The 2022 Butterfly Count Results from the Loudoun Wildlife Conservancy

Photo of Crossline Skipper on Teasel by Michael Myers

Loudoun Wildlife Conservancy has coordinated the Annual Loudoun Butterfly count since 1997. The count takes place in early August, which is the peak time for butterflies in our area. They report their data to the North American Butterfly Association (NABA), which tracks butterfly populations.

This year on August 6, a typical warm, humid summer day, 60 volunteers set out to count as many butterflies as they could find in a single day. It was their 26th Annual Butterfly Count, and they tallied 3,756 butterflies of 45 species in an area of about 178 square miles in the northwestern corner of Loudoun County.

When the count day is over, team leaders tabulate their results, which are consolidated into a report submitted to the NABA. NABA collects reports from all over the country and makes them available to researchers.

Anne Ellis, Butterfly Count Coordinator, has written a very informative article, How Does One Count Butterflies?“, in which she describes this year’s count experience and answers the question, “Exactly how does one count butterflies?”

If you would like to know which species have been seen during previous years, you can view butterfly count data and reports A summary report of species count by year can be viewed here

Take a few moments to enjoy the 2022 Butterfly Count video too.

The 2023 count will be on Saturday, August 5. Please join the Loudoun Wildlife Conservancy and count the butterflies!

Keep Our Wooded Areas Beautiful

Article and photo by Plant NOVA Natives/Plant NOVA Trees

If your community owns some wooded common land, or if you yourself own a wooded property, you may have noticed that the woods around here have been slowly changing, and not for the better. They may still look green, but the devil is in the details: much of that “green” is now made up of invasive non-native plants that damage the ecosystem and bring down the trees.

Natural wooded areas are a beautiful and invaluable resource for any landowner or community. Unlike most material assets, they appreciate over time. They capture stormwater and keep our basements from flooding. They provide soundproofing and a visual barrier between properties as well as a place for us to walk and enjoy nature. They block the wind and lower heating costs in the winter. And of course, they are the home to birds and other wondrous beings, who will need our help if their homes are not to completely disappear.

In the past, the woods managed themselves nicely. In present-day Northern Virginia, at least some care is needed to keep the woods from degrading, turning an asset into an increasingly expensive problem. It is wise to make a forest management plan that looks ahead for twenty or twenty-five years. You can do this on your own, or you can call in a consultant to help you evaluate the situation and map out solutions to any problems. Professional assistance is available, as are volunteers from various programs including Tree Stewards, Master Naturalists, and Audubon-at-Home ambassadors.

The two biggest threats to our woods are invasive non-native plants and browsing by deer. In many places, the deer have taken away everything except the mature trees and the invasive plants, not even leaving the seedlings that should be there to become the next generation of trees. Removing the invasives and protecting native plants from deer are the highest priority in most areas.

Some of our attempts to “improve” the woods may have the opposite effect. Woods do not need to be cleaned! The dead leaves and fallen trees are essential components of a healthy ecosystem. (Dumping extra leaves from your lawn damages that ecosystem, though.) Standing dead trees provide perches for birds of prey, nesting sites for songbirds, shelters for mammals, and food for thousands of species of insects. They are also becoming increasingly rare in our human-managed environment. Try to leave them standing, or if they pose a hazard, just cut off the top and leave as much as you can standing.

For information about how to manage your woods, and how to help your community develop a long-term plan, see the Plant NOVA Trees website.

Triassic Rocks of Horsepen Run

Muscovite mica glitter is apparent in a rock sample from Horsepen Run.

Article and photos by FMN Stephen Tzikas

Part of the Horsepen Run watershed is located in the northwestern part of Fairfax County. Horsepen Run eventually drains into the Potomac River. The trail that follows the creek in the watershed is popular with county residents. A part of the creek is also one of the regular sites of biological stream monitoring, a volunteer citizen science program managed by the Northern Virginia Soil and Water Conservation District. What a lot of people don’t know is that Horsepen Run is home to some interesting Triassic Period rocks, formed some 200 to 250 million years ago. A few years ago I participated in a geological field trip excursion as part of a NVCC 1-day 1-credit course that explored the geologic history of Mesozoic Era rift basin across the Manassas, Leesburg, and Haymarket areas. The excursion was specific to the Triassic and Jurassic Periods. Specific items of interest were the weathering of products; direction of transport; sediment structures; igneous rock textures and their cooling history, the rock cycle, and plate tectonics.

