October 4, 2022
“This place is like a gadwall factory,” says Mark Mariano. Today I’ve joined Mark, a Butte-based ecologist who works for Rampart Solutions and who recently co-founded the nonprofit Montana Wetlands and Waterfowl, to survey ducks on Lake Helena. Here, just a few miles from the Montana capital, impressive numbers of waterfowl stop during fall migration on this shallow lake and the extensive marshes that surround it. And since 2020, Mark has been coming out here once a week, doing fall surveys to track the migrating ducks.
Mark’s work here is connected to a robust collaboration of biologists and industry, centered around Butte’s large, toxic Berkeley Pit and a very successful effort to prevent waterfowl mortality there. Mark’s fall surveys at Lake Helena are part of a regional bird monitoring effort. The goal: keep the Berkeley Pit team well-informed on fall waterfowl migration. Knowing what birds they can expect in the area, the team is well-prepared to scare ducks away from the hazardous waters of the Berkeley Pit.
Mark has been doing weekly surveys of the fall duck migration on Lake Helena for two years now. All of these surveys have given him a wealth of local knowledge about Helena’s waterfowl and their seasonal movements. So today, I get to learn from Mark about our local ducks. What does Lake Helena mean for our waterfowl?
Gadwalls on Lake Helena
Mark continues telling me about the gadwalls as he scans the western bay with his spotting scope. The gadwalls – subtle charcoal, black and tan ducks that somewhat resemble mallards – show up on Lake Helena in the spring. They mate and the females lay their eggs, scraping out a well-hidden bowl in dense vegetation near water. Soon after, the males leave, forming bachelor groups that spend the summer elsewhere. By August, the young have fledged, and several hundred of them join the flocks on the lake.
By now, the drakes have returned to Lake Helena, too. We can expect to have gadwalls here for the rest of the fall, until the lake freezes.
Coots and their associates
American coots are the most abundant waterfowl today. Just on this west end, we count 1900 of them, a large raft of stormy blue birds. A few gadwalls and American wigeons are mixed in with the raft. Coots, with their striking white bills, look similar to ducks. But they’re actually a type of rail (family Rallidae), not a duck. Like many dabbling ducks, coots feed heavily on aquatic vegetation.
“They’re really important for the other ducks because they dive,” Mark tells me. Wigeons and gadwalls are both dabbling ducks. Unable to dive for food, these ducks tip bottoms-up to feed on plants in the shallows. But Mark tells me that it’s very common to see wigeons and gadwalls mixing with flocks of coots. There, they wait for the deep-diving coots to resurface with plant matter, then try to steal the food from them.
Two weeks ago, Mark counted an astounding 17,000 American coots on the lake. This sort of change in a few weeks – from 17,000 to just a few thousand – makes it clear that the coots are moving right now. They stop to feed on Lake Helena, then continue south.
Lake Helena by boat
Now Mark has finished counting the waterfowl on this western bay. It’s time to start the second phase of the survey. We’ll launch the boat and make a circle around the entire lake, doing a comprehensive count of all the ducks we haven’t been able to see from the shore.
As soon as we launch, we begin making a clockwise circle around the lake. “Counting from the boat is so much more effective and easy,” Mark tells me. By covering the whole lake and checking the marshes on the sides, he is able to get a much more complete picture of the waterfowl here than a birder who only scopes from one edge.
Initially, Mark was doing spring surveys here, too. And his spring observations from the boat turned up something interesting. He learned that some very large flocks of snow geese stage on the inaccessible ponds along the south margin of the lake. It’s like “a mini Freezout Lake,” he told me – referring to the famous Montana lake where hundreds of thousands of snow geese stop in the spring. And because these ponds on the south side of Lake Helena are nearly impossible to access without a boat, local birders were largely unaware of this “mini Freezout” until Mark started his surveys.
Pipits, harriers, and diving ducks
Today, we find no snow geese. We can expect them to start passing over in late October or early November, when wintry weather begins to hit their major migratory staging areas in Alberta. The southeast side of Lake Helena is quiet today. From the flaming yellow sandbar willows (Salix exigua) along the shore, we can hear the occasional chip of a yellow-rumped warbler. Small flocks of American pipits flush from the lake’s edge with their electric sip-it calls. The water burbles smoothly under the bow of the boat.
