during a windstorm!

• And here’s the most important reason: They are highly invasive, forming extensive stands, often along roadways, where they crowd out all other species. 

When you take down your Callery Pear, here are some great native alternatives to plant in its place. 

Nandina: Nandina (Heavenly Bamboo) was promoted as a perfect ornamental plant because it is evergreen, deer-resistant, and has beautiful red berries that last into winter. We also used to have Nandina in our yard until we learned the hard way how invasive they can be. Nandina is still being sold despite widespread recognition of its danger to the environment. My sister bought a house in a new HOA development three years ago and found that the developer had planted both Nandina and Bradford Pears in the front yard of every single house! Do you still like your Nandina? Here are reasons to get rid of it now:

• Its berries contain cyanide and are poisonous to cats, dogs, and children. Do you really want to have poison berries that look good enough to eat in your yard?

• They are particularly poisonous to birds, and there are reports of small flocks of Cedar Waxwings eating the berries and dying by the dozens within a few minutes of eating them.

• They spread from rhizomes, meaning that they won’t stay where you plant them, and they are hard to get rid of.

• In the wild, they spread rapidly, forming dense stands that crowd out other plants.

If you like the way Nandina looks, but don’t want to keep an invasive poisonous plant, you can find good alternatives that don’t harm the environment. The NVBA website has two great articles on Nandina substitutes by Julie Udani and Alyssa Morel.

Japanese Barberry: We never planted Japanese Barberry, realizing that sharp thorns and active children didn’t go well together. But many people like it because it can create a dense hedge and has attractive foliage. Here are reasons to get rid of it now:

• The tips of the spines are finer than a hypodermic needle and can easily break off under the skin. The tips contain silicate that doesn’t decompose readily, causing painful and lasting skin irritation. Use thick gloves if you are pruning or removing Barberry by hand. 

• The plant spreads rapidly because it produces numerous berries and seeds and also re-roots wherever the drooping branches touch the ground. In the wild, it quickly creates dense, impenetrable thickets. 

• The plant alters soil pH, making it inhospitable to other plants. 

Here are some great alternatives to Japanese Barberry.

More invasives: My Enemies List of invasive plants doesn’t stop at three. With more space, I could go on about the hundreds of English ivy seedlings that show up in our yard from seeds spread by birds from neighboring yards; the hundreds of White Mulberry seedlings that spring up in our vegetable garden from seeds dropped by birds from a neighbor’s tree; the Italian Arum that we once planted and took almost 10 years to eradicate; and more. The worst of the invasive plants are on the Virginia Invasive Plant Species List, but other invasive species haven’t made the list. There’s no substitute for careful research if you want to avoid making a mistake with both personal and environmental implications. 

Thompson Wildlife Management Area in Spring

Photo: Trilliums and Mayapples in bloom, Sudhir Viswarajan, CC BY-SA 4.0, via Wikimedia Commons

Usha Hippenstiel

During the transition from winter to spring, nature shows off. There are a trillion different emerging sights, but few as captivating as the trilliums (Trilliaceae family). Boasting one of the largest concentrations of trillium in Virginia, the G. Richard Thompson Wildlife Management Area (often abbreviated to Thompson WMA) stands out as a spring destination. Managed by the Virginia Department of Wildlife Resources (DWR), the Thompson WMA is located along the eastern Blue Ridge Mountains in northwest Fauquier County, with parcels in Warren and Clarke Counties. The 4,000-acre area boasts hardwood trees, remnants of fruit trees, streams, semi-open vegetated slopes, and its famous spring ephemeral blooms. 

Although the Thompson WMA is worth a trip any time of year, spring is the time to see the display of ephemerals. Beginning in late April through mid-May, the forest floor is covered by blooms. A particular two-square-mile area within the Thompson WMA hosts an extensive covering of the white trillium (Trillium Grandiflorum) and is reputed to be the largest plant community of its kind in Virginia - with some arguing it might even be the largest in the United States. The DWR website provides guidance for viewing the spring wildflower display.

It’s worth remembering that at one point the habitat was at risk of being fragmented and lost. In 1990, the DWR (then known as the Virginia Department of Game and Inland Fisheries) proposed a project to log the forest in the Thompson WMA. The project called for heavy machinery and large-wheeled logging trucks that would cross through areas where the trillium population grew. 

Fortunately, the Virginia Native Plant Society (VNPS) and other concerned citizens rushed into action to designate the area as the first site on the Virginia Native Plant Registry. The registry is a voluntary program designed by the VNPS to protect the native plant resources throughout Virginia. Recognition of the designation by DWR allowed the agency to manage the area to protect the spring ephemerals. 

If you're planning a trip this spring, aim for around the first week of May for optimal viewing. Pay some attention to general warm or cold fronts toward the end of April because they can affect the timing. Warm springs push trillium blooming earlier and cold springs push blooming later.

While there, keep your eyes and ears out for the area’s warblers and other iconic birds of the area. Watch for flashes of yellow and you might be lucky to spot a Hooded Warbler, a Worm-eating Warbler, or the Kentucky Warbler, all of which are seen in this area more frequently than the regional average. Although not common, you could also see a Blackburnian Warbler. Other Trillium Trail favorites eBird lists as iconic include the lovely Cerulean Warbler and Scarlet Tanager, but any springtime visit will provide views of many of the 135 species eBird lists for that hotspot. 

Consider taking a trip to the Thompson WMA this spring if you desire a lovely day surrounded by wildflowers and other emerging sights and sounds of spring!

Usha Hippenstiel is a young, passionate, DC-based environmentalist working in the natural resource sector.

Spring in Virginia: Some Birders’ Thoughts

Photo: Blue-winged Teal, Joyce Palm/Audubon Photography Awards

Summer Delehanty

On a particularly overcast and chilly day in March, it’s hard to believe the next few months bring warmth, greenery, and a slew of migratory birds. Yet spring marks the beginning of another migration season in Virginia, with hundreds of thousands of birds making their way back from a tropical winter to their summer breeding grounds in North America. After snow flurries and a couple of cold snaps this past month, here are a couple things local birders are looking forward to in April.

Passing Migrants

Warblers, vibrant and active little birds that pass through every spring, are often a fan favorite, especially when they congregate in colorful mixed-species flocks. Many species, no bigger than the palm of your hand, pass through northern Virginia in droves, often making pit stops on the way to their breeding grounds in Canada and the northern United States. While some species stick around for the summer, many can only be found here for a few weeks of the year.

The Blue Ridge Mountains are a popular spot to look for warblers, but these birds can also be found in many local parks and even backyards, exhausted from their long-distance journey and seeking a place to rest and regain strength. One northern Virginia birder I spoke with is particularly excited for them to return to his yard. “We live in northern Virginia in otherwise boring suburbs, so the first time we saw a Palm Warbler in our backyard was a treat,” he said. Now, his backyard reliably attracts several species in the spring, including his lifer Cape May Warbler. “I just had to know what to listen for, which drove me to look more closely and spot them. There's so much variety!” He added.

Another birdwatcher, Christian McGuirk, described his favorite local warbler spot, Monticello Park in Alexandria. “It’s a small, nondescript park in Alexandria that is jam-packed with warblers and other migrants April [through] May. They come down from the high canopy to bathe in the stream that runs through the park. I don’t know what it is about that park they love so much, but I’m glad it’s there!” He added, “I’m looking forward to introducing some of my young cousins to birdwatching there and taking lots of photographs, hopefully with some lifers in the mix.” 

