Monthly Archives: March 2013

Hidden Oaks Says Farewell To Darling The Eastern Rat Snake

Darling, an eastern rat snake, swallows a mouse.

Darling, an eastern rat snake, swallows a mouse.

His nickname among some of the staff was Darling. An odd name, perhaps, for a snake, but it did reflect a kind of fondness for him.

We don’t give our exhibit animals actual names because they aren’t pets. We’re naturalists, not purveyors of anthropomorphism. We don’t want to bestow human qualities on exhibit animals because our job is to interpret nature, not humanize it.

But after 20 years with an animal, some kind of relationship forms. And so we noted on March 6, 2013, the passing of the eastern rat snake that spent the past two decades at Hidden Oaks Nature Center in Annandale.

Hidden Oaks Assistant Manager Suzanne Holland tells the story:

We were given the snake in 1993 while it was still an egg along with a few others after a homeowner found a clutch in his mulch pile. Rarely do reptile eggs that are moved survive, for unlike bird eggs, the yolk is unstable in these eggs. But he made it. During the snake’s first year of life, he sported the blotchy gray and black pattern of a juvenile eastern rat snake. These snakes are notoriously aggressive as juveniles, and he bit the animal care staff at every opportunity. Being non-venomous and small, he left only pinprick punctures, and he was not a danger to anyone. As he matured, he got used to being handled and thrived as an exhibit animal. He was often used in school programs and for outreach. His laminated skin, six feet long and shed more than three years ago, is an awe-inspiring sight. Students and parents alike are stunned to learn that he was closer to seven feet long. Since snakes don’t stretch out the way mammals like to, his true size was often underestimated.

If you’ve been to Hidden Oaks sometime over the past 20 years, you’ve probably seen the snake. Although he will be missed, he also will be replaced. Hidden Oaks will remember him only with a photo, one that Holland calls “his glamour shot,” as the eastern rat snake finished a meal of mouse.

Author David Ochs is the Manager of Stewardship Communications for the Resource Management Division of the Fairfax County Park Authority.

Construction Begins On The Huntley Meadows Wetlands Restoration Project

UPDATE: July 17, 2013 

It really hasn’t been so bad, those bulldozers and big yellow machines out in the wetlands. There’s still a lot for you to see. There’s still a lot to do, but the potential rewards are big.The remodeling of the Huntley Meadows wetlands continues this summer.  There’s a major step in the project coming soon.  Construction of the berm in the wetlands is expected to begin in late July or early August. The earthen and vinyl sheet piling berm will allow park staff to raise the water levels in the wetland approximately two feet. That will reclaim water depth that has been lost to silt. The silt comes from erosion and construction associated with upstream suburban development.

The berm is part of a restoration of the park’s central wetland, a restoration that has brought construction equipment to the area. That equipment will be visible in the park’s natural areas for a few more months, however the reconstruction means that in the long term the park will continue to have a functioning, healthy and diverse wetland capable of supporting locally rare plants and animals. In short, you’ll see more cool stuff.

The berm will work hand-in-hand with a water control structure comprised of pipes and slide gates. Staff can use those gates to raise and lower water levels as the seasons pass. The fluctuating water levels will help maintain a healthy wetland for decades and will return biodiversity to Huntley Meadow’s wetlands.

This part of the project was planned for mid-summer to limit the pestering of animals during their reproductive seasons. That keeps the babies safe. In addition, staff and volunteers have removed hundreds of reptiles, amphibians and native plants from areas where digging will take place and shuttled them to other, safer spots in the park.

We expect the water control structure to be completed by September. The project as a whole is on track for completion in November or December. Some cleanup tasks may last until March 2014.

There will be temporary trail closures in parts of the park until the project’s completion. The hike-bike trail off the South Kings Highway entrance is closed. However, the boardwalk and the observation tower are open, so come on out to Huntley Meadows park and watch the changes as the wetlands gets healthier over the coming months.

Got questions? A lot of answers are on the Wetland Restoration Project web page.  Or, give the park a call at 703-768-2525 and speak with Kevin Munroe or Kathleen Lowe.

MARCH 20, 2013

This is going to be great when it’s done, and well worth the wait.

A project has begun to restore the central wetland at Huntley Meadows Park.

A project has begun to restore the central wetland at Huntley Meadows Park.

