Copperheads in Fairfax County

Garter Snake 11Garter Snake

Maybe it goes back to Adam and Eve, this fear of snakes that humans often have; that and the fact that we generally don’t like things to bite us. But if you take the time to learn about snakes, that fear might diminish when you realize it’s just another animal that eats, poops, moves around and makes little babies like the rest of us. Okay, maybe they don’t put their pants on one leg at a time like you and me, but you get the point.

Fairfax County Park Authority nature centers are convenient local places to learn about snakes. Among the things you’ll learn – Northern copperheads are the only venomous snakes in Fairfax County. Rattlesnakes are as close as Bull Run Mountain in Prince William County, but water moccasins are centered near the Hampton Roads area of Virginia.

Northern copperheadNorthern Copperhead

Copperheads are rather heavy-bodied snakes and are beautifully marked with dark brown, hourglass-shaped cross bands on a light tan or gray background. Adult snakes are usually two to three feet long, and the belly is a mix of white and black markings. They are eight to ten inches at birth, about the size of a pencil.

Baby copperheads look just like their parents, but they have a bright yellow or green tail that they wiggle and use to lure lizards and frogs within striking range. Like other pit vipers, copperheads have a triangular head with facial pits and vertical pupils, just like a cat.

Northern water snakeNorthern Water Snake

Non-venomous snakes are often mistaken for copperheads, especially the Northern water snake and Eastern rat snake. If you see a patterned snake totally submerged in water, chances are it is not a Northern copperhead.

Copperheads are most active at night but also can move around or bask in sunshine during the daytime. In the hot summer, the woods are quite barren compared with our lush, irrigated yards, and various food sources around homes can easily draw rodents and snakes to your neighborhood.

What about snake bites?

The clear majority of snake bites occur when snakes are deliberately handled or poked by curious humans or curious pets.  The Johnson Lab at the University of Florida says about 7,000 to 8,000 people are bitten by venomous snakes in the U.S. each year. That’s fewer than one strike for every 37,500 people.  Typically, unless you accidentally contact a snake, you can avoid being bitten by maintaining a respectful distance from any snake that you see. In short, if you see one, just stay away from it. Most snakes will remain motionless when you come upon them and will allow you to pass by safely. The best precautions you can take are to wear proper footwear, such as closed-toe shoes on trails, wear fitted gloves when gardening or clearing areas of heavy foliage, and don long pants. Be aware of rock or wood piles outdoors. Snakes may hide there. Snakes also can be hard to see in tall grass and under ground cover such as invasive English ivy.


About a decade ago, I was bitten by a juvenile copperhead snake with a bright yellow tail. I was walking my dog at dusk on an asphalt trail through a wooded suburban park wearing flip-flops, and I probably stepped directly on the snake. It was just after a heavy storm, and leaves and mulch were scattered on the pavement, making the snake difficult to see. The snake bit me just below the ankle. I probably could have prevented a bite if I had been wearing any kind of hiking or athletic shoe. As an ecologist, I always wear proper footwear and clothing when I’m in the field, but I had let my guard down since I was at home in my own neighborhood. This taught me to take the same basic precautions whenever in the outdoors. If you or a pet are bitten by a venomous snake, seek immediate medical treatment. I received anti-venom at the hospital and have no lingering effects from the bite.

When not dealing with an emergency, if you get a photo of a snake and would like it identified, take the photo to a nature center or email  Staff will gladly try to identify the snake and share information about why it was where you saw it.

The Virginia Herpetological Society is a good source of information about snakes in Virginia.

Author Kristen Sinclair is an Ecologist with the Fairfax County Park Authority.

Sully Takes Swift Action to Protect Migratory Birds

Sully Birds157Sully Historic Site has new residents. More than 200 years after the first residents moved in, a new family calls it home. Chimney swifts have lodged in, well, the chimney of Sully’s original 18th century kitchen. Their temporary nesting site selection means there will be programming changes at the historic park.