Spring is also a great time for passing shorebirds. Another local birdwatcher said, “In a couple of weeks, the Blue-winged Teals will be making pit stops around here, ushering in shorebird season!” Like warblers, these birds are returning to their summer breeding grounds, using Virginia as a stop along the way. Birders may spot some of the earliest migrants, like Greater Yellowlegs, when they pass through in late April, followed soon after by the rest of their shorebird friends. 

Returning Summer Residents

Prothonotary Warbler. Photo: Donald Wuori/Audubon Photography Awards

In addition to birds just passing through, keep an eye out for returning breeding residents, or birds that spend their springs and summers in northern Virginia. While these birds also migrate, Virginia is far enough north for them to stay, rather than continuing to New England or Canada. Some notable returners include Baltimore Orioles, Scarlet Tanagers, and Prothonotary Warblers, sporting fiery shades of red, orange, and yellow.

As the trees regain their foliage, many of the birds are easier heard than seen. Spring is when many birds start singing again, whether to establish territory or attract a mate, so prepare for an explosion of new voices this April. One birder commented on the joy of hearing familiar songbirds again: “It is the sounds I am most anticipating—Great-crested Flycatchers, Indigo Buntings, orioles, and pewees calling.” The birds’ musical songs can be heard in parks all across northern Virginia beginning in late April and early May, after a long hiatus through the winter months. “It is like old friends coming back from a long break,” he added.

Baltimore Oriole. Photo: Adrian Azar/Audubon Photography Awards

Birding with Friends

Finally, on the subject of friends, warmer weather often means more people will be spending time outdoors. Birding in the winter requires lots of layers, lots of patience, and a special kind of dedication. Spring brings more comfortable conditions and a wider variety of birds to find, drawing many birdwatchers back into the field. Rachel Barham, a classically-trained singer working in DC and an accomplished birder by ear, is most excited to see familiar faces again. “I can’t believe I’m hearing my introvert self say this, but I am really looking forward to connecting with our amazing birding community in person!” Barham said. “I don’t see everybody as much in the winter, and birding together is so joyful, even on slow days.” 

In the midst of pollen attacks and crushing cherry blossom crowds, it’s easy to overlook the smaller signs of spring. Whether chasing lifers, spending time with other birdwatchers, or simply enjoying the influx of returning singers birds, birders can’t wait to get outside and embrace the new season. 

Summer Delehanty is a product designer with a passion for birdwatching.

Why I Keep Coming Back: Birding and Photography Along Marumsco Creek

Photo: Great Blue Heron, Kent Blumberg

Kent Blumberg

My favorite birding spot is Veterans Memorial Park in Woodbridge. It’s close to my home and offers a variety of habitats: Marumsco Creek along the western edge of Occoquan Bay National Wildlife Refuge, cattail marsh, Osprey nests on light poles, and a small strip of forest that often hosts migrant songbirds. 

I keep coming back for the surprises that appear around every bend in the trail. 

There are several easy places to park, depending on how far you want to walk. A gravel lot sits at the corner of Featherstone Road and Bay Street, perfect if you want a longer walk along the soccer fields before heading to the creek. For a shorter visit, park near the skateboard park or at the baseball fields at the end of the road.

The trail along the creek is flat and well-maintained, making it accessible for most visitors. There’s one short section with steps near the recreation center, but otherwise it’s an easy walk.

The trail follows the creek for about a half mile. I usually walk out and back the same way. It’s always surprising how much the scenery and birds change when I turn around.

The edges of the soccer fields can be surprisingly productive. I’ve spotted migrating warblers, Ospreys feeding, and Red-bellied Woodpeckers in mid-molt, along with other surprises.

Over the years, eBird reports include more than 200 species here. Highlights of my visits include Great Blue Herons, Brown Creepers, Eastern Bluebirds, Ospreys, Wood Ducks, and many others. If you’re looking for specific species, pay attention to the tides. Low tide exposes mudflats that attract shorebirds, while high tide brings in more waterfowl.

Osprey with breakfast. Photo: Kent Blumberg.

As a photographer, I’m always looking for interesting bird behavior. One morning I spent 30 minutes watching a Great Blue Heron wrestle with a huge catfish, repositioning it again and again before finally swallowing it headfirst. On another visit, I came across an Osprey enjoying breakfast in a tree next to the soccer fields. Moments like these are why I keep coming back.

The trail runs along the west side of the creek, so morning light can be tricky. I’ve had the best luck standing in the shade of a tree and shooting north or south for better side lighting.

During warmer months, the pickleball courts near the recreation center can get noisy. If you prefer a quieter experience, visit early in the morning or on a weekday.

Restrooms are available at the recreation center and baseball fields during warmer months, along with several portable toilets. Both are typically closed in winter.

If you’re looking for a peaceful place with a surprising variety of birds, consider a visit to Veterans Memorial Park. You never know what might be waiting just around the next bend. 

Kent Blumberg is an MBA professor, passionate bird photographer and voracious reader. 

It's Time for Birdathon!

As spring arrives in northern Virginia, we’re looking forward to Birdathon 2026, our annual event where teams collect pledges from friends and family and then record how many species they can identify during any 24-hour period between April 18 and May 19. In addition to being just plain fun, Birdathon helps NVBA to support outdoor education, citizen science, habitat conservation, and programs to encourage people to plant native plants and protect native wildlife. Birdathon also helps ornithologists better understand spring migration by reporting sightings through eBird, an online database of bird observations run by the Cornell Lab of Ornithology.

More information is available on our Birdathon 2026 webpage. You can plan a big day route around northern Virginia, or you can even participate from your own backyard. So, gather your birding buddies and register your team today.

Team captains, and anyone curious about joining a birdathon team, are welcome to join us on April 13th for our captain kick off event, and we we will have NVBA sponsored birdathon days as well - information coming soon. 

The Birds Are Coming! It’s Time to Turn Off Your Lights at Night

Photo: Purple Martins, Keith Kingdon/Audubon Photography Awards

Over 100 million birds will migrate through northern Virginia in the next two months. Tundra Swans, Dark-eyed Juncos, and other winter visitors have departed for their breeding grounds, while warblers, tanagers, phoebes, flycatchers, and other species are making their way from Central and South America to or through our area.

Eighty percent of our migrating birds migrate at night. They use a variety of cues to keep themselves on track, including the stars, Earth’s magnetic field, geographic landmarks, and genetics. However, excessive lights at night can be deadly for them. Some birds crash into lighted buildings at night, injuring or killing themselves. The worst recent example is the McCormack Place Convention Center, where over 1,000 birds died in one night, but smaller numbers of birds die from window collisions at night throughout the country. Other birds are distracted from their migration routes by lighted buildings and fly around the lights much like moths attracted to a light. They waste the precious energy they need to get to their breeding grounds, increasing the likelihood that they will never reach them.

You can do your part to help keep migrating birds safe by turning out your outdoor lights between 11:00 PM and 6:00 AM from now through the end of May. You also can install motion sensors on your lights, so they come on only when they are needed. 

You can also help birds by minimizing outdoor lights throughout the year. Scientific studies are making it increasingly clear that lights at night disturb birds’ sleep, causing them to lose weight, lay fewer eggs and have fewer baby birds that survive to leave the nest. 

Would you like to learn more about the effect of outdoor lights on birds? Join us for an online program about the importance of reducing outdoor lighting. Our speakers will be Joelle Gehring, the Acting Assistant Regional Director for the U.S. Fish and Wildlife Service’s Migratory Bird Program, and Jo Anna Lutmerding, a Biologist in the U.S. Fish & Wildlife Service’s Migratory Bird Program. Joelle and Joanne are the co-leaders of the Bird Collision Prevention Alliance, a coalition of over 100 organizations (including NVBA) who are committed to making our built environment safer for birds. You can register for this free program here.