To be honest, you might be surprised when you see a bulldozer sitting in the Huntley Meadows wetlands. Park staff understands, yet we know there is a rewarding and bigger surprise in the near future. You’re going to see a renewed and healthy wetland with a wider variety of wildlife. Consider the remodeling of a room or front yard. It’s a shock and can be distressing during the process, but the end results make it worthwhile.

That’s what we have in Huntley Meadows Park. There’s a problem, and we’re going to fix it so that the area retains its healthy wetland. We’ve got to go through some discomfort to get to those rewarding results.

Over the past couple of decades, silt and debris have been slowly, steadily filling the central wetland at Huntley Meadows Park. Some of that is natural, and some of it is suburban living. If we let this combination of natural and suburban run-off have its way, pretty soon the wetland will become woodland or meadow. Normally that would be okay, and the Park Authority’s naturalists would be all in favor of letting the park evolve into a forest or grassland. However, there’s another issue.

Huntley Meadows Park has the largest non-tidal wetland in Northern Virginia. There’s nothing else like it in Fairfax County, and it’s incredibly valuable as a wetland to wildlife, to water quality and to visiting county residents, including students, scientists and nature-lovers. So after more than 20 years of tracking the changes, wide-ranging discussions about ethics, beliefs, goals, missions, values and options, and more than 60 meetings, the Park Authority Board considered all comments and decided to restore the wetlands to the condition of its prime years in the 1970s and 1980s.

A healthy hemi-marsh provides habitat for a diverse variety of wildlife.

A healthy hemi-marsh provides habitat for a diverse variety of wildlife.

That’s where the bulldozer comes in. It’s going to take heavy equipment to get the job done. We’re going to do several things that will bring excellent results to the wetland. First, our construction team, supervised by park staff and environmental engineers, will get their beaver on and construct a berm that will hold back water. They’ll install pipes as part of a water control structure that will rest out of sight under water and be used to manage the water levels. Lastly, they’ll provide numerous brush shelters and logs as habitat for wildlife and create five deeper pools. As a result, the wetland will spread into parts of the surrounding forest, and hemi-marsh plant communities will be managed by changing water levels as needed and by varying the water depths. The end result will be diverse year-round wildlife habitat.

A water control system will allow park staff to maintain a consistent water depth.

A water control system will allow park staff to maintain the seasonally fluctuating water levels of a healthy hemi-marsh.

And one more result. Fairfax County residents will get to see the Huntley Meadows wetland return to the regionally significant area that was one of the most productive and diverse non-tidal wetlands in the mid-Atlantic area. It will hopefully again be an attractive home for species that are rare in this region; species such as American Bittern, Least Bittern, Yellow-crowned Night Heron, King Rail, Pied-billed Grebe, Common Moorhen and a long list of reptiles and amphibians.

A healthy hemi-marsh is perfect habitat or the King Rail and other waterfowl.

A healthy hemi-marsh is perfect habitat or the King Rail and other species of waterfowl.

If you’ve only seen the Huntley Meadows wetland of the past decade, you’re in for a surprise. Once it returns to its hemi-marsh, or emergent marsh, condition there will be more water and more wildlife in the wetland. We think you’ll like it a lot, and it will create unique and exemplary education opportunities.

We’re taking these steps and managing the wetland to ensure that Huntley Meadows Park continues to host a functioning, healthy and diverse wetland that will be home to locally rare plants and animals on a consistent, long-term basis.

Construction starts in April, and the project is scheduled for completion in December. Although the visitor center, surrounding trails, boardwalk and observation tower will all remain open, the Hike-Bike Trail (off South Kings Hwy) will be closed for months at a time. This three million dollar project is funded by park bonds and grants.

Got questions? A lot of answers are on the Wetland Restoration Project web page.  Or, give the park a call at 703-768-2525 and speak with Kevin Munroe or Kathleen Lowe.

Written by Dave Ochs, manager, Stewardship Communications, Resource Management Division

Natural Materials Used to Slow Stream Bank Erosion at Huntley Meadows

Fallen logs are used to create a stream blockage to slow the flow of water and prevent stream bank erosion.

Fallen logs are used to create a stream blockage to slow the flow of water and prevent stream bank erosion.

