THE VIRGINIAN-PILOT
Copyright (c) 1996, Landmark Communications, Inc.
DATE: Friday, October 25, 1996 TAG: 9610240156
SECTION: VIRGINIA BEACH BEACON PAGE: 08 EDITION: FINAL
TYPE: COVER STORY
SOURCE: BY MARY REID BARROW, STAFF WRITER
LENGTH: 158 lines
WHEN ECOLOGIST Bryan Watts ventured into the woods at Little Creek Naval Amphibious Base on a recent morning, he found several tiny winter wrens squirming in the nets he had set up a day earlier.
The little brown critters chattered angrily as Watts, director of the Center for Conservation Biology at the College of William and Mary, and student assistant Mike Wilson began untangling wings and claws from the netting.
One-third the size of a Carolina wren, these little fellows were probably migrating from New England and Canada and could have flown as much as 400 miles the night before, Watts explained. The wrens chose to stop at Little Creek to rest and feed before embarking for their eventual destination somewhere in the Gulf states.
Their plans were somewhat delayed this day, however, as Watts stowed the critters unceremoniously in mesh bags until he could check them over and band them. The story would be the same that morning at five other woodland sites around the Navy base.
In this instance, Watts' research is funded by the Legacy Program, a Department of Defense effort that seeks among other initiatives to preserve natural habitats on naval bases. His findings offer ecological advice not only to the military community but to local residents as well.
Little Creek has prime parcels of woods, some of the last coastal green spaces left in Virginia Beach. The Little Creek base also is almost directly across the Chesapeake Bay from the tip of the Eastern Shore. This time of year, millions of migrating birds funnel down the shore, gathering at the tip to make the hazardous Bay crossing.
``And many stop at Little Creek to rest and refuel,'' Watts said. ``They settle down into the patches of woods and forage and rest during the day.''
Most songbirds fly at night and feed during the day. Winds are usually lighter and it's easier to avoid predators in the dark, Watts explained. Soon after dawn, birds begin to drop into Little Creek and start searching for insects and other food.
Since many songbird species, particularly neo-tropical migrants, are declining, Watts' research will help the Navy determine what it needs to do, when possible, to best manage its resources for these tiny critters.
``If land management questions come up,'' Watts said, ``they'll be able to incorporate the migrants into their plans.''
On this recent day, Watts and Wilson would find not only wrens but yellow-rumped warblers, black-throated blue warblers, hermit thrushes, white-throated sparrows, even a blue jay and a towhee in their nets.
Back at a banding table set up near Scout Island on the base, the two would then examine each bird, measure its wings, weigh it on a spring scale, band it and record the information. Watts would release the bird, seemingly none the worse for wear, directly from his hands.
``Sometimes when you release them, they get right down to foraging,'' he said. ``They don't waste much time.''
Watts often can tell how old a bird is by examining the top of its head. The skin is so translucent that he is able to see the opaque bone that covers the cranium. First-year birds generally have only one layer of bone but a second layer begins to form that eventually will cover the cranium by the second year.
``Ninety-five percent of the birds we catch are young of the year,'' he said.
A bird's pink translucent skin also helps Watts learn about the critter's fat reserves. He spreads the feathers on each bird's breast, the spot where birds store fuel for their long migrations. Watts can actually see the yellow fatty deposits beneath the skin well enough to rate the amount from O to 10. Often birds that drop into Little Creek are running on empty - zero.
Watts and Wilson hope to recapture some of the slower migrating birds, like white-throated sparrows, in a day or two before the critters fly off again. After identifying a bird by its band number, they can compare the bird's weight and fat reserves to the earlier record and determine if Little Creek's habitat is providing the necessary food for another long migration leg.
To this same end, Watts and students also conduct other research. They have marked off circular grids in certain wooded areas to conduct surveys by sight to discover what species of birds are where in the forest. Are they on the ground, in the understory or in the tree canopy and how often do they feed in a given time and space?
For example, Watts, who will complete his research this fall, already knows that if the Navy wants to clear more land, it should clear pine trees instead of the deciduous forest. If the Navy wants to replant an area, it should plant deciduous trees.
``We're seeing some striking difference between deciduous forests and pine forests,'' Watts said. ``Two to three more birds use the deciduous forests.''
One reason is trees that lose their leaves in fall allow native plants and shrubs to grow underneath.
Understory trees like dogwood have plenty of berries upon which birds feed and others like wild cherry and red maple attract caterpillars and other insects.
``Most neo-tropical migrants feed on insects,'' Watts said, ``and pine forests don't produce the insects they need. So if they wanted to replant an area, do what's good for the birds.''
Watts, as the conservation biology center director, is involved in several ongoing studies related to birds and habitat. He's studying saw-whet owls on the Eastern Shore and yellow-crowned night heron and American egret nesting areas in Virginia Beach among other research. Watts also spent several years studying migrating songbirds and hawks on the Eastern Shore before working at Little Creek the past two years.
The research is almost as grueling as the birds' migration. On a recent day, Watts and Wilson would make four more rounds of their nets, folding up shop and the nets around 2 p.m. The next day, they would set out from Williamsburg in time to be at Little Creek at 6 a.m. to set the nets before dawn and start all over again.
For two years, Watts has been keeping this schedule several days a week from August to November, netting, examining, banding and releasing the birds that funnel down the Eastern Shore, cross the Chesapeake Bay and look to Little Creek as a haven.
He's hoping that not only the Department of Defense but also the average Virginia Beach homeowner will learn from his research. Back yards along the migration route can serve the same purpose as a big deciduous forest if they have the right species of plants.
``Plant understory vegetation,'' Watts recommends. ``That's what homeowners can do.''
That includes the dogwood and red maple as well as other native trees like holly and persimmon. It also means leaving a wild spot in your yard where plants like greenbriar, wild grapes and even poison ivy can grow and produce succulent berries. Nonnative ornamentals don't attract the insects that so many birds must have, Watts explained.
``If homeowners could just plant native bushes, they would really help these migrants,'' he said. ``The more you have, the more you can help.'' ILLUSTRATION: Staff photos including color cover by CHARLIE MEADS
Ecologist helps the military and local residents understand
important role this area plays in migration of songbirds.
ABOVE: Bryan Watts untangles a white throated sparrow from a net in
a wooded area of Little Creek Naval Amphibious Base.
LEFT: A migrating winter wren hangs in a net before being rescued by
ecologists in the Department of Defense land-management study.
Having been tagged, measured and his data recorded, a black-throated
blue warbler seems to be resting comfortably before his release back
into migration.
Bryan Watts, left, director of the Center for Conservation Biology
at the College of William and Mary, checks out his nets, then works
with student assistant Mike Wilson to record the bird data for the
Department of Defense study.
A blue jay was among the migrating wrens, yellow-rumped warblers,
hermit thrushes, white-throated sparrows and towhee that were netted
for measurement on this day. by CNB