Judging a Plant by its Label

Photo: Native plants at a garden center, Margaret Fisher

Eileen Ellsworth

Are you hunting for a particular native plant, shrub, or tree? Any native plant seller near you is a terrific place to shop. A list of native plant sellers can be found on the Plant NOVA Natives website. Browsing a commercial garden center is also an option, so long as you understand how to read plant labels.

Finding natives in commercial garden centers can be challenging. Plant labels, excepting those that Plant NOVA Native volunteers have already tagged in red as “Native,” rarely offer much information and use terms that can be confusing. Here are some definitions and tips to help you find exactly what the biodiversity of the region needs.

Plant label definitions: 

It’s helpful to group plant label terms into two groups: those pertaining to nature-made and those pertaining to human-made plants.

Nature-Made:

• A straight species is a 100% nature-made group of similar plants that can interbreed and reproduce by seed.

• A natural hybrid occurs in nature without human intervention between two native species.

• A variety or form arises within one native species as a genetic mutation and causes certain distinctive traits to appear.

Human-made:

• A cultivar is a strain of a specific, individual plant that growers produce in bulk for its desired commercial quality. These are usually (though not always) propagated from cuttings, which means that they are clones of each other. The name of the cultivar will be in single quotes, such as Rudbeckia fulgida ‘Goldsturm.’

• A human-made hybrid or hybrid grouping is an individual plant or class of plants created by growers by crossing one species with another. They arise from similar yet complex breeding lines that all share a “hybrid” status. The scientific name on the label will include an “x” to designate hybrid status. It can be quite difficult to determine the exact lineage.

Buying tips:

Given the above terms, here are some tips on understanding plant labels before buying. 

• If the label provides the scientific name of a locally native species, including the genus and species, such as Monarda didyma, then this is the best choice for the local ecosystem. You can double check if a species is locally native by referencing the free Virginia Botanical Associates' Digital Atlas of Virginia Flora, which will not only advise if the plant is native to Virginia, but to northern Virginia as well. It could be the straight species, which is the most beneficial of all, or it could be a cultivar. If it is a cultivar, then it is a particular individual plant that the grower has cultivated in bulk by cloning for commercial sale. They are chosen for traits like size, color, resistance to mildew, etc. Cultivars differ from the straight native species. If the difference is only size, the cultivar will probably support wildlife well. But if the cultivar has altered the structure or color of flowers, native bees can’t access their nectar or perhaps recognize them as a source of food and shelter. Sometimes a cultivar changes the leaf color to red or purple, which also alters the plant’s chemistry. This can make them unsuitable as larval hosts for the butterflies, moths, and other insects that evolved to depend upon them. It’s best to use cultivars in locations distant from natural areas and only choose those that have not altered the straight native’s flower structure or color, fruit size, or leaf color.

• If the label provides the name of a hybrid (with an X), then it is a cross between species, and the human-made version is not native, meaning you’re risking the introduction of a non-native species into the region. As you can see from the plant label definitions above, hybrids can arise in nature or be man-made. But commercial garden centers sell human-made hybrids because their growers want controlled uniformity and protection for their intellectual property. These plants must be cloned as they do not produce seeds, and only plants grown from seeds create genetic diversity and improve species’ resistance to climate change and other environmental stressors. Human-made hybrids will not improve the biodiversity of your property.

• If the label provides only a brand name, then research would be needed online to figure out what it really is. It could be a cultivar or a hybrid.

The Plant NOVA Natives website has more information about plant label terms and buying tips. And you can always download our excellent Guide to Northern Virginia’s native plants to refine your shopping list of beautiful, straight-native plants.

A Closer Look: Nature All Around Us, April 2026

Photo:  Palm Warbler with Katydid, Judy Gallagher

Judy Gallagher

April 2026

 Common True Katydid, looking like a leaf. Photo: Judy Gallagher

I hear katydids more often than I see them. One reason for this is that many species are nocturnal, but many species are so well camouflaged that one doesn't always see them even when they are very close. 

Katydids are named for the call of the Common True Katydid, whose males call "Ka-ty-did" when searching for a mate. But each species has its own song, and the songs are used for reproductive, territorial, aggressive, or defensive reasons. The males are usually the singers, but some females also produce sounds. The songs are produced by friction on special structures on the front wings. A few species pound on twigs, which produces vibrations that can be detected by other katydids. 

Katydids are in the order Orthoptera, which also contains grasshoppers and crickets. Katydids hold their wings vertically over their body, have hearing organs on their legs, and have very long thin antennae that are often as long as their body. The antennae contain sensory receptors that facilitate them finding their way after dark.

There are around 6,400 species found worldwide, most of which are in the tropics, and approximately 270 species in the United States. 

Handsome Meadow Katydid. Photo: Judy Gallagher

As I mentioned previously, most katydids are well camouflaged, but the Handsome Meadow Katydid is resplendent in a rainbow of colors. It shows up well against a gravel background, but it blends in surprisingly well in vegetation. Its genus is Orchelimum, from the Greek "meadow dancer," which aptly describes the way it moves around wet meadows. 

Spiny-devil Katydid, protected by sharp spines. Photo: Judy Gallagher

The spiny-devil katydids, found in Central and South America, easily blend into their environment, but they also have spines on their bodies, making it difficult for a predator to catch and eat them. When threatened, they can produce loud hissing sounds by rubbing their wings together, and they have strong mouthparts that can deliver a painful bite. 

Sooty Long-winged Katydid with insect prey. Photo: Judy Gallagher

Some katydid species are omnivorous, eating whatever they can, and a few species are ferocious predators, but most katydids eat plants. Their populations are typically low enough that they don't cause extensive damage to plants, so they aren't usually categorized as plant pests. 

Female Shieldback Katydid with long ovipositor and nuptial gift (the jelly-like blob). Photo: Judy Gallagher

Female katydids tend to be larger than males, and they have a long ovipositor at the end of their abdomen suitable for laying eggs in plant stems or in the ground. When katydids mate, the males will sometimes provide a "nuptial gift," a sperm packet with additional protein that will help the female develop her eggs. Females prefer males that give such a gift, but it costs the male up to 40 percent of its body weight to provide it. Still, that could be worth it if it allows the male to have a greater chance of having offspring. 

In our area, most katydids overwinter as eggs, which hatch in the spring. Katydids undergo incomplete metamorphosis, so the nymphs look pretty similar to the adults except they don't have wings. Nymphs typically molt five times before becoming a winged adult. 

Katydid Wasp with prey (a cricket). Photo: Judy Gallagher

Katydids have a number of predators, including other insects. A thread-waisted wasp called the Katydid Wasp specializes in capturing katydids and crickets, paralyzing them and taking them to underground burrows to feed their young. 

Palm Warbler with Katydid . Photo: Judy Gallagher

Bats prey on katydids, locating them by hearing their calls. Katydids also are a great food source for birds, including owls, bluebirds, kestrels and this Palm Warbler. 

I'm looking forward to hearing and seeing Katydids soon. I hope you also see and hear them. 

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View more of Judy’s articles on A Closer Look: Nature All Around Us (formerly Observations from Meadowood).

Wildlife Sanctuary Almanac: Plant a Butterfly Nursery in the Shade

Photo: Canadian Serviceberry, USFWS/Southeast, Public domain, via Wikimedia Commons

Julie Udani

Once there was a client who hired a landscape designer to create a pollinator garden for her. It looked beautiful and she was very happy to see butterflies flitting around throughout the summer and fall. The next spring, though, she called the designer very upset. “Caterpillars have infested all my flowers,” she said, “I had to have them sprayed.” True story.