Grown women and men acting like beavers. There are some terrific outdoor tasks in the Park Authority when things have to get done.

East Barnyard Run is the stream that provides the lifeline of water to the Huntley Meadows wetland that is totally dependent on rainfall.  The stream drains about one square mile of suburbia, an area that includes significant acreage of impervious surfaces such as streets and parking lots.  So while bringing the wetland its liquid nourishment, the stream also delivers silt, nutrients and pollution that haven’t been filtered through nature’s normal processes. That creates a constant threat to the wetland ecosystem and all of the animals that call the wetland their home.   

Park Authority staff has been doing a lot to protect the wetland from further damage. There’s been a stream restoration project along one tributary of East Barnyard Run, and there have been planting projects along the run’s two main tributaries over the past several years. The goal of these projects is to stabilize the stream banks to reduce erosion and the resulting silt deposits in the wetland.  

This brings us to our crew of beavers. Their job was to help stabilize East Barnyard Run and reduce the silt and pollution flowing into the wetland. They created a natural material blockage, which is the fancy, formal way of saying they took what nature made and used it to slow the flow of the water. Asad Rouhi of the Northern Virginia Soil and Water Conservation District obtained a $3,000 U.S. Fish and Wildlife grant to build the blockages that would slow the water flow, reduce the amount of silt moving downstream, increase deposition upstream of the wetland and reduce erosion.  Rouhi, Fairfax County Park Authority staff and park volunteers created four blockages using trees that had been toppled in recent storms. Large sections of tree trunks and large branches were systematically laid into the stream.  Logs were then laid downstream of the blockage to protect the stream bed from erosion during storm events.  A tractor helped move and lower the logs into the stream, however many of the heavy and cumbersome logs had to be moved by hand once they were in the stream.  Cable and duck bill anchors driven into the stream banks and bed secured the blockages.

A tractor moves heavy logs into place.

A tractor moves heavy logs into place.

The team moves heavy logs into place by hand.

The team places logs in the stream by hand.

In order to determine the effectiveness of the blockages, longitudinal profiles of the stream in the vicinity around the blockages were recorded and cross sections of the stream were taken above and below each blockage.  Data will be collected from these areas in coming years and compared to previous years.    

Although the blockages seem like a great fix for any stream, Rouhi warns “these BMP’s (best management practices) do not apply to any location.  The location needs to be selected carefully.  We hope that long term monitoring of our project will help us come up with detailed information regarding the site selection, design specifications and intervals where these structures are located from each other.”

Park Authority staff members Jim Dewing and Dave Lawlor lash logs together.

Park Authority staff members Jim Dewing and Dave Lawlor lash logs together.

Huntley Meadows Park is an oasis in the middle of an urban and suburban conglomerate.  The Fairfax County Park Authority owns and operates the Alexandria park, which has a wonderful mix of natural resource communities including forests, meadows and wetlands.  The 40-acre central wetland is the largest freshwater wetland in the region and is the heart of the park.  A 0.6 mile boardwalk traverses the wetland and allows people to get close to the wetland and its inhabitants, including dozens of species of birds, frogs, turtles, snakes and mammals.  

Author Dave Lawlor is the resource manager at Huntley Meadows Park.

Learn about the upcoming wetland restoration project, a large-scale effort to improve biodiversity in the park’s central wetland, here.

Warming Up To Winter Wildlife

If you’re like me, by March the spring jitters have well and truly set in. Balmy teases of April weather spark bouts of cabin fever. The drip of snowmelt, the lengthening of days and, to a nuanced eye, the presence of egg masses in our region’s vernal pools all herald the arrival of warm weather, regardless of what the groundhog sees.As of this morning, however, there is still snow on the ground. My car thermometer read a frosty 36 degrees  at 8 a.m. Major League Baseball teams are playing spring training games, but Old Man Winter is still around for two more weeks.

Instead of holing up next to the fireplace with a thermos, pining for that day you can spring your clock forward one hour, my suggestion is to get outside! Winter presents fantastic opportunities to observe wildlife, you just have to know where and how to look for it.

