Nature Notes – Merrimac Farm April 29, 1012

by Harry Glasgow

On the last Sunday of every month, the Prince William Conservation Alliance sponsors a nature walk at the Merrimac Farm Wildlife Management Area in Nokesville.  This morning, we walked this very beautiful remote property and tallied 38 species. 

Of particular interest were Warblers.  We found an abundance of Prairie Warblers, and what could almost be called a flock of Hooded Warblers along the area’s Cedar Run Trail, which provided the greatest concentration. 

A Louisiana Waterthrush, one of the Hooded Warblers, and the Magnolia provided the best views, while the others were heard rather than seen.  

White-eyed Vireos were very plentiful, as were Red-eyed Vireos, Barred owls, and even a few Wood Thrushes.  It was a beautifully cool and bright morning for a walk deep in the woods. The full list is below the fold and the preliminary bird list for Merrimac Farm is online here.

There is no such thing as a dead tree

Guest post by Harry Glasgow

In the forest, in autumn, an acorn drops from an oak.  Soon, a bushy-tailed squirrel finds it and obeys an ageless urge to bury it to be dug up later during the spare oncoming winter. Soon forgotten by the squirrel, it remains buried through the winter, and begins to germinate the following spring.

In several years, the acorn develops into a sapling, and begins the struggle for survival. It must compete with other trees for its share of sunlight, nutrients from the soil, and water. Its leaves are bigger than those of its parents so that it can devote more energy to absorbing the necessary light and carbon dioxide than the adult trees, thus promoting faster growth.

As it grows, more branches sprout with more leaves, and it is steadily gaining in the struggle for space.  Soon, birds begin to explore the sapling for insects, and for nesting sites. 

Bluebell Festival a Hit!

This year’s annual Bluebell Festival at Merrimac Farm (and my first) on April 15, turned out to be a great experience even though the famous bluebells were past their peak due to the unseasonably warm weather. As such, there was a greater focus on wildlife and history.

Several hundred participants, including many families with children, arrived in a steady stream throughout the day. Once greeters mentioned that Alvin the albino corn snake was available for petting, the children made a direct beeline for his enclosure.

“I got to hold him. He’s cool!” said 7-year-old Jason. Dad nodded in agreement, but Mom wasn’t so enthusiastic.

Stream Stewards – Temporary streams help save the Bay

Jake Hosen, University of Maryland, gave a great talk on streams and what keeps them healthy on Thursday night (4/4), and followed it up Saturday morning with a guided walk through the flood plain of Cedar Run on Merrimac Farm to view the streams there.

Streams that flow year-round are known as perennial streams, while temporary streams have no water flow during some portion of the year.

There are two types of temporary streams. The first are intermittent streams which do not flow year round but are fed by groundwater during some portion of the year. The second type, ephemeral streams, receive water only from rain and never from groundwater so they usually flow less often than intermittent streams.

It turns out that streams are not only lovely to look at, they have many interesting characteristics. Streams are ubiquitous – there are approximately 1.6 million miles of 1st order streams, which are the smallest streams in a river network. Overall, in the continental United States and Hawaii a remarkable 59% of stream length is estimated to be temporary.

The One Stream at a Time Tour

by Terry Reardon

Last Sunday (3/25), the Prince William Conservation Alliance’s first session of the Stream Stewards program kicked off with an eye-opening tour of two badly damaged streams, one in Hylbrook Park and the other half a mile away off Route 1 (view photos here). Both streams are high priority restoration candidates that illustrate the opportunities and challenges for Prince William County to protect local water quality and help save the Chesapeake Bay.

After remarks by County Supervisor Mike May about the challenges the county faces in restoring already damaged water resources and working to prevent future damage, County Environmental Engineer Clay Morris began by pointing out the Hylbrook Park stream’s precarious location in a heavily developed section of Woodbridge.

Morris pointed out several factors that would hinder the restoration of the stream that may not be immediately obvious to the lay conservationist. For example, there is only a narrow strip of ground on either side of the stream in which to work, leaving no space for the necessary easements, or an area for staging the restoration work. Most importantly, there is no room for the engineering of the stream bed to allow it to properly channel the large volume of water that rushes between its banks during a storm.

Bugs are our friends – Red Flat Bark Beetle

While walking along a trail at Leesylvania State Park yesterday, a half-inch long, curiously flat bright red insect caught my eye.  The Red Flat Bark Beetle, Cucujus clavipes, is typically found under the bark of ash and poplar.  Its flat shape allows it to easily move around under bark, and sometimes even into the tunnels of destructive wood borers and bark beetles, which it likes to eat.  This is beneficial, as it helps limit wood borer and bark beetle damage to the tree.

The larvae overwinter from North Carolina to as far north as Alaska.  Scientists have been studying the Red Flat Bark Beetle to determine how the larvae survive such cold winters.  Beetle larvae produce glycerol, an anti-freeze protein, that enables them to survive to temperatures as low as -100C.   The concentration of glycerol in larvae in more southerly climates is less than in larvae in Alaska, so the temperature that they can withstand is different.  Alaskan larvae have a higher concentration of glycerol because they undergo more dehydration than southern larvae.   According to scientists at the University of Alaska’s Institute of Arctic Biology, knowledge of glycerol could be used to create a solution to cool human organs in order to preserve them, to create a non-toxic de-icing solution for aircraft, or a concrete that will set in colder temperatures.  For you ice cream lovers out there, it might even be able to be used as an ingredient that could prevent the crystals that form inside an open carton of ice cream.

What a beneficial insect, and it’s pretty too.

Merrimac Farm Spring Work Day

Spring is here a little early and Prince William Conservation Alliance members kicked it off with another fun and productive volunteer work day at the Merrimac Farm landscape conservation project and the Stone House.

Last Saturday (3/10/2012), volunteers tore down the old fascia boards on the front porch of the house and put up new fascia. New rain gutters were also installed.

In the back in the conservation project, trenches were dug for the corrugated flex pipe that was laid to connect the two rain barrels that were set up; there will be a third rain barrel installed in the coming weeks. The water collected in the rain barrels will be used to water the plantings in the landscape project.

The native plants that were planted last October easily survived the mild winter. Serviceberry, coneflower, wild ginger and columbine are already sending out new green shoots. During the course of the work, a bald eagle was spotted conducting a flyover of the farm.