Canadian Serviceberry, a host plant for Summer Azure butterfly larvae. Photo: USFWS/Southeast, Public domain, via Wikimedia Commons

Summer Azure butterfly caterpillar. Photo: Jacy Lucier, CC BY-SA 4.0, via Wikimedia Commons

Everybody loves butterflies, but caterpillars can be less charismatic. However, without caterpillars, we don’t have butterflies. Caterpillars are important to birds, too. Baby birds don’t eat seeds and berries. Overwhelmingly, bird parents rely on caterpillars to feed their young. According to Doug Tallamy, a brood of nestling chickadees needs between 6,000 and 9,000 caterpillars to reach adulthood.

Summer Azure butterfly. Photo: xpda, CC BY-SA 4.0, via Wikimedia Commons

This is good news for those of us with shady yards who want to support pollinators. Instead of focusing on typical pollinator gardens, full of nectar-bearing flowers that need full sun, we can plant a butterfly nursery. Most butterflies can only lay their eggs on a small group of plants. Monarchs famously prefer milkweed, but other species of Lepidoptera prefer other species of plants. And many of these can grow in the shade.

Just a few examples include dogwood and serviceberry trees that host, respectively, the Summer Azure and Viceroy butterflies. Shrubs that are larval hosts include the spicebush (Spicebush Swallowtail), the mountain laurel (Brown Elfin), and the black chokeberry (Coral Hairstreak). And shade perennials can bloom in all seasons to make a gorgeous butterfly nursery garden. Spring bloomers include violets (Aphrodite Fritillary, Great Spangled Fritillary, Meadow Fritillary) and golden alexander (Black Swallowtail). Summer perennials include white turtlehead (Baltimore Checkerspot) and black cohosh (Appalachian Azure). Fall features white woods aster (Silvery Checkerspot) and blue woods aster (Pearl Crescent). Even most of the sedges are larval hosts. 

Don’t leave the butterfly gardens to your neighbors. Welcome them into your shady yard - and the caterpillars, too!

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Catch up on past Wildlife Sanctuary Almanac articles here.

Letter to Our Members: Handling the Cold

Photo: Tufted Titmouse, Catherine McEntee/Audubon Photography Awards

Libby Lyons, President

I expect that many of you have wondered during the past frigid, snowy, and icy weeks, “How can birds survive the winter here?” That question has had me thinking too, and the answer seems to boil down (pun intended, see below) to two types of responses, i.e., behavioral and physiological, or a combination of the two.

Birds have several challenges to overcome in winters like this one. One is staying sufficiently warm. Some of the common adaptive bird behaviors I’ve seen include birds basking on the sunny side of a lake or river or hunkering down out of the wind in a dense evergreen tree. A visit to my brother in Port Angeles, WA one February suggested another type of beneficial behavior. Early one morning, with ice covering the bushes, I was gobsmacked to see an Anna’s Hummingbird flitting about. My brother said that he knew of one that had found a nice warm spot under the eaves of a house near his.

That hummingbird also may have benefitted from going into torpor, a physiological mechanism that’s akin to a short-term hibernation! This type of daily night-time torpor results in a lower body temperature and a lower metabolic rate. In this physiological state such birds, which usually require high levels of energy for their metabolism and flight, can conserve energy and survive very cold temperatures.

What are other physiological mechanisms birds use to stay warm? When we might go out and buy a down coat, many birds grow extra down feathers before the winter! The downy feathers are short and fluffy and lie below the larger outer feathers. These feathers trap air near their bodies where the warm air pockets act like insulation, shielding them from very cold temperatures outside. Birds often combine such feather growth with a behavior where they use muscles to fluff up their feathers, boosting the thickness of that insulating layer, and in some cases, their comical appearance!

OK, but how can birds stand on ice and not have their body temperature plummet? Some birds have specialized scales on their feet and legs to help insulate them. Their anatomy can also help via a phenomenon known as counter-current exchange. This is an exchange of heat which occurs when the arteries carrying warm blood from the heart are in very close contact with the veins carrying cold blood from their feet. The cold, heart-bound blood is thus warmed up, helping the bird maintain a stable core temperature. Interestingly, the same counter-current exchange mechanism helps birds tolerate the other heat extreme (recall my mention of boiling up above.) When we lived in Kenya I often wondered “How can those flamingos stand in near-boiling hot springs?” The temperature of very warm veinous blood from their legs is reduced when it races upward in close proximity to the cooler arterial blood coming down from their hearts!

There are other simple ways that birds change their behavior to stay warm. Some tuck in their bills and legs in to keep them warm. Others huddle together. I recall one night seeing six Swallow-tailed Bee-eaters packed like sardines on a branch in Kgalagadi Transfrontier Park. They were trying to stay warm in that desert locale where winter temperatures can be in the seventies or eighties during the day but can dip well below freezing at night.

Another challenge for birds this winter has been finding food when so much of the water and ground is frozen. An obvious behavioral response is to fly to a more suitable habitat. For many birds this means flying (further) south. For others it means flying from frozen-over ponds and lakes to very deep, unfrozen lakes or to flowing rivers, like parts of the Potomac River. I was surprised last month to see several Wilson’s Snipe just upstream from the Potomac at Hunting Creek Bridge, but it was one of the few places around with unfrozen mud! And another day, from one spot along the Potomac River in Alexandria I saw Hooded, Common, and Red-breasted Mergansers, species not normally found together, but all brought to a rare ice-free spot where they could dive for fish.  

Another way birds find food in such frigid times is by locating birdfeeders. My husband tends several feeders in our back yard which have brought in more than two dozen species in winter, including a Cooper’s Hawk. The hawk is not after the seeds because it eats birds and small mammals. Its normal behavior has been to hunt our birdfeeder-visiting birds from a nearby tree, but on one snowy and windy day in late January it was sitting just two feet above the feeders. Perhaps the cold had altered its behavior as well, and it had decided it was too cold for stealth!

Tundra Swans

Photo: Tundra Swans, Kent Blumberg

Kent Blumberg

You still have time, if you’re lucky, to see one of our most spectacular winter visitors: the Tundra Swan (Cygnus columbianus). Hundreds of these graceful white birds spend the winter in the Chesapeake Bay and tidal Potomac from November through mid-March. When they gather in large flocks, the sight is unforgettable.

There are two native swan species in North America: the Trumpeter Swan and the Tundra Swan. Tundra Swans are far more numerous and are the species that winters with us.

Tundra Swans. Photo: Mitzi Gellman/Audubon Photography Awards

Tundra Swans are large birds, weighing up to 20 pounds. They are 47 to 58 inches long with an impressive wingspan of six to seven feet. Their bodies are bright white, with black beaks and feet. Most adults have a small yellow spot on their bill near the eye, although this can vary. Juveniles are grayer, as if they forgot to wash after a long day playing outside. 

Tundra Swans are dabblers, meaning they submerge their heads and necks to pull up underwater vegetation and roots. 

They are monogamous, often courting for months before mating for life. Once paired, they usually stay together for life and migrate, feed, and raise young as a couple.

Breeding occurs in the far north of Canada and in western and northern Alaska. Each pair has one brood per year, incubating the eggs for 31 to 40 days. Cygnets are precocial, which means they can walk within hours of hatching. Their first flight is typically within 60 to 70 days. And that first flight is just a teaser for what’s to come.

In the fall, just before their breeding grounds freeze, family groups begin their long migration. They spread those huge wings and fly over 4,000 miles south and east to visit us. The journey can take nearly three months.