At Riverbend Park, migratory ducks make this relatively calm section of the Potomac River their home during the winter months. Hundreds of ring-necked ducks, common mergansers, coots, buffleheads, redheads and many other species can be found dabbling and diving in the open water right in front of our visitor center. These ducks will be gone by April, so there’s only a narrow window to catch sight of our friends from up north. A pair of binoculars is an important tool for winter wildlife enthusiasts and not just for spotting waterfowl. The absence of foliage makes viewing from afar a rewarding pursuit. A long hard look at the sycamores and silver maples on river-dividing Watkins Island may yield a glimpse of the fox squirrel, a large tree squirrel more common in the Western reaches of the state than here in the Piedmont.

 

Deer leave hoof prints in the snow.

Deer leave hoof prints in the snow.

 

While some of Riverbend’s warm-weather birds take to the tropics for the winter, others stay year round. Winter can prove to be the best time to view some real dazzling plumage against an otherwise stark background. The reds, yellows, blues, and gold of resident woodpeckers, cardinals, jays, and bluebirds create a vibrant, dynamic palette in and around the bird feeders on the visitor center patio. Woodpeckers like the yellow-bellied sapsucker and finches like the Pine Siskin are some of the rarer species seen by Riverbend naturalists this time of year.

A walk through the woods after a snowfall can also provide clues as to which wintering mammals are active this time of year. Along the flood-plain, footprints in the snow-flecked ice reveal the presence of a pair of otters. Somewhere along the riverbank, their den, a maze of tunnels burrowed into the hillside, will soon house baby pups. For now, the path of the footprints suggest the otters have been popping in and out of air holes cut into the ice; perhaps evidence of playful courting before the female accepts the male as her mate.

Winter gets an unfair rap as a period of lifelessness, sandwiched in between the colorful transformation of autumn and the fresh energy of spring. Venture out to Riverbend, or any other FCPA park and you will become instantly aware of winter’s dynamism and beauty.  The faint quacking of ducks, the echo of pileated woodpeckers drilling for insects and faded hoof prints in fresh snow are subtle reminders that nature can brave the cold better than we can.

Written by Ethan Kuhnhenn, park/recreation specialist, Riverbend Park

A Wonder of Winter, A Harbinger of Spring

A marvel of nature roams the woods, usually silent but for a raucous spring display. Wood frogs, Rana sylvatica, which spent the winter frozen under leaves, have started their annual concert tour of Fairfax County Park Authority forests.

Wood frogs are the only frogs that can live north of the Arctic Circle. They can withstand more than half of their body water freezing without damaging their cells because urea accumulates in their tissues and glucose forms in their livers. This is natural antifreeze that also enables the frog’s heart to cease beating and the lungs to stop breathing. The wood frogs, buried under woodland leaves instead of overwintering on muddy pond bottoms like most other frogs, can thaw and refreeze throughout the winter without harm.

Last month, males began racing to their local hangouts — ponds and vernal pools — emitting a noisy, bizarre call that resembles a laughing cartoon duck to entice the females to join them. Wood frogs are not the first amphibians you’ll hear heralding spring in our area. That honor goes to the smaller spring peeper. However, wood frogs, brown with a black eye mask and about three inches in length, are more easily seen and heard.

Wood frogs' camouflage help them blend into their surroundings.

Wood frogs’ camouflage help them blend into their surroundings.

Wood frogs commonly choose vernal pools as a breeding area because these temporary bodies of water do not host fish and turtles, which are natural predators of the frog eggs and tadpoles. At Hidden Oaks Nature Center  is a pond that is purposely kept free of fish and bullfrogs to support breeding amphibians. Each year we welcome wood frogs, followed by American toads and then spotted salamanders, to breed.

Wood frogs visit the pond to seek out a mate.

Wood frogs visit the pond to seek out a mate.

Even with a suitable site, there are difficulties finding love in the pond. During the breeding frenzy, males may mistake a male for a female or may drown the female, especially problematic for the first females to arrive on the scene. Males emit a loud croak to warn off the advances of other confused males. When the females – the silent sex – arrive, the males clasp them with their forearms in an embrace called “amplexus”. The smaller male holds onto the female until she deposits her eggs (over 1,000 of them), which usually attach to submerged plants or other egg masses.

Female wood frogs can lay over 1,000 eggs.

Female wood frogs can lay over 1,000 eggs.

After just a couple of days, breeding is complete and the parent frogs return to the forest to hunt for insects, worms and arachnids. Tucked back into the forest floor, the adults ignore their offspring and leave behind standing pools soon to be filled with hundreds of tadpoles.