One of the sites investigated was the Dulles Access Road East “utility” off-road on the exit ramp for Rt. 28, at Horsepen Run. This site was the central point of a rift valley deep with sediments. Specifically, it was a lake bottom of red sediment. Some shale exists, breaking into sheets and fine grain. The rift was formed when the Earth

Horsepen Run creek at this location is composed of characteristic red rock: TRb Balls Bluff siltstone, both creek bottom and the adjacent 1-2 foot walls.

was pulled apart at the location. The rift valley is the linear shaped lowland between higher hilly and mountainous elevations created by the action of a geologic rift. Such valleys are likely to be filled with sedimentary deposits derived from the rift flanks and the surrounding areas. At this location the rock type contains Upper Triassic Balls Bluff Siltstone baked and thermally altered material. The red sediment at the location is obvious and contrasts with the appearance further upstream. The glitter found in the red rocks at this location are tiny fragments of mica.

In the Triassic Period, this site was tranquil and sediments came to rest. At the Horsepen Run area, bubbles on the surface of the sediment rock indicate a calcareous (calcium based) dissolved appearance where the red rock voids still have some calcium carbonate (scattered white tones on the rocks). Occasional storms brought water from outlying edges to the center and carried some coarser material. A storm deposit from the west could bring calcium carbonate from the Leesburg conglomerate. A storm deposit episode or event could last minutes to hours.

The lacustrine (lake) facies indicated an oxygen rich environment with red color clastic deposits, allowing the oxidation of the iron. This is facies evidence, referencing the look of rock to respect of environment. If there was no oxygen we would have found black shale. Low energy would have been required for the fine grain to come to rest. Fine grains could also be due to a deep environment, but here it was more likely a shallow one of 10-15 feet, where sediments could dry. This area was a cove of low energy closed lake basin water, subject to evaporation effects. Some “circle fossil” burrow tubes also exist in the fine grain clays. Burrowing organisms lived here causing bioturbation. More evidence of the oxygen rich condition is that the taphonomic conditions were not ideal for preservation, as oxygen rich area deaths led to scavenging and organic breakdown. The terraced layers at the site alternated between siltstone and claystone, caused by changes of energy due to rainfall and climate. Higher energy means more shallow depth silt: wave energy takes away clay silt by the beach. If the climate was a little dryer, the lake would shrink, alternating between shallow and deeper cycles. These climatic cycles were tied to the Milankovitch cycles of variations in the Earth’s eccentricity, axial tilt, and precession.

You also might find some of the glittery red rocks in the surrounding area near Horsepen Run. Recently I visited the EatLoco Farmers Market at One Loudoun near Dulles airport. Between the parking lot and the vendor stalls is a strip of ground, part grassy and part flat thin red rock chips, not unlike what is found at the Horsepen Run site.

Fairfax County Park Authority, Dark Skies’ Webpage

Photo/Image: Courtesy of Fairfax County Park Authority

WHAT IS LIGHT POLLUTION?

Light Pollution is defined by the International Dark Sky Association as the inappropriate or excessive use of artificial light which can have serious environmental consequences for humans, wildlife, and our climate. It’s caused by the excessive and inefficient use of artificial light at night.

This webpage provides detailed information on a variety of topics related to light pollution.

A sample of the site’s contents are listed below:
  • LIGHT POLLUTION COMPONENTS
  • EFFECTS OF LIGHT POLLUTION
  • THE IMPORTANCE OF DARK SKY CONSERVATION EFFORTS
  • TIPS:  WHAT YOU CAN DO TO HELP
  • DARK SKY FRIENDLY OUTDOOR LIGHTING PRINCIPLES

Please take some time to browse through this very informative and comprehensive website,

McLean Gears Up for Dark Sky Celebration, November 12th

Photo: Courtesy of Fairfax County Park Authority

Saturday, Nov. 12, 2022
6:30pm – 8:30pm

Lewinsville Historic House
1659 Chain Bridge Road
McLean, Virginia 22101

Register here.

 

Dark skies are the natural state of nature. Over time, humans have increased the amount of light shining into the sky all night long. This excessive light has robbed us of the glimpse of our stars and endangered the natural world around us. We can have dark skies again if we learn to control light pollution with responsible outdoor lighting practices.

The Fairfax County Park Authority is partnering with the McLean Citizens Association, Dark Sky Friends and the Analemma Society to host a celebration of the importance of dark skies.