Swans begin to arrive here in November. This season’s first eBird report at Elizabeth Hartwell Mason Neck NWR was on November 13, 2025. At peak winter numbers, flocks can reach several hundred birds. One checklist on December 29, 2025, for example, counted 460 swans. I first saw them just one year before that, on December 29, 2024: a cold, sunny morning and a perfect way to end the year.

If you’d like to see them, check eBird for recent reports. Two trails often provide excellent viewing opportunities at Elizabeth Hartwell Mason Neck NWR. The Woodmarsh Trail is undulating and bumpy, with a large, covered viewing platform just over a mile from the parking lot. The Great Marsh Trail is paved, with an observation platform about three-quarters of a mile from the start. Try to visit around high tide, when the swans are more likely to gather where you can see them. Bring binoculars, a scope or a camera with a telephoto lens to get the best views.

If you miss this year, mark your calendar for late November and start watching eBird. The swans will be back.

You can read more about Tundra Swans on a number of Cornell Lab websites: eBird, All About Birds and Birds of the World. Another resource is the U.S. Fish & Wildlife Service, which chose the Tundra Swan as its February 2024 Bird of the Month.

Kent Blumberg is an MBA professor, passionate bird photographer and voracious reader. 

The Latest on Avian Influenza

Photo: Green-winged Teal, Gary Zahm/Audubon Photography Awards

Brad Scriber

Spring migration is about to bring millions of birds north along the Atlantic Flyway, a welcome sight for Virginia bird-lovers emerging from a season of persistent cold and stubborn snowbanks. With these birds, concern is also returning about a bird flu outbreak that has been active in the U.S. since early 2022. Overall, the public health risk from the virus is low, but for certain animals and people who are likely to encounter infected birds, precautions remain important. 

Bird flu, also known as avian influenza, is a broad term for illnesses caused by a family of viruses with varying impacts on different bird species. Wild aquatic birds are reservoirs for these pathogens, which means they often carry the germs but don’t get sick. Sometimes mutations and other changes in the virus populations circulating among these birds can create new strains that do cause severe symptoms or death for these host birds. Whether or not a strain makes an aquatic bird sick, the virus can be passed on and infect poultry flocks or wild land-based birds, which may have stronger reactions. Viruses are spread through direct contact or indirectly through saliva, mucus, or feces. 

If you See a Sick or Dead Bird

Experts say not to handle sick or dead birds. If you must remove a carcass, wear protective gear (rubber gloves, a mask, and eye protection) and bury the dead bird or double bag it and place it in a secure, trash can to prevent scavengers from accessing it. Call the Virginia Wildlife Conflict Hotline at 855-571-9003 or email wildlifehealth@dwr.virginia.gov if you see:

• Five or more dead vultures, waterfowl, shorebirds, or seabirds in the same area within five days

• Sick or dead eagles, hawks, owls, or turkeys, excluding carcasses found on the road

• Ten or more dead wild birds of any other species in the same area within five days

Suspected cases in backyard poultry flocks should be reported to the Virginia State Veterinarian’s Office at (804) 692-0601 or at vastatevet@vdacs.virginia.gov. You can also call the USDA toll-free at (866) 536-7593 to report suspected cases in wild or domestic birds.

Atlantic Flyway Wild Bird Infections

USDA tracking of wild bird infections shows that in the early weeks of 2026, a number of Canada Geese, Bald Eagles, crows, and Red-tailed Hawks have been found with bird flu in Fairfax County, Loudoun County, and Alexandria. Last fall, birds killed by hunters across Virginia tested positive across many species including Green-winged Teal, Ring-necked Ducks, Greater Scaup, Gadwalls, and Mallards. 

Bald Eagles. Photo: David Rein/Audubon Photography Awards

Predators and scavenger birds likely ingest the virus while feeding on infected waterfowl. Raptor infections are raising concern about the impact on population dynamics. Infected waterfowl deaths overlap with peak Bald Eagle nesting season from North Carolina to Florida and may be hindering breeding success and the recruitment of maturing birds into Bald Eagle mating populations. Some infected eagles have been observed dropping from their nests or have been found dead directly below active nesting sites.

High Risk to Farm and Backyard Poultry

Scientists tracking bird flu use the terms highly pathogenic avian influenza (HPAI) or low pathogenic avian influenza (LPAI) based on how aggressively a virus infects and kills chickens during lab testing. The virus of concern at the moment, known as H5N1, is an HPAI virus with significant risk to backyard and commercial poultry. According to an archived CDC article, the current H5N1 virus is descended from a virus that caused serious concern thirty years ago. A version of the H5N1 virus was found in domestic waterfowl in China in 1996 and caused an outbreak in poultry the following year, which eventually led to human deaths. After a lull, when cases were rarely detected, outbreaks returned in various parts of the world, eventually reaching North America.

Turkeys at a commercial facility in Indiana tested positive for the current strain in February 2022, one month after the first such infection was detected in wild birds in the United States. This broke a bird flu clean streak for the country, which had detected no infections in commercial poultry since 2020, and none in wild birds since 2016. Almost 200 million poultry have been affected since that 2022 detection, touching every state and Puerto Rico. A total of 1,137 backyard flocks and 943 commercial flocks have seen cases.

Hardest hit for the overall outbreak has been Iowa, where more than 30 million birds have been affected, but in the past month, Pennsylvania has seen the highest numbers nationwide. More than 7 million Keystone State birds have been affected in the past month, most of which were commercial egg layers in Lancaster County. The outbreak is a major reason that egg prices have soared in recent years.

Birdfeeders Are Okay, Unless You Raise Chickens

Unless you have backyard poultry, experts say there is no need to remove birdfeeders, although keeping them clean and hygienic is good practice.  

The risk of a songbird passing the virus to another songbird is small. They are less likely to carry the virus than water birds and less likely to become infected if exposed. However, because chickens and other poultry are extremely susceptible to infection and contagion from this strain of flu, even a rare instance of a sick bird visiting a feeder where poultry are present could put the resident backyard flock in danger.

Spread to Other Animals 

The USDA tracks cases of HPAI infections in mammals of all species. It has occurred in lions, tigers, and bears, among others. Mice and rats, minks and lynx, seals and dolphins, and other animals have been found to carry the virus. Cattle are of particular concern, and the USDA has found more than 1,000 infections across 19 states, mostly in the west, but also as close as North Carolina and Ohio.

In our area, three foxes in Loudoun County tested positive in 2025, as did a black bear found in North Carolina in 2022. In Pennsylvania, foxes have also tested positive for the virus, and in March of 2025, a domestic cat was found to be infected.

Cats, like raptors, can be exposed to the virus by eating infected birds. They can also catch it from eating raw milk, meat, or poultry, or exposure to infected farm animals or humans. Early symptoms include fever and lethargy, progressing to difficulty breathing, lack of coordination, and seizures. Up to 70 percent of infected cats die from the illness.  

Spread to Humans Mostly Among Food Industry Workers 

The CDC is actively tracking the bird flu, and has found 71 cases of the disease in humans, with two fatalities. Almost all of these cases have been among dairy and poultry industry workers, with the highest concentrations along the west coast. Veterinarians also risk coming into contact with infected animals and should take precautions.

The overall current public health risk is low, and there have been no cases of person-to-person spread. 

Brad Scriber is an Arlington-based writer, researcher, and bird buff.

Their Time to Sleep

Photo: Winterberry in snow, Margaret Fisher

Eileen Ellsworth

It’s March. Spring is coming, but when you glance outside it’s still cold and dark, sometimes snowy. But the marvel of plant dormancy is once again unfolding, unseen. Plants need their rest and recuperation. It’s an annual phenomenon, a common thing, but that doesn’t make it any less of a miracle. 