Sully chimney Swallow_080118_0017Chimney swifts are protected by the Migratory Bird Treaty Act of 1918. It’s illegal to disturb them, their nests or their eggs. To protect the birds for the next six to eight weeks, Sully will make some changes. For one, no fires in the fireplace until they leave.

sully-birds162.jpgTaking photos of Sully’s new residents

Sully’s original kitchen hearth and chimney have been usable for centuries, and kitchen programs often include a hearth fire demonstration. To prevent disturbing the birds’ nesting cycle, no fires for the time being. Sully’s primary focus is the preservation of the site’s historic structures and resources, but as part of the Fairfax County Park Authority, there’s pride in the responsibility of protecting natural resources, too.

When they do leave this fall, the chimney swifts will use their stiff, nearly non-stop wingbeats to carry them to Central America, Peru or elsewhere in South America’s Amazon Basin. While they are here, you might spy them flying over towns or across bodies of water. They seldom rest, and they can only hold onto vertical surfaces because of their long claws. The Cornell Lab of Ornithology says the population of these “flying cigars” rose when Europeans brought building styles that included chimneys, and those numbers may fall again as we shift to covered, narrow flues.

To learn more about swifts, stop by any of Fairfax County Park Authority’s five nature centers for a visit.

Sully Historic Site is located at 3650 Historic Sully Way, Chantilly, VA 20151, off Rt. 28 (Sully Road), ¼ mile north of Rt. 50 and five miles south of the Dulles Toll Road. Get information about Sully online at or by calling 703-437-1794.

Invasive Species Spotlight: English Ivy

DSC_0008It is often described as a lovely, evergreen groundcover. It is also a damaging, invasive species.

English ivy is widely planted, probably ever since ornamental plants were first imported to the United States. Because it is a ground-covering vine that smothers anything in its path, English ivy has been linked to the loss of plant diversity. Winter is the time of year that Hedera helix, or English ivy, makes its presence known. It stays green all year, which is probably one of the reasons why county residents like it in their yards or climbing their mailboxes. English ivy also stands out in natural areas during winter and often is the only green in the forest after native plants have died back for the year.

DSC_0010English ivy is especially dangerous to trees. Once the vine reaches branches, its extra weight can cause those branches to break, injuring the tree and opening an entry point for pathogens or fungus infections. Even if the tree can manage the extra weight from the vines, English ivy will eventually cover all the branches, shading leaves and leading to the tree’s death. English ivy growing on private property can spread to natural areas where it can grow unchecked.

DSCN1481Invasive species are widely considered to be the second-worst cause of ecosystem function degradation. The first is habitat loss, however, invasive species and habitat loss often go hand in hand. To learn more about invasive species removal in Fairfax County parks, visit the Invasive Management Area (IMA) website. IMA has 60 habitat restoration sites around the county, and the Park Authority is always looking for additional IMA volunteers.

Healthy ecosystems provide better air quality, better water quality, more opportunities for wildlife, and plant diversity. All of that means more opportunities for us to discover new things in our natural world. In Fairfax County, with less than 10% of the land protected in natural areas, it is even more important that our natural areas function as best they can.

English Ivy 2, Mail PostTake time to assess the area around your house. Can you spot English ivy creeping up trees or mailboxes, or did you plant English ivy in your yard? We have suggestions on our website for replacement plants.

Learn more about English ivy in this online field guide and more about invasive plants in this online discussion archive. Our colleagues in King County, Washington, also have an excellent web page with information about English ivy.

Remove English ivy and replant with a mix of native ground covers like ferns, spring beauty, Dutchman’s breeches and trillium. The native plants will be a much more interesting bunch — and not invasive.

This blog was compiled from Park Authority files and edited by Park Authority Ecologist Erin Stockschlaeder.


Caterpillars are Taking off Their Skeletons at Hidden Oaks!

