Category: In the Field

Eight nests active, but no hatch activity yet. A couple of the boxes are due. Along with my pollen allergy, swallows have arrived in the area: we saw all three common species. Common Yellowthroat (Geothlypis trichas) and Blue-gray Gnatcatcher (Polioptila caerulea) were audible, Paul ID’d a Pine Warbler (Dendroica pinus), and Myra saw a lifer Winter Wren (Troglodytes troglodytes).

This Common Snapping Turtle (Chelydra serpentina) popped an eye out of the water to check me out while I was pulling out my point-and-shoot, then dropped back down below the surface when he’d decided that I wasn’t worth bothering with. The shell is about 10 inches across the long dimension.

There still isn’t very much green in the park, but the birds are getting busy. We have two nests of Hooded Merganser active, and three of Wood Duck. As we were getting our gear ready in the parking lot, a scruffy-looking Red Fox (Vulpes vulpes) scarpered down the blacktop path in the direction of Lockheed Boulevard.

Since the visitors’ center doesn’t open on Sunday mornings until later in the season, we were glad to see the return of the portable outhouse to the grounds.

Spring Beauty (Claytonia virginica) is beginning to scratch its way through the leaf litter. New birds spotted include Eastern Phoebe (Sayornis phoebe), Osprey (Pandion haliaetus), Belted Kingfisher (Ceryle alcyon), and Pied-billed Grebe (Podilymbus podiceps).

Our gang of four nest box monitors got started early again this year, but a Hooded Merganser hen was ahead of us, with 6 eggs already on box #7.

The water had a good crust of ice, but it was easily breakable. A good number of teal and pintail on the ponds of the wetland. Red maples in bud. As we stowed excess wood chips in the shed at the visitors center at the end of the morning, a large flock of grackles blew in, to be snagged by the trees above.

Pleasant weather and I’m off for a hike in Shenandoah National Park. New weather was coming in, so I had clouds and breezy conditions, warmth only when the sun broke through, and even a few sprinkles of rain.

I walked an easy-rated 5-mile loop starting with the Sugarloaf Trail (hike #3, short circuit, in PATC’s Circuit Hikes in Shenandoah National Park). The footing was definitely soft in spots, due to overnight rain. The Sugarloaf Trail descends 700 feet through an impressive tract of mountain laurel (not in bloom at this time of the year, alas).

The trail crosses a braided stream (Piney River, which feeds into the Thornton) that seemed determined to follow the trail bed for a stretch. The circuit then ascends gradually on the Keyser Run Fire Road. Crossing Skyline Drive, you pick up the Appalachian Trail for a climb of Little Hogback. After a dip, a series of short, stiff switchbacks climbs 400 feet to the ridgeline of Hogback Mountain.

Some fine prospects along this stretch.

Off-season so I had the trail completely to myself, with the company of an occasional raven, woodpecker, or flick of juncos (that’s something smaller than a flock). Otherwise, very quiet, with sometimes nothing but the creaking of bare trees in the wind.

I took a quick walk on the first mile and a half of the Cross County Trail, following Difficult Run down to the beach at the Potomac River. The track was quite muddy in a few places, thanks to this weekend’s rain. This section of the trail lies mostly in Great Falls National Park, and is not posted or blazed save for one sign, but the way is easy to find (just follow the run downstream, how hard is that?). Far from a midwinter chill, the air was quite mild and most of the time I didn’t need my gloves. A smattering of Christmas Eve strollers, a pair on horseback. Still, it’s generally a popular spot, and I saw more trash than I like to see.

I got some good information at the public meeting on September 21 on the planned wetland restoration project at Huntley Meadows Park. We heard from Park Manager Kevin Munroe, FCPA staff naturalist Charles Smith, and Park Resource Manager Dave Lawlor.

The central wetland at the Park constitutes the only large, non-tidal wetland in Fairfax County. (Tidal wetlands can be found along the Potomac in places like Dyke Marsh.) A number of factors—siltation from runoff from housing construction in the 80s and 90s, drought, and the migration of the beavers once they had consumed the desirable trees—has meant that the wetland is going through its natural succession to wet meadow on its way to becoming woods. Along the way, the ecology of the wetland has simplified, with the near-disappearance of crayfish (a foundation species in the food web); the dominance of native but aggressive cattails and rice cutgrass; and the loss of standing dead trees (whose presence supports a variety of species). A consultant’s report in 1993 indicated that, to preserve the freshwater marsh more or less as it was then, as an island of diversity in burgeoning suburbia, water level management would be needed, eventually. Eventually is now.

The new dam across Barnyard Run and its accompanying water control structures will raise water levels as much as two feet. The high-water mark will be 33 feet above sea level. In addition, plans (as yet unfunded) call for four pools to be excavated to a depth of three feet (which means a maximum water depth of five feet), which will enhance habitat diversity. Munroe and staff made it clear that water levels on the wetland will follow the healthy natural cycles within the year (drawdowns in summer, recharging in winter) and across years.