Come to the historic house in Lewinsville Park on Saturday, Nov. 12, 2022, to learn about the importance of dark skies in your community. The free event will have hands-on activities and educational opportunities about how to protect the night sky. Learn about nighttime wildlife and constellations. Come experience the night with us and enjoy a small campfire and cocoa. The event runs from 6:30 until 8:30 p.m.

There is no cost to the “Dark Sky Celebration” program, and registration is not required but is encouraged. By signing up, we can notify you in case of inclement weather. The rain date is the following day on Sunday, Nov. 13, 2022.

To learn more about the importance of dark skies, visit the Dark Skies webpage.

State of the Birds 2022 in Northern Virginia, Audubon Society of Northern Virginia

Photo: Chimney Swifts, Gen Cvengros, Audubon Photography Awards

Following a 2019 report that we have lost 3 billion birds in 50 years in the United States and Canada, the national State of the Birds Report 2022 (released on October 12, 2022) shows that birds are declining in every habitat except wetlands, where 30+ years of conservation investment have paid off.

To see the national report, visit StateoftheBirds.org.

Here in northern Virginia, we have also lost many birds. Urban and suburban areas pose special threats to birds, including habitat loss, window and other collisions, and the spread of invasive species, including plants, insect pests, and outdoor cats.

In the face of these losses, there are many things we can do to promote bird conservation. ASNV’s Audubon at Home program advises homeowners on replacing invasive plants with natives. In addition, we advise park managers on how to manage parks for breeding birds, especially grasslands and meadows that support declining species such as Eastern Meadowlarks and American Kestrels.

The new State of the Birds report identifies 90 species that have declined more than 50% in the past 50 years. Of those species, five breed in northern Virginia and should be a special focus of conservation efforts here:

  • Chimney Swift – You can help ASNV protect swifts by letting us know if you have breeding swifts or a fall roosting congregation.
  • Wood Thrush and Red-headed Woodpecker – These birds need healthy forests to breed successfully.
  • Prairie Warbler – This is a species that needs overgrown meadows with Eastern red cedars.
  • King Rail – This a secretive wetland bird that often breeds in Occoquan Bay National Wildlife Refuge and occasionally in other wetlands nearby.

In addition to these five, our region supports important populations of migrating birds in spring and fall. These birds use small parks and even backyards while traveling on their perilous journeys, so everything we do to improve our local environment can make a big difference!

Audubon Society of Northern Virginia

A Year in the Life of an Owl, November 2nd

Photo: Courtesy of the Loudoun Wildlife Conservancy

Wednesday, November 2, 2022
7:00 pm

Rust Library
380 Old Waterford Rd NW
Leesburg, VA + Google Map

Click here for more information.

Join Liz Dennison of Secret Garden Birds and Bees to follow the region’s four resident owls from winter through fall. You’ll learn what makes owls instantly recognizable and find a few surprises hidden under all those feathers! You’ll get a peek into their romantic courtships, the challenges of raising young, and the difficult transition from nestling to fledgling. And finally, you will see the quiet time when the young seek out their place in the world and the adults can (almost) relax. Four Owl Ambassadors will help Liz tell the story. You’ll meet Scarlett (Barred Owl), Hodor (Great Horned Owl), Phantom (Barn Owl), and Kvosir (Eastern Screech Owl) in the flesh, learn about each species and a little about their personal lives in captivity. You might even get to take a few selfies! This program is co-sponsored by Loudoun Wildlife Conservancy and the Loudoun County Public Library.

Invite Flying Squirrels to Your Backyard with a Feeding Box, October 23rd

Photo: Fairfax County Park Authority, Flying Squirrel in feeding box

Sunday, Oct. 23, 2022
1:00 PM – 2:00 PM

Hidden Oaks Nature Center
7701 Royce St., Annandale, Virginia

Program fee for two people: $15.00
Extra supply fee: $25.00

Click here for more information and registration details. 

Flying squirrels are just as common as grey squirrels in our area. As they are nocturnal, flying squirrels often glide under our radar. From November through March, they are easy to welcome to backyards with large trees.

Families can learn proven strategies to encourage these amazing native flying squirrels to your treed backyard. A naturalist will show you how to recognize their presence and guide you in assembling a feeding box to take home. Two attendees are permitted per registration (one adult and one child over age 4 or two adults). This is an outdoor program. Please bring your own hammer and Phillips-head screwdriver. A $25 supply cost will be included at check out. The program fee for two people is $15.

