Biodiversity Task Force's Spring bird walk

by Marshall Jones, May 2007

Bird Walk leader Alan Williams identifies birds by sound and sight. Photo by Paul Farmer.

On Saturday, May 5th, Cory Koral welcomed the Biodiversity Task Force's annual Spring Bird Walk to Jordan River Farm. The cool, overcast day did not deter twenty-four bird enthusiasts, who joined leader Alan Williams, ecologist and data manager from Shenandoah National Park, in a very successful morning of watching migratory and resident birds.

Alan, who has studied birds on their migratory journeys from Panama to the United States, pointed out that a "bird walk" might be better called a "bird stand", since it finding birds involves frequent stops and much time peering at fleeting shapes in the treetops and thickets. A keen ear is also helpful, for many birds are heard much more frequently than they are seen.

	Indigo bunting, top; scarlet tanager, bottom. Photos courtesy USFWS.

The first week of May typically is one of the peak periods for the Spring bird migration. However, the cool temperature that morning meant that the birds would not be as active as on a sunny day, because the insects on which they feed are slower to arouse from their night-time torpor in cooler weather.

Nevertheless, participants were treated to a fine selection of birds. In the trees at the edge of the woods, they saw a prairie warbler and strained to hear its buzzy call. In the field behind them, they watched a brown thrasher and listened to the sweet monotone whistle of the field sparrow, accompanied by the paired warbling phrases of several indigo buntings. The male buntings were proclaiming their ownership of choice nesting areas, both to keep out other males and to bring in females to their hard-won patches of Jordan River Farm real estate.

In the woods, the group found a mixed flock of migrating wood warblers, most likely birds which had stopped to rest and feed in Rappahannock County before moving north to breed. This flock included black-throated greens, parula, and chestnut-sided warblers.

A migrating flock of about eight blue jays also flew overhead, moving from one patch of trees to another in a generally northward direction.

These birds all feed on caterpillars and other insects in the canopy, including the abundant tent caterpillars. The caterpillars are in turn ravenously eating newly emerging leaves before the leaves have had a chance to accumulate the toxins which help protect older leaves from insect attacks. Tent caterpillars have their own defense mechanism, the toxic hairs which cover their bodies, and Alan described how many birds, after seizing one in its beak, will whack it sharply against nearby branches to remove as many of these hairs as possible before swallowing it.

Walkers finally spot the elusive scarlet tanager. Photo by Emery Lazar.

Finally, for those intrepid participants willing to squeeze through an old fence line and dodge the poison ivy, a scarlet tanager put on a marvelous show. For several minutes, he tantalized everyone with his hoarse treetop song and distinctive "chick burr" alarm calls.

At the end of the walk, the group had seen or at least heard twenty-one species of beautiful birds, plus one decidedly ugly electric transmission tower, where the infamous Dominion power line crosses the northern edge of Jordan River Farm.  Cory Koral then gave the group a special bonus – a tour of the off-the-grid, steel kit house he recently built to free himself of dependence on power produced somewhere else.  Although this is only a one-bedroom house, Cory pointed out that the house's four solar collectors and six storage batteries actually would be able to accommodate a family of four.
 
The Task Force thanks Alan Williams for leading another superb walk and providing a fascinating commentary on the ecology of birds seen; Cory Koral, for making his farm such an attractive habitat for birds, and for inviting bird watchers to share in it; and Central Coffee Roasters for providing the coffee that fortified the group on this cool but captivating morning.