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Andrew Joachim Involved His Biology Students in Research Outside of School
Webpage by Clifford Lamere July 30, 2013
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A GATHERING OF GEESE AND GULLS; STUDENTS TRACK MOVEMENTS OF WATERFOWL WHILE THE DAYS FLY BY
Robert Whitaker, Staff writer for the Times Union, Albany, NY
Section: LIVING, Page: C1
Date: Tuesday, March 5, 1991
All afternoon, Union College biology professor Carl George and a handful of his students had counted the ducks, gulls, and other birds along the Mohawk River from Rexford to Cohoes, leapfrogging in teams of two from one stretch of the river to the next. Now dusk was falling on this chilly day, day, a full moon rising gloriously over the ice-covered Tomhannock Reservoir.
Ice-covered, that is, except for a sliver of open water a mile or so from the north shore. This is where many of the gulls, ducks and Canada geese would come to spend the winter night. "One of the most spectacular events in the whole region is the gathering of the geese," said George, 60, his eye pressed to a sighting scope. "You'll see skeins of geese that have 500 or even 1,000 birds, and you'll see one skein over here, and then another over there, all coming in to the reservoir."
Added one of his students, John Torgan: "They sound like a train coming in."
George and his students are studying the eating and daily migratory patterns of the estimated 5,000 to 10,000 gulls and waterfowl that populate the lower Mohawk River during the winter. They also are charting how this census surges during the fall migration, and drops in the spring when the birds will fly away to far-off nesting areas.
To help complete this picture of the daily wintertime habits of Capital District waterfowl, Andrew Joachim and his biology students at Bethlehem Central High School have been observing the migratory and eating habits of geese and ducks that overnight at Vly Creek (also known as Bethlehem District 1 Reservoir), Alcove, and Basic reservoirs. Joachim said about 800 to 1,000 Canada geese and 500 or so mallards have been wintering at the Vly Creek Reservoir.
"The birds choose (to overnight) at reservoirs because there are few homes around them and little water activity that would disturb them," he said. "Then, in the morning, they get up and take off (to forage for food)."
Both George and Joachim have a fairly good idea now how their birds spend their winter days.
The gulls and ducks that spend the daylight hours on the lower Mohawk are likely to overnight either at Tomhannock Reservoir, or above the Federal Dam on the Hudson River (near Green Island), or further south on the Hudson. Every morning, these waterfowl head west, the gulls feeding at such spots as the Colonie landfill above Cohoes Falls.
As the afternoon grows late, these birds begin to move back toward home, congregating in great numbers at various staging areas along the river: The wide bend east of the Route 9 bridge (George counted 2,700 gulls there last Tuesday), the rocks and pool below Crescent Dam, and the broad flats between Waterford and Van Schaick Island. Then comes the eastward flight around sunset, the gulls and ducks heading back to their overnight safe havens on the Tomhannock Reservoir or Hudson River.
Often, this homeward flight will begin with gulls riding thermals a thousand or more feet into the air, rising, without beating their wings, in beautiful, spiraling wheels. Eventually the gulls will "top out of the thermal," and develop a linear, purposeful flight.
George believes this flight plan allows the gull to spot open water. Has the day's cold frozen over the open water on the Tomhannock where the gulls stayed last night? If so, they will have to choose a different overnight resting place.
Once a few gulls begin to speed toward an overnight roost, other gulls crowding the Mohawk River staging areas quickly spot the overhead flight and play follow-the-leader, George said.
"It's a cascade of visual clues. These birds are coordinating their movements."
The mallards and other ducks will wait and fly back to their night roosts after the sun has set.
Canada geese that have overnighted at Tomhannock Reservoir most likely have spent the afternoon foraging for kernels of corn in nearby farm fields. But, unlike the gulls and ducks which leave en masse in the morning, the geese may come and go from the reservoir at different times during the day, churning up the patch of open water. This movement and the birds' body heat is what prevents the open from freezing over, George says.
"It's amazing. Waterfowl at the Bethlehem Reservoir keep five to eight acres of water open (by their movement). That is something that is not widely known."
Joachim, who has visited Vly Creek Reservoir at every hour of the day from 5 a.m. to 6:30 p.m. in recent weeks, has observed slightly different daily migratory patterns for the waterfowl who overnight there.
The geese, starting as early as 9 a.m., fly off to nearby cornfields for a day of foraging, the birds moving in groups that sometimes number in the hundreds. And do they make noise.
"When they take off, they are constantly honking," Joachim marvelled. "And when they return, those that are already there greet them with a lot of honking."
