Managing larger properties for birds, butterflies, and people

Photo and article by Plant NOVA Natives

The outdoor space on larger properties in Northern Virginia, whether residential or commercial, is typically divided into formal landscaping close to buildings and natural areas at the periphery. New practices are emerging on how to manage both areas, practices that protect the ecosystem and support the birds and the butterflies while better satisfying human needs.

The natural areas between properties are an important amenity, providing visual barriers and sound buffers while capturing stormwater and reducing flooding. Looking around, it is evident that those natural areas are often being left to take care of themselves. The result is that they are steadily degrading as the native trees are displaced by invasive non-native trees and are directly killed by invasive vines. The shrubs and ground layers are equally damaged by invasives species at those levels. Many of these invasive plants originate from the landscaped areas where they had been planted before people knew to do otherwise. Preserving trees and habitat in both areas requires taking out the invasives and replacing them with native species, of which numerous options are available.

Some other tweaking is also needed to common landscaping practices. To name a few examples, piling mulch against the trunks of trees causes the bark to rot. Blowing the fallen leaves out from under trees destroys the cover where fireflies and many butterflies overwinter. Leaf blowers with two-stroke engines pour pollution into the air and are loud enough to damage workers’ ears. Outdoor lighting can adversely affect birds, insects and plants. Spraying insecticides kills the bees and caterpillars even more than the mosquitoes they are intended to target. Simple solutions are available to mitigate all these problems.

Professional property managers and community managers negotiate the contracts with landscaping companies and can work with them to adjust their services. Details of the various options for both landscaped and natural areas can be found on the Plant NOVA Trees website in a section specifically for professionals. www.plantnovatrees.org/property-managers Please spread the word to the managers of any properties where you live or work.

The Volcano Near Fairfax County

A photograph of Mole Hill as seen along Route 33.

Article and photo by FMN Stephen Tzikas

When I travel to the Society of Amateur Radio Astronomers (SARA) annual conference every summer at the Greenbank Observatory in West Virginia, I drive along Route 33 just past Harrisonburg, VA, the home of James Madison University (JMU). It’s a rural road, but something unusual is found there – a volcano. It’s called Mole Hill, quite inactive today, but nearly 50 million years ago magma thrusted upwards to the surface through cracks in the lithosphere. The tree covered Mole Hill as seen today is made of remnants of the cooled magma column, eroding at a slower pace than the sedimentary rock around it. That resistant rock that supports the peak is a volcanic plug of olivine basalt. This basalt is dark greenish gray to grayish black, medium grained, and moderately porphyritic. Mole Hill is one of the youngest volcanoes on the east coast of North America. Mole Hill has a height of nearly 1,900 feet above sea level. Another extinct volcano, Trimble Knob, is a little closer to the Greenbank Observatory and a little farther from Fairfax County.

Dr. W. Cullen Sherwood of JMU, who passed away in 2016, gave a brief account of Mole Hill and its geology at the following link: https://csmgeo.csm.jmu.edu/geollab/vageol/outreach/fieldtrips/rockingham/molehill.html

His illustration gives the reader an idea of how Mole Hill may have originally appeared.

Mole Hill is mentioned in the Roadside Geology of Virginia book by Keith Frye. The books in the Roadside Geology Series are an excellent way to explore the geology around us when we travel along roads through different states. These books are available through Amazon.com.

 

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.