Meanwhile, the egg masses develop algae which provide more oxygen for the young. The eggs in the center of the mass, warmed by the other eggs, develop faster. The warmer the water gets, the speedier the development. Within weeks, the tadpoles wriggle out of their jelly-like egg masses and develop rapidly, growing their back legs first. They scrape algae and decaying plants with a beak-like mouth. As they mature, they are omnivorous and will eat other amphibian eggs and larvae, including other wood frog larvae. Overcrowding and low temperatures can be deadly at this stage, and many tadpoles become meals for another frog, a turtle, a salamander, beetles, leeches or even an owl. Ever full of surprises, the wood frog tadpoles actually seem to recognize siblings and congregate with them. Nevertheless, the sisters and brothers are together for only a few weeks.

By June, the froglets leave the pond, unaware that they’re joining their parents in the nearby woods. About one-fifth scatter, unfortunately finding their way onto roads and, without the important skill set developed in the video game Frogger, they get squished, providing food for birds, raccoons and opossums. By the time they settle into their homes in the woods, they are virtually indistinguishable from the leaf litter. They will spend the summer finding food and trying to avoid snakes, raccoons, skunks, coyotes, foxes and birds. Wood frogs in turn hunt for snails, worms, beetles, spiders, slugs and other arthropods. They are adept hunters that can ambush their prey. Staying silent until the end of winter, wood frogs’ cacophonous duck-like chatter will again pierce the March air next year.

You’ll find wood frogs from the southern Appalachians into the boreal forests of Canada and Alaska. In late February and into March, you can see them closer to home in our own park woods and waters.

Meet some of our area’s native amphibians and maybe catch a glimpse of American toad courtship at Hidden Oaks Nature Center  as well at the county’s salute to Earth Day and Arbor Day, the April 27, 2013 Springfest at the Workhouse Arts Center in Lorton from 10 a.m. – 4 p.m.

Author Suzanne Holland is the assistant manager at Hidden Oaks Nature Center

Riverbend Park’s Bluebell Watch Has Begun

FINAL UPDATE: April 10, 2013

We've finally reached the peak time to view the Virginia bluebells at Riverbend Park.

We’ve finally reached the peak time to view the Virginia bluebells at Riverbend Park.

With the blast of warm weather this week the Virginia bluebells are really blooming. For the next 10 days or so the bluebells will put on a beautiful display. In places along the river trail you are virtually surrounded by them. Don’t wait. Now is the time to come out and witness this spectacular display, because by May they will virtually disappear until next spring.

The Virginia bluebells are in full bloom.

The Virginia bluebells are in full bloom.

Don’t forget to join us at Riverbend Park this Saturday, April 13 from 10 a.m. until 2 p.m. as we celebrate the bluebells at our first annual Bluebells at the Bend Festival. The event costs just  $5 person and features live music, wildflower walks, live animals, face painting, wagon rides, and other family fun activities. For more information, call Riverbend Park at 703-759-9018.

Come enjoy the trails lined with Virginia bluebells.

Come enjoy the trails lined with Virginia bluebells.

UPDATE: April 2, 2013

Virginia bluebells are beginning to carpet the floodplain.

Virginia bluebells are beginning to carpet the floodplain.

The bluebells seen carpeting the floodplain on April Fools Day were no hoax. Despite late March cold and snow the hardy plants are continuing to grow and take over the forest floor. The dark leaves have now taken on their familiar succulent green color and the deep purple flower buds are clustering.

Deep purple buds are beginning to flower.

Deep purple buds are beginning to flower.

The coming weeks will offer visitors one of nature’s finest floral displays. Spring beauties, cut-leaved toothworts, sessile trilliums, and a host of other beautiful wildflowers will mix in and add texture to the lavender bluebell palette.

Don’t forget to join us at Riverbend Park on April 13 from 10 a.m. until 2 p.m. as we celebrate the bluebells at our first annual Bluebells at the Bend Festival. The event costs just $5 per person and features live music, wildflower walks, live animals, face painting, wagon rides, and other family fun activities. For more information, call Riverbend Park at 703-759-9018.