DSC_0268The race is on to see who will become a butterfly or moth first. There are Monarchs, Pipevine Swallowtail, and Tobacco Hornworm caterpillars at Hidden Oaks Nature Center in Annandale.

If you happen to visit at the right time, you may see the Monarchs and Pipevine Swallowtail butterflies being released. The Tobacco Hornworm moths will be kept at the nature center to exhibit as adults.


A natural wonder that typically enjoys great favor with humans, the monarch butterfly makes headlines across North America. As an ambassador insect, or one that represents a genre such as pollinators, these insects often are used to teach about life cycles. Ask any second grader, and she will tell you about the struggles of this tenacious insect that depends on one plant, milkweed, for survival.

As wild milkweed decreases, national organizations and neighborhood nature centers encourage people to plant milkweed varieties to support monarchs and other pollinators. With their widespread popularity, it’s no surprise children delight in observing monarch caterpillars being raised at Hidden Oaks.

monarch cat.-aHidden Oaks has championed monarch butterfly awareness and stewardship since 1996. Monarchs usually do not arrive in the Washington area before July, and this year the first batch arrived at the nature center on July 9. Journey North, an online science education project, records the first spotting of monarch eggs throughout the country. Normally, the D.C. area spots monarch eggs on milkweed after June 20. Recently, the date has been creeping earlier on the calendar, with this year’s mid-April sighting the earliest on record. The earlier arrivals may be due to warmer weather and a reduction of milkweed in wintering habitats.

Monarch 2017-aOften the monarchs winging their way through the D.C. area are the last of four generations produced over a calendar year. The last generation is physiologically different from the previous three. The last generation does not typically have the benefit of fresh milkweed and is generally in a nonproductive mode until after their diapause, or overwintering, in Mexico. The previous three generations, which can mate within a week of emerging from their chrysalids, have a life span of about six weeks. The fourth generation, which can live six to eight months, mates after spending months resting – with millions of other monarchs – in the Transvolcanic Mountain range about 60 miles northwest of Mexico City.

More about monarchs

Pipevine Swallowtail

The pipevine swallowtail begins life as a small, black and red caterpillar. This caterpillar has a strict diet, but is a little more flexible than the monarch. It feeds on many varieties of plants in the Aristolochiaceae family, commonly known as the pipevine family of plants. Aside from being delicious for the caterpillar, these plants also contain a toxin that is harmful to many animals, but the pipevine swallowtail is an exception. The caterpillars use this to their advantage and incorporate the toxin into their body where it becomes a defense against predators.

The toxin stays in the caterpillars’ bodies as they go through metamorphosis and turn into butterflies. When the butterflies are old enough to lay eggs, they choose the pipevine plant as their landing pad. This provides some protection to the eggs and ensures that they have something to eat the moment they hatch. Once they hatch, the young larvae remain together and feed as a group. This defense strategy confuses predators, since a group of caterpillars may look like too big of a bite. Once they are older and their bodies possess warning signs of bright orange spikes, they split from the group and feed alone. Pipevine swallowtails are found from the northeastern United States south and west to New Mexico and Arizona as well as in parts of California.

More about swallowtails

Tobacco Hornworm

Hornworms at WRTobacco Hornworm caterpillars are rather striking in appearance, starting out almost translucent, turning bright aqua blue, and then altering to a bright green with white stripes. The caterpillar also has a red “horn” at the posterior end. The caterpillars grow rapidly, starting at around a half-inch and growing to about three and a-quarter inches.

They grow this big because they voraciously munch on tomato plants, much to the dismay of farmers and gardeners. Although tomatoes are their preferred food, they will eat anything in the family Solanaceae, which includes tobacco, pepper, eggplant, and various ornamentals and weeds. The tobacco hornworms at Hidden Oaks have munched through many of the tomato plants, sometimes in as little as a day. After they’ve eaten their fill, they are ready to become moths.

hornwormsWhile the monarch butterfly hangs from a leaf or branch to create its chrysalis, the tobacco hornworm moth forms a pupal cell below the leaf litter or just under the top layer of soil. It is a dark reddish-brown, with a maxillary loop at the anterior (front) end and a pointed posterior (rear) end. Sometimes these pupae can spend an entire winter underground, with the moth emerging in the spring.

