HomeMy WebLinkAboutducks_of_arlington_reservoirRevised 10/23/20
Ducks of Arlington Reservoir
By John Andrews
On a crisp November day the Arlington Res pulses with life. Mallards and Green-winged Teal
rest on the shoreline as graceful Mute Swans glide by. The honks of an incoming flock of
Canada Geese resonates across the water as they glide in and splash down . Further out, an
elegantly-plumaged Hooded Merganser disappears under the choppy waves, only to emerge a
minute later with a tiny silvery fish in its beak. These scenes are played out in a body of water
that brings a spirit of wilderness into a tamed suburban environment.
The Arlington Reservoir is a natural treasure that spans the Arlington/Lexington border. In
conjunction with the Lexington Community Farm that abuts it, it harbors the richest diversity of
birdlife in the area.
Arlington manages the 65 acre central pond for swimming, fishing, and passive recreation. The
mile-long walking trail that runs around the pond is heavily used by walkers, joggers, dog-
walkers, and nature photographers. Despite the heavy human use, the reservoir attracts
migrants in good numbers. Visiting early in the morning before human traffic becomes too
intense offers the most surprises and can result in spotting such unusual visitors as Bald Eagle
and Osprey.
For the moment, let’s concentrate on the waterfowl. You can find ducks and geese at the
Arlington Res at almost any time of year. But it is during the fall migration, October-December,
that the waterfowl diversity peaks. According to eBird, the birding database of the Cornell
Laboratory of Ornithology [1] , some 31 species of waterfowl have been sighted at the
Arlington Res over the past three decades. On any given day, a careful check of the shores and
waves can easily record over 10 different species of ducks and geese.
It’s helpful to divide the waterfowl into three general groups: dabblers, divers, and
Geese/Swans.
The dabblers are predominantly vegetarian feeders who spend their time in shallow water,
sometimes eating floating weeds, sometimes pulling weeds from the bottom and grabbing an
occasional insect or crustacean. They almost never go completely underwater, but tip up with
their tails in the air. The males are often quite colorful while the females tend toward mottled
brownish camouflage. Most dabblers are found in the muddy, shallow northern part of the Res
or on the sandbars in the southwest area.
The divers are ducks that spend time in deeper water and dive down to the bottom searching
for food. The mergansers are fish-eaters but other divers are looking for weeds growing in the
deeper reaches. Divers prefer the deeper waters in the southern half of the Res and almost
never come ashore.
Geese and swans are larger birds who pair for life. They feed on emerging vegetation in grassy
areas and in shallow water. Sexes are similar. They can be found on sand spits or resting in
deeper water. Often they come to the Res during the day just to pass the time before flying
away to other feeding areas. It’s not uncommon to find a flock of over 200 Canada Geese at
the Res.
Table 1 lists the Reservoir waterfowl species in decreasing probability of appearance. If you
make regular visits to the Res, you should be able to see the species above the dashed line
every year. In any given year it takes some good luck to log the species below the dashed line.
Table 1 Waterfowl Species at the Arlington Res
Dabblers Divers Geese and Swans
Mallard
Wood Duck
Green-winged Teal
Black Duck
Blue-winged Teal
Northern Shoveler
American Wigeon
Gadwall
- - - - - - -- - - - - - -
Canvasback
Northern Pintail
Eurasian Wigeon
Hooded Merganser
Bufflehead
Ring-necked Duck
Ruddy Duck
Common Goldeneye
Common Merganser
- - - - - - -- - - - - - -
Lesser Scaup
Redhead
Greater Scaup
White-winged Scoter
Black Scoter
Canada Goose
Mute Swan
- - - - - - -- - - - - - -
Snow Goose
Greater White-
fronted Goose
Cackling Goose
Ross’s Goose
Brant
Conservation Issues
Because the Arlington Reservoir is heavily used, wildlife and people sometimes clash . Off-leash
dogs can be a problem for waterfowl trying to use the shores and sand spits as resting places.
The water management policies adopted by the Town of Arlington impacts the availability of
the mud flats favored by ducks and shorebirds. Hopefully a balance can be maintained that
allows people to enjoy the Res while maintaining its extraordinary value for wildlife.
- - - -
John Andrews is a Lexington resident who has been birding at the Arlington Reservoir for over
40 years.
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