Dormancy in plants is ancient. While estimates vary, seed dormancy emerged roughly 360 to 370 million years ago and seems to have developed at the same moment seed-bearing plants arrived. The strategy allowed the early seed plants to survive the more lethal environmental perils. Their ability to push “pause” whenever extreme cold, drought, flood, or any other earthly or celestial catastrophe occurred gave them a huge advantage. Plants could wait out the worst and only wake up when conditions were better.  

How long, exactly, can a seed lie dormant? It’s a good question. Most of our garden plant seeds are probably good in the ground for 1-5 years. After the recent California wildfires, certain “fire-follower” species germinated after 100 years of dormancy and bloomed in large carpets of spectacular color across the landscape. Some documented lotus species whose seeds enjoyed optimum storage conditions sprang back to life after 1,300 years!

No one actually knows how long a seed can lie dormant and remain viable. But it really doesn’t matter. The sheer brilliance of an adaptation that allows a plant to literally pick its go-time is mind-boggling when you think about it. Wish we could do that.

And, of course, plant dormancy goes well beyond the realm of seeds. There is “bud dormancy” triggered by shorter days and cooler temperatures that makes trees and shrubs want to stop growing and shed their leaves. There is “organ-dormancy” forcing above ground rest in some perennials. There is a kind of “pseudo-dormancy” where plants are poised to grow but pause due to unfavorable environments. There is a hibernation-type dormancy that enables plant survival in extreme heat or drought. And so on.

Winterberry in snow. Photo: Margaret Fisher

Many strategies, one goal. Keep living. And it is lucky for us that they have. With ancient bacteria as their partner, they figured out how to photosynthesize and turn water and carbon dioxide into glucose and oxygen. They are the reason we can exist, why our cells have glucose to fuel them, why our lungs have oxygen to breathe. Plants, not animals, are the reason this astonishingly beautiful planet is still blue, emergent, and alive.

Our dependency upon their health certainly calls us to be the best possible stewards of the land. There is no doubt that planting and preserving native plants directly advances the goal of restoring biodiversity across our region. Only their magic can do it. The Plant NOVA Natives campaign and NVBA’s Wildlife Sanctuary Program are all about that, and their websites have all you need to know to take action.

Even in the dead of winter, let’s hear it for the plants! Let’s cheer them on and wish them well as they sleep. We owe them everything. They’ve earned their rest. Lay dormant, dear friends. Pick the time when all is well and come to greet us again. We hope it’s soon. We love you so. We couldn’t live without you. 

Invasive Plant Legislation Moves Forward in the Virginia Legislature

Photo: Invasive vines, Valerie Morgan

Tom Blackburn

Anyone who walks in local parks or drives the highways can see invasive plants overwhelming trees, shrubs and meadows. Invasive plants are estimated to cost the state $1 billion per year. I am pleased to report that the Virginia legislature appears to be intent on taking steps to slow the environmental and economic harm that invasive plants are causing. State legislators introduced seven bills relating to invasive plants in the 2026 legislative session, and all of them are proceeding through the legislative process. 

Invasive vines smothering a tree. Photo: Valerie Morgan

Local government control of invasive plants: House Bill 388 and Senate Bill 89 are essentially identical bills that would permit local governments that have established service districts to use tax revenues to control the spread of plants on the state’s list of invasive plants. The House and Senate each has passed its bill by unanimous vote, meaning that it is virtually certain that the bills will be consolidated and sent to the Governor for signature. Congratulations to the Fairfax Invasive Removal Alliance, which first championed this bill and convinced other environmental organizations to support it. 

Ban on selling state-designated noxious weeds: Current law allows retailers to sell plants included on the state list of noxious weeds, even though they are the most destructive of the invasive plants, if they are commercially viable. As introduced, House Bill 109 would have banned the sale of noxious weeds outright. However, the House passed the bill by a vote of 96 to 2 with an amendment that phases in the ban over two years for grasses, forbs, and vines; four years for shrubs; and seven years for trees. The Senate Agriculture, Chesapeake and Natural Resources Committee reported the bill to the Senate, where it is awaiting final action. 

Ban on invasive plants along state highways: House Bill 88 would prohibit the Commonwealth Transportation Board and Commissioner of Highways from planting any plant on the state list of invasive plants along any state right-of-way. As introduced, the bill would have required the state to establish a plan for the removal of all invasive plants from the right-of-way, but that provision was removed from the bill before the House passed it by a unanimous vote. Two Senate committees have reported the bill unanimously, and it is now pending before the full Senate.

Civil fines for failing to notify landowners before planting invasive plants: House Bill 710 and Senate Bill 383 are essentially identical bills that establish civil penalties for tradespeople who propose or install plants listed on the state’s invasive plant list without first notifying the property owner in writing. The House bill passed with only two dissenting votes and the Senate bill passed unanimously. It is virtually certain that a consolidated bill will be sent to the Governor for signature.

Volunteers’ using herbicides on state property: In the last session of the General Assembly, the legislature passed and the Governor signed legislation permitting volunteers under supervision of a certified applicator to use herbicides on property owned by local governments. Senate Bill 163 would expand that law by making it applicable to state-owned property. The bill passed the Senate by unanimous vote and the House Agriculture, Conservation and Natural Resources Committee has voted unanimously to send the bill to the full House for a vote. 

Next steps: House Bills 88 and 109 must be passed by the Senate and Senate Bill 163 must be passed by the House before they can be sent to the Governor for signature. 

A big thank you to the 28 members of NVBA’s Advocacy Committee and other NVBA members who have agreed to write to their delegates and senators to support environmental legislation. We will continue to write to our legislators about these three bills and other bills that preserve and enhance our environment.

This story was updated on Wednesday afternoon, February 25. For further developments on the bills, go to the Virginia Legislative Information System and type the bill number into the search box identifying the chamber (HB or SB) and the bill number.

The I-95 Landfill’s Becoming ‘Birdy’

Photo: No-mow Area, Glenda Booth

By Glenda C. Booth
Reprinted with Permission of the Connection Newspapers

50-acre no-mow grassland provides sanctuary for some bird species of concern.

Few people find visiting a landfill enticing, but some of our avian friends do.

Grassland and other birds are using a closed portion of the I-95 landfill, according to a recently released Fairfax County report.  

In 2024, at the urging of the Northern Virginia Bird Alliance and with the Board of Supervisors’ support, landfill managers designated 50 closed acres of the 500-acre landfill as a “no-mow” zone. The managers agreed to avoid mowing during grassland birds’ nesting season and to raise mower blades to an eight-inch height when they did mow.

The no-mow zone continues to provide critical habitat during the peak breeding and nesting season, attracting birds like the Eastern Meadowlark, above, and Grasshopper Sparrow. Photo Courtesy of Fairfax County Department of Public Works. 

County officials concluded, based on 2024 and 2025 surveys, that “overall observations confirm that the no-mow zone continues to provide critical habitat during the peak breeding and nesting season.” County staffer Kimberly Lewis wrote, “The eastern meadowlark and grasshopper sparrow, among other species, are thriving on a 50-acre meadowland atop the landfill.”

By modifying and reducing mowing, the area is in effect a grassland, albeit not a natural one. The project sought to determine which grassland birds are using the area and how.

In 2025, Blair Evancho, a county intern, staffers and volunteers conducted weekly bird surveys from May 1 to July 12 and recorded all bird species observed. They confirmed 40 bird species in this area in 2025, including four species of regional or continental concern: chimney swift, grasshopper sparrow, eastern meadowlark and bobolink. “Notably, the grasshopper sparrow, a grassland nester experiencing regional population declines, was the most detected species,” notes the county’s report. In 2024, surveyors confirmed 29 bird species.