There will be downsides, both short- and long-term. Munroe stressed that the racket of chainsaws and bulldozers will be part of the park experience when construction begins after the 2008 breeding season, next July (per plan). There may be some preliminary work and tree removal as early as November. The expectation is that excavated trees and soil remain inside the park, to be used as habitat. Long-term, the state-mandated access road to the dam will link up the trails leading in from the two entrances of the park (South Kings Highway and Lockheed Boulevard). This historical gap was by design, in order to discourage mischief-makers and joy-riders. Munroe has mitigation plans; I rather like his idea of a fence and stile as a barrier to bikes.

It’s a big, disruptive project, and I suppose that it has to be done. $2 million isn’t a lot of money to preserve a really special place in the county. Munroe seems to be on the ball and he’s doing a great job of citizen outreach.

Plans are firming up for a $2 million project to restore the main wetland at Huntley Meadows Park, reports Frederick Kunkle. The scheme calls for a 300-foot wide earthen dam across Barnyard Run, 3 feet high and somewhat downstream of the main observation tower—about where the most prominent beaver dam has been the past few seasons. Revegetating with native species to fight invasives and non-natives like cattails and rice cutgrass is also planned. The site plan will be presented at a public meeting on September 21 (details here).

I think it’s the gravel access road that will be built to the dam that concerns me the most: it could be the most disruptive change. Also, that section of Barnyard Run has seen the most nesting activity for both Wood Ducks and mergansers; I suspect that they and the beavers will move elsewhere. My colleague Paul points out that this patch of land has been under human alteration for hundreds of years (it’s been farmland, it’s been a test bed for ashpalt pavement), so restoring the wetland is the right thing to do. I just hope he’s correct.

I had just a little time yesterday morning, before we scurried off to the theater, to get out for the first International Rock-Flipping Day, so I poked around in the wooded strip between my townhouse cluster and the middle school grounds. As a result, it turned into one of my quasi-periodic Clear the Trash jaunts. I picked up a grocery bag’s worth of rubbish, a serviceable basketball, and (alas) a seventh-grader’s lab book for Understanding Our Environment.

I turned up a couple of candidate rocks, but nothing more than a retiring earthworm, so I fudged a bit and flipped some bits of wood (unwanted leftovers, probably, from some neighbor’s woodpile). I found a couple of what I make to be Gryllus sp., Field Cricket. Borror and White offer this helpful distinction:

The House Cricket, Acheta domesticus (Linn.), is a species introduced from Europe that often enters houses; it differs from field crickets in having the head light-colored with dark crossbands.

It’s time to hang up my waders for the season, although we have one nest still active to be checked in the next week or so. This morning was a day for surprises, not all of them happy.

When I opened one of our newly-placed boxes, which had had an active nest with 12 eggs last month, I found a bird-shaped bowl in the down and wood chips, but no eggs and no shells. My best explanation so far is that the nest has been clean-picked predated over several days by one or more snakes.

As Myra and I worked our way down lower Barnyard Run, we heard our happiest surprise: a Wood Thrush (Hylocichla mustelina) singing full-voiced in the woods.

New Box 67, which had seen some dumping activity (our last count for the box was 22 eggs), hatched out all but three. But unfortunately, the nest in Box 77 was a near-complete failure, with numerous half-hatched chicks. Unlucky Myra had to clean that one out.

But the big surprise was the abrupt drop in water level along lower Barnyard Run. The dry conditions in the main wetland we expected: at this time of year the mud flats are giving over to grasses. But we expected the substantial beaver dam across the run to be holding back much more water than this. (The green vegetation running horizontally in this image marks the top of the dam.)

Box 60 is usually sitting in about two feet of water (you can see the rust marks on the support pole), but at the moment it’s high and dry. Well, mucky, at least.

The dry conditions made for good viewing of snapping turtles. We found three of the these critters, half-covered in mud, as we walked back. Ours is the Common Snapping Turtle (Chelydra serpentina), ranging from Nova Scotia to the Rio Grande, according to Roger Conant and Joseph T. Collins’s Peterson field guide. They describe the family Chelydridae as “Large freshwater turtles with short tempers and long tails…”

There is a spiffy new sign at the park entrance designating Huntley Meadows Park as a stop on the Virginia Birding and Wildlife Trail. In the capsule description of the site, the designation of Wild Turkey as a year-round resident may be a little optimistic.

The mergansers appear to be done with nesting for the season; birders on the boardwalk spied a hen with seven merglets feeding on the main pond. The Wood Ducks, on the other hand, are still hard at work slow-cooking their eggs. We have five active nests, including (unfortunately) a dump nest with 22 eggs in it.

Aloft, we saw a mini-kettle of three Red-shouldered Hawks picking up altitude. We heard or saw a couple of heron species, gnatchatchers, cuckoos, flycatchers, and vireos, but generally didn’t pause to take closer looks. On the walk back through the woods, Myra and I paused over a perplexing male tanager (most likely a Scarlet), along with a female; the male showed lots of streaky orange.

There are noticeably fewer Canada Geese (Branta canadensis) in the main wetland this year, so perhaps whatever control measures are in force are being effective.