“Make Your Own Flying Squirrel Feeding Box” is on Sunday, Oct. 23, 2022, from 1 to 2 p.m. at Hidden Oaks.

Plant NOVA Trees — One Year On

September marks the first anniversary of the launch of Plant NOVA Trees, a regionwide effort by over a hundred local organizations and thousands of individuals to promote native trees and shrubs in Northern Virginia. There is no regional tree planting agency that can do the job for us. Rather, it is up to each individual to look around to see how they can contribute, at home, at work, or on common land. Plant NOVA Trees connects people to the resources they need to do that.

There are many ways to participate. The simplest is to identify every appropriate site and plant young trees or shrubs there now, preferably canopy trees if there is room. They may not look like much the first couple years, but soon they will grow and provide shade and cooling for humans as well as shelter and food for our birds and butterflies. Information on how to choose and plant a native tree or shrub is available on the Plant NOVA Trees website. Fifty volunteers have visited local garden centers to hang thousands of tags on the native trees, making them easy to identify. (The same volunteers have been putting red stickers on all the native plants in those garden centers for several years.)

Each of our local jurisdictions and park services has tree planting plans for public lands. For example, the Prince William Soil and Conservation District has been working with 3rd and 4th graders to plant trees on school grounds. Kudos go especially to Purcellville, which planted 118,100 trees last year on former farmland that is owned by the town.

Members of local communities have also gotten together to plant trees in their common areas and to help residents plant on their own properties. So far, residents have self-reported 7850 trees and shrubs  on the Plant NOVA Trees website form. The Virginia Department of Forestry is collecting these figures as it works to meet its goal of 600,000 planted in Northern Virginia by 2025. This number is intended to help our region meet its obligation to protect the Chesapeake Bay, since runoff from roofs, roads and empty lawns is causing damage downstream, and trees are nature’s tool for capturing water. Those who appreciate our waterways should give careful thought to how they can contain stormwater on their own properties before it rushes off to erode our streams and dump sediment and pollutants into the Bay.

Despite all these efforts, Northern Virginia is gradually losing tree canopy. Multiple factors contribute to tree death. Some are hard to change on a local level, such as the stress on trees from climate change. Others are absolutely within our control, such as poor planting and mulching practices or the sacrifice of trees for more roads, buildings, and park amenities. Each native tree lost is one less home for birds and other wildlife as our local ecosystem suffers its death from a thousand cuts.

Invasive vines (as opposed to the beneficial native vines) pose another important threat to trees, and this has become one of the foci of the Plant NOVA Trees campaign. Volunteers for the new Tree Rescuers program spot trees that are at risk from English Ivy, Asian Wisteria, or other invasive non-native vines and drop off literature with the owners to alert them to the easily-mitigated problem. While they are at it, the volunteers count the trees at risk so we can get a more precise handle on where resources should be concentrated. So far, over two hundred volunteers have alerted 799 residents to 3491 trees at risk in 4.2 square miles of residential properties. In addition, they have counted almost 22,000 trees at risk in 3.3 square miles of non-residential areas. The data collection is too preliminary to make an accurate extrapolation, but it would appear that the total number of trees in need of rescue in Northern Virginia’s 1,300 square miles may be in the millions.

There are numerous opportunities around Northern Virginia to help control these invasive vines by cutting them near the ground. Over 3500 trees have been reported as saved so far. Besides saving the trees on their own properties, volunteers can organize the work on common land within their communities or join the invasives management programs of the various park services, listed on the Plant NOVA Trees “Rescuing Trees” page. Residents and communities can obtain a permit to clip the vines on VDOT property. In general, though, the resources to control invasives on government-owned land and easements will need to come from the governments themselves (and ultimately from the taxpayers.) It is also critical that everyone stop planting invasive plants to begin with, not only the invasive vines but all the other invasive non-native landscaping plants such as Bradford Pears and Burning Bush that escape from our properties into natural areas.

Businesses have been helping with the regional tree campaign in several ways. Local garden centers are promoting native trees and shrubs in honor of Celebrate Native Trees Week (Sept 26-Oct 2). Landscaping companies are increasingly choosing native species,  and a few have started to offer invasive plant removal services. Any company could educate its employees and customers and provide financial support to neighborhoods that need help with their open spaces.