Mallards wintering at the Vly Creek Reservoir don't fly far, Joachim said. Throughout the day, they may take off in small groups of six or eight on short excursions, perhaps simply to stretch their wings or to scout area ponds for open water. But, during deepest winter, all of the smaller ponds in the area will be completely frozen over, the ducks quickly returning to the open water in Vly Creek Reservoir, where they can dive for food or perhaps skim the surface for algae.
A decade ago, Canada geese would not be seen around the Capital District during winter. George says there are several possible reasons why this has changed. It could be due to overhunting of geese at wintering grounds in Georgia, the Carolinas, and other points south. Or it could be due to a change in how corn is harvested, the new method leaving more grain in the field. Or - and George thinks this is the compelling factor - it could be due to milder winters, which makes it easier for the geese to keep stretches of water open at Tomhannock and Vly Creek reservoirs.
"That open water is crucial to their night safety," says George, who delights in describing the intelligent ways of geese and gull alike. "They will use open water very cleverly."
George turned his attention to area waterfowl eight years ago after an unfortunate turn with his studies of fish. He became extremely allergic to the Formalin solution used to preserve fish, his reaction to the solution so severe that it eventually destroyed the tympanic membrane in one of his ears.
He and his students now survey the birdlife at Collins Lake in Scotia daily, and canvass the Mohawk River-to-Tomhannock Reservoir system once every two weeks. It is research that George - dressed this day in wool cap and heavy green coat, binoculars hanging from his neck - admits is a source of great joy.
This last leg of the Mohawk is a world of astonishing beauty on a winter's day, the river lined by high bluffs, an afternoon sun painting the surrounding fields with a soft sienna brush. George and his students have become familiar with every bend and shallow of the river, their keen birding eyes able to distinguish a greater black-backed gull from a ring-billed gull or herring gull even though the birds may be little more than specks in their binoculars.
Along the way, there will be surprises, time for a birder's river tales, and the joy of seeing individual birds that have become old friends.
In the shallows below the dam being built below the Route 32 Waterford bridge, George's students pick out a small gull with light wingtips and pinkish bill that is being harassased and picked at by the others - the harassed gull is their first winter sighting of an Iceland gull.
"Good sighting, guys!" George calls out to his students, and then adds: "Many birders would be tickled to add that bird to their sightings."
Moments earlier, just above the Cohoes Falls, they had spotted a bald eagle flying over the gulls - a spotting that had come right on cue. George and his students have come to know the eagle so well they even know the tree it roosts in.
"We watched him fish," said Eric Blais, excited at his first glimpse of this great bird.
Added George: "The eagles are coming back. These great congregations of gulls support them. The eagle will single out a weak or sick gull or duck. Sometimes, the eagle may eat it right on the ice."
Yet, a day's trek along the Mohawk will bring forth a birder's laments, too. George points out an island above the Route 9 bridge called Long Island which once was home to the last big colony of black- crowned night- herons in the Capital District. To some, these birds may have been dirty, noisy, and odorous, but to George they were "lovely" birds whose slaughter was tragic.
"They were brutally shot off, we think, one day in 1953. They have never come back. It's a shame," he said.
George also worries about what will happen to the Mohawk River gulls when the Colonie landfill and other area dumps close.
"They are very adaptive, resilient animals. They could displace other animals, I don't know. It's tough to predict what will happen. All I know is we're trying to build a baseline (of information) so when the landfills closes we can say, 'Here is what is happening.'"
As dusk nears, George and his students are standing on the northern bank of the Tomhannock Reservoir, peering into their sighting scopes. They have counted 10,000 gulls along the Mohawk and are expecting that a great many will overnight at the reservoir.
A great horned owl greets them with a full-bodied hoot: Who Cooks For You, Who Cooks For You ... a lone fisherman drags a sled across the ice.
As the sun sets and the moon rises, a steady stream of ducks, honking geese and a few gulls splash down in the far-off spit of open water. Blais and Torgan somehow even manage to continue to identify and count the birds in the moonlight. The bird census soon numbers in the hundreds, but the great rush of birds that was expected never fully materializes.
Later, George learns from another team of his students that only 500 or so gulls showed up at Federal Dam on the Hudson that night. Where did the 10,000 gulls go?
Said George, happily: "They have moved somewhere and we don't know where. I think we still have a major overnight roost we haven't discovered."
[Note from Cliff Lamere: The bird that has the call described as Who Cooks For You is the Barred Owl, not the Great Horned Owl.]
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Feb 2015