“The County’s monitoring efforts show that the I-95 Landfill Complex continues to provide meaningful habitat for grassland birds, including several species of conservation interest,” commented Duane Wright, Director, Solid Waste Management Program. “These findings reflect our commitment to thoughtful land management that supports both environmental stewardship and long-term site care.” 

“On survey days, at least one Northern Virginia Bird Alliance (NVBA) volunteer helped,” NVBA President Libby Lyons said. “We commend the County for this approach and hope this project can serve as a role model for other landfills in taking such important conservation steps,” she said.

According to the 2025 report, one glitch was “unanticipated mowing on three days in June during work on a new solar field next to the no-mow zone, which created “a noticeable decline in bird activity on those dates.” The report indicates that this mowing “conflicted with the established protocol, which prohibits mowing in the no-mow zone during the April-September breeding season, except when required for access to monitoring wells.”

No-mow area. Photo: Glenda Booth

Grassland Birds

Grassland birds rely on grassland habitats for nesting and many species have seen marked drops in numbers. Since 1970, grassland birds have declined by 43 percent, concluded the 2025 State of the Birds report by the North American Bird Conservation Initiative. The main driver is habitat loss.

Most of the eastern United States’ natural grasslands are gone. These birds typically do not use other habitats. In Virginia, since the European colonists’ arrival in the 1600s, only a fraction of the state’s grasslands remains. “It may be less than .0001 percent,” according to biologist Justin Folks, quoted on the Virginia Outdoors Foundation’s website.

“The landfill has the largest patch of grassland in eastern Fairfax County,” ornithologist Greg Butcher said in our 2024 Connection article. Landfill managers usually put a cover on closed landfills and plant grasses to stabilize the surface.

Wright concluded, “By maintaining a clearly defined seasonal no-mow period, the County is able to support important nesting and foraging activity while also ensuring the landfill remains well maintained and protective of the environment. This balanced approach allows us to responsibly manage closed landfill areas while recognizing their value as part of the region’s broader ecosystem.”

Help Rescue Fairfax County Trees

Photo: Invasive vines on trees, courtesy of Fairfax Tree Rescuers

Margaret Fisher

Fairfax Tree Rescuers PRISM (Partnership for Regional Invasive Species Management) has organized a Spring Tree Rescuer Extravaganza, with events scheduled March 21 - April 12. Participants are encouraged to celebrate the end of winter by getting out in the fresh air to clip the invasive vines or dig up other invasive plants. Registration is required. Keep checking the website listed above as more events are scheduled. 

A Closer Look: Nature All Around Us, March 2026

Photo:  Laphria affinis robber fly with lady beetle prey, Judy Gallagher

Judy Gallagher

March 2026

I once heard robber flies described as the raptors of the insect world. As the name implies, they are flies, and according to iNaturalist, they are called robber flies because of their expert predatory habits. They usually sit in an open area, watch for insects to approach, fly out to catch them and then return to their perch to finish their meal. 

Robber flies typically have a long abdomen and spiny legs which aid in prey capture. Some appear to be humpbacked, and many robber flies have mustaches called mystax, which may help protect the head and face when prey tries to fight back. Their wide-spaced compound eyes give an extensive range of view and they have long, pointed proboscises that they use to inject neurotoxins and digestive enzymes into prey. There are approximately 7,000 robber fly species worldwide, with about 1,000 species in North America. 

Microstylum morosum, North America's largest robber fly. Photo: Judy Gallagher

Most robber flies are between 1/2 inch to 3/4 inch long, but North America's largest robber fly, Microstylum morosum, can be 2 inches long, and a species in Madagascar is more than 3 inches long! 

Laphria partitor, a bumble bee mimic. Note its impressive mustache (mystax). Photo: Judy Gallagher

Some robber flies are bee and wasp mimics, with black and yellow striped patterns. They sound like bees and wasps, making loud buzzing sounds as they fly. A number of robber flies in genus Laphria resemble bumble bees, and even have yellow fuzz just like bumble bees. 

Robber flies mating, while one dines on wasp. Photo: Judy Gallagher

Robber fly males are territorial, chasing away rivals before trying to court the female. Males of some species conduct aerial displays to attract females or offer the female a "nuptial gift" of captured prey. Robber fly females have been known to play dead if they are not interested in the male's advances. 

Robber flies that hunt on the ground tend to lay eggs on or in soil, and robber flies that hunt from plants usually lay their eggs in plants. The grub-like larvae live in soil, rotting wood or other decaying materials and, like the adults, are predators.  

Robber Fly with Eastern Amberwing (dragonfly) meal. Photo: Judy Gallagher

Most adult robber flies attack prey that is smaller than they are, but there are exceptions, like the robber fly that attacked the dragonfly in this picture. The heavier dragonfly caused the pair to crash on the ground. After the robber fly finished its meal, it flew off, presumably to find another meal. 

They consume a significant portion of their body weight each day, but the number of insects consumed depends on the weight of each prey item. Some robber flies specialize in prey like grasshoppers, but most are generalists. 

Laphria affinis robber fly with lady beetle prey. Photo: Judy Gallagher

You might wonder if robber flies could be a useful biological control of pest insects. The answer is, "It depends." Yes, they eat pest insects, but they are not always discriminating in their diet, and they eat useful insects like lady beetles too. 

Hanging-thief with wasp prey. Photo: Judy Gallagher

Robber flies in genus Diogmites are known as hanging-thieves because, after capturing prey, they feed by hanging from plant stems or leaves suspended by one or both front legs. The other legs hold and manipulate the prey. Hanging-thieves mostly prey on Hymenoptera (wasps, bees, etc.) and can negatively impact honey bee populations. The female lays eggs in the ground, and her ovipositor has spines that aid in covering up the eggs. 

Gnat Ogre with prey. Photo: Judy Gallagher

As the name suggests, Gnat Ogres mostly prey on gnats, although the one pictured here has a tiny wasp instead. Most gnat ogres are small, between 1/8 and 3/8 inches long, and perch on vegetation tips to hunt. 

Although robber flies are known for their impressive hunting skills, they can also be prey. Robber fly predators include birds, lizards, frogs, bats, jumping spiders, dragonflies and parasitic wasps.

When spring finally arrives, I hope you can observe one of these magnificent hunters in action.

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View more of Judy’s articles on A Closer Look: Nature All Around Us (formerly Observations from Meadowood).

Wildlife Sanctuary Almanac: It's Spring! Is it Time to Plant?

Photo: Mertensia virginica (Virginia Bluebells), Cbaile19, CC0, via Wikimedia Commons

Alda Krinsman

Spring arrives on March 20. Those occasional warm sunny days that occur in early spring may signal that it is time to add to your native plant gardens. But don’t move too fast! Despite their reputation for being able to adapt to our local climate conditions, even native plants, when newly planted, can be damaged or killed by frosts or freezes that occur after the first day of spring. 

Rather than the first day of spring, the best date to use as a guide for spring planting should be the average last frost date, which varies by specific location. In northern Virginia, this date in 2026 can vary from April 1-15 in Alexandria to April 15-25 in Winchester.