Once they have gone through metamorphosis, the adult moth emerges. The wings are mottled black, brown, and white, and fold under in a triangular manner to help provide camouflage. The hornworm is sometimes called a hummingbird moth due to its tendency to fly nimbly among flowers and hover over them to extract nectar with their proboscis.

More about tobacco hornworm

Visit Hidden Oaks to pick up a free packet of native swamp milkweed seeds to attract butterflies and other pollinators to your backyard or school. Share the joy and wonder with your family and friends by experiencing first-hand the variety of native butterflies, and marvel at the mysteries of caterpillars that scientists have yet to completely unravel.

Author Fiona Davies is the Volunteer Coordinator at Hidden Oaks Nature Center.

Sources: University of Florida, Grow Garden Tomatoes, Butterflies and Moths of North America, and GotScience Magazine.

Treat Yourself by Treating Birds

DSC_7043_edited-2The U.S. Fish and Wildlife Service estimates more than 50 million people in North America feed birds. If you are one of them, you know the rewards. It’s fun!

Bird-4Many Fairfax County residents enjoy luring the color, song and antics of year-round and migrating high-flying inhabitants of the bird world, and a backyard bird feeder is a prime way to do that. Some folks provide seed only during winter with the hope of sustaining resident species, and others opt to feed all year.

By feeding through spring and summer, homeowners witness the joys and tribulations of avian child-rearing. Human parents watch their feathered counterparts fret over when junior will take that first successful flight. In fact, the human interest factor is likely the major benefit of backyard bird feeding.

DSC_3034_edited-2By enticing certain species to their yards, county residents develop an understanding of and appreciation for local birds. A simple scattering of mixed birdseed will attract several species that enjoy feeding on the ground. Families can easily distinguish among the redbirds, doves and the little brown sparrows that descend. Interest grows, and someone makes an effort to learn the names of those Northern cardinals, mourning doves, English sparrows and Carolina wrens.

There are several types of feeders, and they attract different species. Platform feeders encourage mourning doves and blue jays. Keeping the seed off the ground discourages rodents from visiting, but squirrels have a grand time enjoying their fill. Tube feeders have openings that attract perching birds from cardinals to sparrows. The finch feeders with tiny openings accommodate only smaller-billed birds, including house finches and the beautiful goldfinches.

The secret to attracting the birds you want to your yard while discouraging others such as crows or starlings is to provide the preferred seed. Insect eaters gravitate toward protein substitutes such as black oil sunflower seed and suet (beef fat). Suet, available at the meat counter at grocery stores, is less attractive to crows and squirrels when it has no added seed. Cardinals dote on safflower seed, and finches flock to niger-thistle seed in tube feeders.

DSC_2971Homeowners’ number-one complaint about feeding birds is the abundance of squirrels and other rodents attracted by the seeds. Squirrels typically find safflower seed distasteful and may opt to dine elsewhere if they find it mixed with the tempting sunflower seeds. Another option is setting up a separate feeding station of corn and peanuts. Specialty wildlife stores sell squirrel-proof feeders that boast a trap door that shuts out heavier animals, such as crows and squirrels. Sometimes they even work – until the squirrels figure out how to beat the system. Watching squirrels during their trial-and-error can be part of the fun.

A metal case with a locked lid will provide more hours of viewing pleasure than a mesh onion bag. A secured cage on a stable surface will draw the attention of red-bellied, downy, hairy and possibly even pileated woodpeckers plus skittish Carolina chickadees and white-breasted nuthatches. Exclusion feeders or baffles, metal cones over the tops of tube feeders, can help. Squirrels and raccoons will make a quick getaway with anything not firmly attached to a tree or post.