Those businesses that control property can plant and preserve native trees there, which in some places may mean tearing up concrete to make room.

So what can you do to support the native tree campaign? Plant NOVA Trees is essentially an educational organization. The success of this initiative depends on the individual efforts of residents  across the region. So what can you do to support the native tree campaign? Plant NOVA Trees is essentially an educational organization. The success of this initiative depends on the individual efforts of residents across the region. There is no shortage of ideas on how to get involved, whether where you live or work or on a wider scale. Find these ideas on the Plant NOVA Trees website.

Bluebirds at Langley Fork Park Continue to Thrive

Feature photo: Bluebird nestling residents of Box 6 (May 21, 2022). What are they thinking?

Article and photo by FMN Stephen Tzikas

The 2022 Bluebird box monitoring season at Langley Fork Park in McLean was my second year, and first as its trail leader. The trail leader duties came unexpectedly, but it successfully concluded thanks to the existing and new trail monitors who helped me with this success. Although I wrote an article last year on the extraordinarily successful season at Langley Fork Park, in part due to the cicada bounty, I was pleasantly surprised that this year’s Bluebird fledglings approached very close to the number we had last year.

In 2021 we nurtured 63 total protected birds which included 26 Bluebirds. In 2022 we had 57 total protected birds which included 24 Bluebirds. This can be contrasted to the 5 years prior to that in which Langley Fork Park monitoring succeeded with about 40 protected birds per year which included about 5 Bluebirds a year. Since our efforts are on behalf of the Virginia Bluebird Society and the Bluebirds themselves, having about a 5-fold increase in Bluebirds these past couple years was phenomenal.

As trail leader, I had a closer look at the total 7-year record of data at Langley Fork Park in order to determine if any changes in the location of the Bluebird boxes were necessary to increase the effectiveness of the Bluebird program even further at Langley Fork Park. This data is part of the Nest-Watch database administered by Cornell University. I found the record-keeping in the years prior to 2021 to have some gaps, but this did not detract from the large increases recorded for the Bluebirds at the park. Nonetheless, the gaps were an interesting comparison that should not be ignored for a program’s quality control. Monitoring in prior years were not always on a weekly cadence, and it was not certain if preventive maintenance was rigorous. While I could infer final fledgling counts on what was recorded, these numbers could have been a bit higher and a good maintenance regimen could have made a nest box habitat resilient for an immediate welcoming of a new set of Bluebird parents during critical times for egg laying. This is contrasted to a strict weekly check on the birds in 2021 and 2022, and immediate attention to issues of concerns: wasp nests, ants, predators. For Bluebird monitors, I can’t emphasis enough how important these matters are. Bluebird monitoring trails should have an adequate number of team monitors to keep pace and avoid burdens with scheduling for a trail that has too few monitors.

With this analysis I did have enough data to make some conclusions for future planning. In the past 2 years, 3 of the park’s 10 boxes had successful Bluebird nestlings, while in the entire past 7 years, 6 of the 10 boxes were home to successful Bluebird nesting attempts. Considering that Tree Swallows are also a protected bird and the main successful competitor of the Bluebird boxes, our Bluebird attempts are good.   But can we do better? These are decisions for our trail that may help others in their trail decision-making too.

Before the close of the 2022 season, our team suggested that moving boxes 1, 4, 7, 9 might help the Bluebirds, because currently they had some issues with predators and intense competition.

The data showed that boxes 1, 2, 5, and 9 never had Bluebirds.   We also have the opportunity to add an 11th Bluebird box which will be determined at a later date. While boxes 2 and 5 may never have had Bluebirds, they are in good locations and have other active protected birds nesting here. These will not be relocated for now.

  • Box 1 is in a fairly hidden area. By moving it closer to the parking lot it may get more attention by the Bluebirds.  There is some playground equipment here, but on closer inspection it is for adults to exercise who are not likely to interfere with the box.  The location is more bushy, so it may also attract more House Wrens too.
  • Box 4 has had occasions of broken eggs from intense competition.  Moving it from the corner of the field to a more bushy area closer to some benches could improve it.
  • Box 7 may be too close to a tree with snake predators. Moving to a more bushy area a few feet away may help.
  • Box 9 is in a fairly active area with baseball activity, and relocating it closer to Box 8 may help. The advantage of the new location is that it is slightly less active and has more trees, but it is not necessarily a suggested 100 foot separation from Box 8.

The 2023 season will evaluate these adjustments.