Fragaria virginiana (Wild Strawberry). Photo: Walter Siegmund, CC BY-SA 3.0, via Wikimedia Commons

Chrysogonum virginianum (Green and Gold). Photo: David J. Stang, CC BY-SA 4.0, via Wikimedia Commons

If you plan to order native plants online, it would be best to request a shipping date after the average last frost date in your area. This is especially true if the grower is located in an area with an average last frost date that is earlier than that in your area. You want to avoid shocking plants that may be starting to emerge from dormancy by having them arrive in an area still at risk of frost or even freezing. As noted above, average frost dates can vary throughout the DMV, so even if you purchase native plants from local growers at sales in March and April, it would still be wise to hold off planting until the last average frost date for your specific locale.

Once your average last frost date has passed, also consider the soil conditions before you plant. The soil where you plan to plant should be workable. Soil conditions can vary throughout your property. If the soil is still frozen, it is too early to plant despite the air temperature. Soil in some areas of your property may still be frozen even after the last average frost date, especially in areas in deep shade. Also consider the moisture level of the soil. If water pools in the hole as you dig, it is still too early to plant. If you grab a handful of soil and it clumps and even drips when you squeeze, it is too early to plant. Planting in wet soil will compact the soil. Compacted soil deprives plants of oxygen and interferes with root growth, which can be fatal for your plant. If the soil crumbles and falls apart in your hand, it is workable, and if the last average frost date in your area has passed, it is probably safe to plant. As a final precaution, it would be wise to check the 10-day forecast for your area to ensure there are no unusual frosts or freezes predicted.

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Catch up on past Wildlife Sanctuary Almanac articles here.

Letter to Our Members: Flickers of Hope in Winter

Photo: Northern Flicker, Barbara Tomawski/Audubon Photography Awards

Danielle Brigida

Years ago, I visited the bird banding station at Patuxent Research Refuge, and one of the birds we caught was a Northern Flicker. I’d been birding for about five years, but banding was new for me and exhilarating in a way I hadn’t expected. Seeing birds up close collapses a distance you don’t even realize exists.

Northern Flicker wing, Danielle Brigida

I’ll never forget that bird. I’d been enjoying watching flickers, confidently thinking I knew them. But holding one, and extending its wing feathers, I gasped. He was so vibrant. What were normally just flashes of color were shockingly vibrant up close. The bird I thought I understood suddenly revealed itself as something far more magnificent.

Moments like this are part of what keeps me birding . . . a small observation that shifts into something deeper. Not just recognition, but awe. A swell of appreciation that keeps me coming back to the birds. Even when times are hard. Even when much of the news we’re reading is devastating.

And that’s the thing about flickers and about noticing birds. Their presence can be just as easily overlooked as it can be celebrated.

Woodpeckers, in particular, are marvels of specialization. Their skulls are reinforced to absorb shock, their brains cushioned to withstand repeated impacts. Their feet are zygodactyl with two toes forward, two back—perfect for gripping bark, while stiff tail feathers act like a built-in kickstand, bracing them against vertical surfaces. Even their tongues are extraordinary, long and barbed, wrapping around the skull when retracted and extending far beyond the bill to spear insects deep in crevices.

Even though Northern Flickers are woodpeckers, they don’t behave quite like the others. You’re just as likely to find one on the ground as on a tree, probing the ground for ants—a preferred food. 

When flickers take off, that bright white rump flashes like a white flag, and when the wings open, the underfeathers glow—yellow in the East, red in the West. They’re birds of edges and openings, and they can be found on forest margins, open woods, parks, golf courses, and yards. In winter, especially, listen as much as you look. Their one-noted shriek that sounds like “peough” can carry through leafless trees. I've found their bounding flight becomes recognizable over time. And when the woods are mostly brown, that sudden glimpse of yellow feels like a welcome burst of light.

Northern Flicker, Jennifer Miner/Audubon Photography Awards

During banding, it was the first time I noticed that at the right angle, some shapes in the flicker's feathers look like hearts. Which makes northern flickers feel like the perfect bird for a season when we need both more sunshine and hearts. I think about them every Valentine's Day.

To spot them, listen for their shrieking call or scan areas for a Blue-Jay-sized, brown, spotted bird standing upright on the ground.

Working to help birds, I cherish moments in the field. It's a reminder that helping science and volunteering is about more than contributing additional data. It sharpens your noticing. And suddenly you realize there are flickers of hope everywhere.

NVBA Helps Preserve Urban Forest in Fairfax City

Photo: View of the path of the proposed trail, Val Morgan

Tom Blackburn, Chair, Advocacy Committee

Following a long and hard-fought campaign by environmental advocates, the Fairfax City Council voted not to proceed with constructing the George Snyder Trail, which would have destroyed much of the city’s urban forest. This victory for the environment over development is a classic demonstration of the effort needed to secure an environmental “win.” 

First proposed in 2015, the George Snyder Trail project was envisioned as an at-grade natural surface or stone dust trail between Chain Bridge Road and Fairfax Boulevard costing about $200,000.  City staff revised the plans to make the trail eligible for funding from a concession payment to the state by the contractor who widened I-66. The result was a radically different asphalt trail 8 feet wide with only 1/3 of the trail on existing terrain, and the rest on boardwalks, bridges, excavations and fill dirt. The projected cost of the 1.8-mile trail exceeded $20 million. 

Despite an almost total lack of public notice, opponents of the trail, including the Friends of Accotink Creek and others, began mobilizing in 2018. Katy Johnson, who subsequently joined NVBA’s Advocacy Committee, was a key figure in organizing opposition. The opponents pointed out that the “free money” from the award of concession payment funds came with a substantial environmental cost, including the loss of 600 mature trees and thousands of smaller trees, and the destruction of much of the forest ecosystem and topsoil because of the construction and equipment needed to build the trail. They also  explained that alternatives to the trail on existing trails and low-use neighborhood streets would avoid nearly all the environmental damage.

NVBA formally joined the opposition in October 2023 when I, on behalf of NVBA, testified using as the theme Joni Mitchell’s song “Big Yellow Taxi” (“They paved paradise, put up a parking lot”). Katy Johnson, Virginia Native Plant Society’s Potowmack Chapter, A.E.R.O., Climate Action Now, many residents and NVBA joined the earlier opponents of the trail in testifying at several Fairfax City Council hearings. They explained the importance of the mature oak-beech forest ecosystem, detailed the extent of the destruction the trail would cause, analyzed the number of additional trips on the trail by people who switch from driving to biking that would be needed to offset the loss of carbon sequestration from the destroyed trees and pointed out the impact on flooding in Accotink Creek from the loss of trees that absorb groundwater. They also addressed claims that if the city canceled the project it would have to repay $4 million that the Virginia Department of Transportation had spent on project design and related costs. 

The issue was resolved on January 13, when the City Council voted on whether to appropriate an additional $4.6 million in VDOT concession funds for the trail. The appropriation was needed because the lowest bid for construction was $4.6 million higher than the previously approved appropriation. NVBA joined other environmental groups and individuals in testifying in opposition to the trail, and numerous supporters of the trail testified as well. You can read NVBA’s testimony, which includes photographs, and outlines the extent of the damage to the forest that would result from constructing the trail above and below ground here. The Council voted 3-3 on the motion to appropriate the additional $4.6 million. Because a majority vote was needed to approve the appropriation, the motion failed. The council then voted to notify VDOT that the trail had been canceled. 

The dispute over the George Snyder Trail highlights the difficulty of balancing the need for trails for recreation and commuting against protecting the environment. NVBA has attempted to address the environmental issues associated with trails through natural areas by developing criteria for evaluating bicycle and multi-use trails, which you can read here. It also demonstrates the importance of conducting careful environmental reviews of proposed trails through natural areas before substantial design work has been completed – something that was not done for the George Snyder Trail.  Finally, it serves as a reminder that continued vigilance and sustained involvement are critical to protecting our environment.