Our videos, Night Thief and Pole Climber, will give you an idea of the skill and determination critters have to get your bird seed.

A quick trip to your local nature center, library or wildlife supply store can provide guidelines for the heights of feeders and distance recommended from trees. To minimize visits from rats and mice, put out only the amount of seed eaten in a day. Spilled seed on the ground not only attracts rodents but can be a health hazard to birds if it molds. Sunflower seed hulls contain a toxin that prevents some plants from sprouting or developing deep roots. You could buy more expensive shelled seed, use a seed tray under the feeder, experiment with plants such as daylilies, tickseed or coneflower under the feeder, rake or vacuum the seed hulls, build a bird feeder patio, or just have a bare spot.

DSC_7802_edited-3Assuring the health of your feathered guests requires regular maintenance. A commonly overlooked component of backyard feeding is a clean, pure water source. Bird mites and other microscopic critters living on birds and dust contaminate water so, if you supply water, clean the bowl frequently to avoid picking up salmonella and other nasty bacteria on your hands. Wash the container and your hands well away from any food preparation or bathroom areas. Throw away seed stored in trashcans from the previous season. Tainted seed can cause illness in your backyard diners. Fresh birdseed is less likely to mold.

Do birdfeeders help or hurt wildlife? Studies show they are merely supplemental food sources. Cornell University has done extensive research in the area, including a 30-year study of backyard birds that has taken advantage of all those bird feeders out there.

Through feeding backyard birds, you bring nature up close to observe the fascinating nuances of our indigenous bird life. You may discover how to differentiate a male from a female woodpecker by noting the amount of red on the head. You might delight in seeing the gradual change of the drab olive goldfinches during non-breeding times to the spectacular bright yellow breeding colors of approaching spring. You may even glimpse a male cardinal’s courtship of feeding his ladylove a seed right at your back window. While you enjoy the natural history lesson, the birds are benefiting from a boost in their diet. With proper care, backyard bird feeding can be a win-win situation, and that is something to crow about.

Author and Naturalist Suzanne Holland is the Visitor Services Manager at Hidden Oaks Nature Center in Annandale, Va.

The Link Between Beavers and Water Quality

Beaver 1When you hear of a new development, usually you think of a new business, house or apartment complex. It might surprise you, if you live next to a park, to learn that new houses are rising all the time near you. They’re houses for wildlife, and they’re often built by beavers.

Beaver 2Beavers don’t know the difference between a nice, ornamental crape myrtle in your yard and a Virginia pine standing on parkland. That’s sometimes a source of disagreement as to the true value of beaver houses. However, a three-year study by U.S. Geological Survey (USGS) Ecologist Dan Kroes shows their value in streams.

The USGS study shows that dams and lodges, as beaver houses are properly called, are important to water quality. Dams trap as much as two feet of sediment that would otherwise go downstream. Sediment in water is what makes streams cloudy or murky. Not only are sediment-filled streams unpleasant to look at, they don’t allow sunlight to play its role in aquatic food webs. If there are lakes downstream, the sediment settles and may eventually fill those lakes. Witness Lake Accotink in Springfield. It was 23 feet deep  when it was constructed in the 1940s, and despite numerous dredging efforts, it was a mere four feet deep by 2018.

Beaver dams and lodges also slow the water tumbling downstream. By extension, they reduce stream bank erosion that undercuts banks and fells trees. They slow the pace of streams, which improves drinking water quality, increases stream life and decreases flooding. It’s development that’s good for the environment.


No Child Left Inside at Hidden Oaks’ Nature Playce

Nature Place_0245Whatever happened to parents saying, “Go outside and play?”

In nature, it’s just as important to know what not to be afraid of as it is to know what to fear. Unfortunately, in our increasingly urban county, some parents have become so fearful of what might be out there that they won’t even let their kids play in the back yard.