Several northern harriers are circling over the marshes to the south of us. We spot a large raft of ducks out in the middle of the lake. They’re clustered along the line where the morning’s smooth water is giving way to a wind-driven chop. Mark has his eye glued to the spotting scope. He steers the boat with the trolling motor to pan the scope across the ducks. It’s largely diving ducks out there in the middle: redheads, ring-necked ducks, and ruddy ducks.
I spot a bald eagle sweeping languidly west over the lake. Mark hurries his duck-counting as the predator approaches. And then, as we had been expecting, the ducks leap into flight. Flock after flock move west in unison, impelled by the repulsive force of the eagle’s flight. The bald eagle continues onwards. The ducks settle in their new positions. But now we can see many more redheads than before.
Lake Helena and its marshes
“They’re just showing up out of nowhere – they keep flying in,” Mark exclaims.
The redhead flocks started to show up here two weeks ago, when Lake Helena was bursting its seams with coots. With all of the redheads, Mark says he’s surprised not to see any canvasbacks today – these large diving ducks often mix with the redheads here. Perhaps the season is a bit early yet for canvasbacks, though.
We check the ponds on the south side of the lake, which are surrounded by extensive, beautiful marshes of cattails and bulrushes.
“More gadwalls – surprise!” says Mark. Here we also see our first mallards of the day. Small groups of them lift off from this protected water, streaming obliquely past us.
South of us, in the distance, we can see a massive cloud of gulls wheeling. It’s a swarm of far-off specks over the valley, barely visible without binoculars. Presumably, they’re finding a hatch of insects or spiders to feed on. On the lake itself, over a hundred Franklin’s gulls are active. They bob on the surface and then take off, flying east over us in disorganized strings.
Completing the circle
We’ve passed the western bay now, where we counted the coots and dabbling ducks from the shore this morning. Our circle around the lake is coming to an end. There are some small groups of Canada geese in the pasture along the north shore. We scan them carefully, searching for anything different. For the past several weeks, Mark saw an unusually early snow goose with these Canadas, a surprise bird well in advance of the main snow goose migration. But today we see only Canadas: the snow goose seems to have moved on.
Mark pilots us back towards the boat launch. Another Lake Helena duck survey is in the books. Today we’ve dipped our toes into the fall river of waterfowl migration. It’s more than a river, really: it’s a continent-wide tide, inexorably southbound, as millions of ducks and coots evacuate the wetlands of the north in the face of the approaching winter. Lake Helena is one piece in this vast puzzle. And because Mark visits Lake Helena every week throughout the fall migration, today’s survey has the context of the whole seasonal story.
Problems with carp
Lake Helena isn’t perfect for duck habitat. Massive common carp (Cyprinus carpio) spend the summer here in large numbers, churning up mud as they root for food on the shallow lake bottom. Mark tells me that their feeding prevents submergent plants from growing, reducing the food available for ducks and coots. The carp also contribute indirectly to algal blooms. By removing aquatic plants, carp prevent these plants from absorbing the influx of nutrients the lake receives from the Helena Valley. Instead of aquatic plants, mats of algae grow in response to the nutrient surplus.
Mark knows of a solution for Lake Helena’s carp issues. Lake Helena is very shallow. During the winter, the carp return to the deep waters of Hauser Lake to overwinter. Mark tells me that a size-limiting gate in the dam at the Causeway, between Lake Helena and Hauser Lake, would allow other fish to move back and forth but would exclude most of the massive carp from Lake Helena. This strategy has been deployed successfully on southern Manitoba’s Delta Marsh. There, carp exclusion has improved water quality and boosted cover of aquatic plants.
So for Lake Helena’s carp problem, it seems that an answer is within sight. All that remains is all the work it would take to bring this idea from concept to reality. But in the meanwhile, carp notwithstanding, Lake Helena and its surrounding marshes are one of the Helena Valley’s treasures.
Helena, the valley of the ducks
“Helena is very ducky,” Mark tells me. And indeed, between Lake Helena and the Helena Regulating Reservoir, birders have recorded a whopping 33 species of ducks, geese and swans in the Helena Valley. Why all this diversity?
It’s because of Lake Helena and places like it. Because of these ponds, open waters, and marshes, we can watch tens of thousands of coots stopping here in the fall. We can see the gadwalls and American wigeons trying to steal their food. In the spring, we can look for the flocks of snow geese as this place becomes a “mini Freezout Lake.”
I hope that there will always be wetlands like this in the Helena Valley. And if we can exclude the carp, how many more ducks could we support here?