UPDATE: March 18, 2013

Last year the bluebells peaked in March with early warm and dry conditions. This year the bluebells are on their more “typical” schedule and should peak between April 5 through 15. Usually a good rule to follow is get your taxes done a little early and then come out and enjoy the bluebells.

Virginia bluebells are beginning to spread across the floodplain.

Virginia bluebells are beginning to spread across the floodplain at Riverbend Park.

If you can’t make it out during that time, do not be discouraged. There will still be plenty of wildflowers in bloom from the end of March through April. Also, because of the park’s topography not all bloom at once, so you will always find patches of blooming plants in the spring.

Flower buds are beginning to appear.

Flower buds are beginning to appear.

Once blooming is over and the plants develop seeds, they rely on some busy insects to help plant more. Myrmecochory, from the Greek myrmeco “ants” and chory “dispersal,” is seed dispersal by ants. This ecologically significant ant-plant relationship is worldwide and beneficial to both.

The plants produce seeds that have a fatty rich substance attached to them called eliasomes. Worker ants collect the seeds and take them back to their colonies where the eliasome is removed and fed to growing larvae. Once the eliasome is removed the ants either discard the remaining seed underground or they eject them from the colony in nearby soil. This act accomplishes two things. Seeds are deposited in more favorable locations for growing and they are spread, ultimately adding more plants to the population of wildflowers.  So when you visit Riverbend Park to see the bluebells, stop and give thanks to the marching ants at your feet.

UPDATE: March 8, 2013

March has arrived with a mix of warm, cold, wind, rain, and, yes, a little snow. Despite the ever changing weather, the Virginia bluebells continue to push through the soil. Leaves are beginning to change from deep purple to hints of delicate green as chlorophyll is formed from longer days.

The purplish leaves of Virginia bluebells are turning green.

The purplish leaves of Virginia bluebells are turning green.

Bluebells, along with many other spring wildflowers including spring beauties and cut-leaved toothwort, are called spring ephemerals. They bloom early, and then by May all that is left are withering leaves and seeds. Come mid-May, bluebells pull a vanishing act leaving no visible trace of their existence. All of these hardy wildflowers take advantage of the sunlight reaching the forest floor before the towering trees grow their leaves. In March, more than 50% of the available sunlight reaches the forest floor. By mid-April this drops to 30%, and then by May only 10% is reaching the ground.  

Check out next week’s update for a prediction of when the bluebells will peak! Also, learn about some amazing insects that help plant more wildflowers.

Don’t forget to join us at Riverbend Park on April 13 from 10 a.m. until 2 p.m. as we celebrate the bluebells at our first annual Bluebells at the Bend Festival. The event costs just  $5 person and features live music, wildflower walks, live animals, face painting, wagon rides, and other family fun activities.

March 4, 2013
It is the beginning of March with snow in the forecast but there are signs of spring everywhere. Tree buds are swelling, birds are in motion, singing as they go, and the Virginia bluebells (Mertensia Virginica) are poking their leaves through the sandy floodplain soil. Virginia bluebells, also called Virginia Cowslip, Tree Lungwort, Roanoke-bells, Mertens, and Oysterleaf put on a dazzling display at Riverbend Park from late March to mid-April. These flowering plants burst with intense purplish blue flowers that literally carpet the forest floor next to the river.

Virginia bluebells poke through the sandy soil.

Virginia bluebells poke through the sandy soil.

Bluebells line the trail at Riverbend Park.

Bluebells line the trail at Riverbend Park.

The scientific name honors German botanist Franz Karl Mertens (1764-1831). The species name refers to Virginia, where the plant was first identified. Thomas Jefferson grew Virginia bluebells at Monticello which inspired the garden writers of the 18th century to call them “Jefferson’s blue funnel flowers.”  

Virginia bluebells are native wildflowers that are beneficial to early pollinating insects including bumblebees, honeybees, and butterflies.  Check back regularly to see the progress of the bluebells as they prepare for their annual spring show.

Virginia Bluebells

Join us at Riverbend Park on April 13 from 10 a.m. until 2 p.m. as we celebrate the bluebells at our first annual Bluebells at the Bend Festival. The event costs just  $5 person and features live music, wildflower walks, live animals, face painting, wagon rides, and other family fun activities. For more information, call Riverbend Park at 703-759-9018.

Written by John Callow, assistant manager, Riverbend Park