That’s where Nature Playce at Hidden Oaks Nature Center comes in. Hidden Oaks Visitor Services Manager Suzanne Holland says the play area is designed for nature-phobic parents as well as for their three- to ten-year-old children.

In speaking with parents, Holland found that many limit their children’s time in nature because they’re worried about everything from insect stings and bird flu to poison ivy and poison oak. Nature Playce addresses those fears through education and a woodland area cleared of many things a parent may find threatening. Since 2008, Hidden Oaks staff has encouraged preschool teachers and other child care professionals to embrace taking children outside for traditionally indoor activities and include unstructured play in their curriculum. There are monthly three-hour workshops for the Institute of Early Learning, a division of Fairfax County Office for Children, that focus on Nature Playce and how to use outdoor play to engage children in both cultural history and nature.Nature Place 3

Off the Beaten Path

Part of Nature Playce’s appeal to children is letting them break some rules. For example, there is no trail to stay on. Children can roam the one-third acre area, pick up stones and roll logs to see what’s underneath. They can hop across stumps known as tree cookies and walk on a log. Touching is a “yes” activity. Kids can even make mud pies.

Before entering Nature Playce, parents are encouraged to visit the nature center for a ten-minute introduction to playing safely outdoors. Children and adults get tips on such things as how to identify a copperhead snake and avoid poison ivy, how to safely handle a worm, and how to figure out which bugs are safe to touch. They also learn how to roll a log and why the log should be replaced.

After the introduction, children are dubbed official “Nature Snoopers” and receive “a key” to the play area – a large, colorful magnifying glass. They are invited to explore with a Nature Snooper’s pail of goodies – digging tools, cups, books and feathers.

Nature Place 4Naturalists keep the play area as safe for young children as possible by clearing out such things as poison ivy. A low, split rail fence surrounding the area provides a sense of security. Once children pass through the gate, they can venture through four areas that present new opportunities for fun and that grow progressively “wilder.” They’ll discover a waterscape surrounded by boulders to climb, supports to make a fort, a dirt pit for digging, hidden dinosaur tracks, fallen trees to balance upon, and stumps and rocks to overturn. Parents can sit back on rustic benches and watch the kids explore or join in the fun.

Nature Place 1Holland says the area is designed to “provide assurances for parents while stimulating a sense of wonder.” Children need an adult to support their exploration, and she says her hope is that “as parents and children become more open to having an adventure, they’ll be more willing to go into their back yards.” Parents can join an email list to learn about other activities and programs at the center.

The typical response from parents who visit Nature Playce? Holland says she often hears, “What a great idea. I used to love to play outside,” or “My friend needs to bring her kids out here with us. She is not as comfortable with bugs as we are.”

Nature Playce Targets Nature Deficit Disorder

Is there such a thing as being too safe with our kids? If it means disconnecting them from nature, the answer is yes. That’s Richard Louv’s argument in his book Last Child in the Woods, the inspiration for Nature Playce at Hidden Oaks Nature Center.

Today’s parents are familiar with Attention Deficit Disorder and No Child Left Behind laws. Nature Playce exists to combat the growing Nature Deficit Disorder among today’s children and support the No Child Left Inside movement.

The Children and Nature Network says researchers have found connecting with nature can:

  • Increase creativity and school achievement
  • Increase focus
  • Reduce stress
  • Increase cooperation
  • Reduce aggression

Nature Place 5Holland says unmasking the outdoors for children fosters an appreciation for nature and environmentalism. By getting kids outside, you plant seeds for the “environmental stewards of the future who will care enough to vote to protect trees, wildlife and other green issues.”

Hidden Oaks will celebrate the 10th anniversary of Nature Playce on September 29, 2018. There will be an open house during an afternoon of activities in Nature Playce and at the nature center.

Nature Playce is on the web at

Author Carol Ochs works in the Park Authority’s Public Information Office.