Note: This story is the third and final in a series about Lake Helena and getting to know a place in nature over time. In case you missed the first two, you can find them here:
Part 1: Shorebirds to the Arctic
Part 2: Of bitterns and bank swallows
Enjoy!
It’s August 6 in the bowl of blue mountains that is Montana’s Helena Valley, and the sunrise is scarlet against the rainy blue-purple of a thunderstorm cell. The sandhill cranes (Antigone canadensis) give their resonant calls from the edge of Lake Helena’s marsh. Otherwise, the cattails are quiet where two months ago they were bursting with the songs of the marsh wrens (Cistothorus palustris), common yellowthroats (Geothlypis trichas), and red-winged blackbirds (Agelaius phoeniceus). The blackbirds seem to have left their natal marsh entirely, aggregating now into post-breeding flocks.
The forecast had called for very little wind this morning, and so Grant Hokit and I had decided to bring our kayaks to Lake Helena and check up on shorebird migration. But the thunderstorm had other ideas. I first heard it rumbling off to the northwest around 4:00 am, when I was still mostly asleep in my bed. By now it’s moved east, almost beyond the valley, as the sandhill cranes greet the red sunrise. But in its wake is the outflow breeze—not a gale by any means, but enough to bring up a steady swell on the lake. The waves jostle our boats and push us around, making observation difficult.
Shorebirds at the delta
But when we arrive at the delta, we find it bursting with migrating shorebirds. Many of these species look quite similar at a glance, and we have to pay careful attention to their shape, size, and leg coloration to tell them apart. We spot a least sandpiper (Calidris minutilla), a tiny bird with pale yellow legs and with a quarter the weight of a robin. Nearby is a semipalmated sandpiper (Calidris pusilla), slightly larger and with jet-black legs. A bit farther away we notice a western sandpiper (Calidris mauri), a very similar-looking species with a longer, gently curved bill.
Along with these three tiny shorebirds, three pectoral sandpipers (Calidris melanotos) are foraging. As heavy as a robin, these ones have yellow legs like the least sandpiper. Finally, we count six Baird’s sandpipers (Calidris bairdii), shorebirds intermediate in size between the western and the pectoral sandpipers. Baird’s sandpipers have long wings, evident even when a bird is perching because of how they poke out behind the tail.
Baird’s sandpipers and the wind
All six Baird’s sandpipers have pale-edged feathers on their backs, which tells us that they’re juveniles. They’re attempting fall migration for the first time ever, and by themselves—their parents left their Arctic nesting grounds earlier, leaving the juveniles to fend for themselves. For the Baird’s sandpipers, Lake Helena is a stopover site in an incredible migratory journey from the Arctic to their wintering grounds in southern South America—a journey that, for some, spans over 9,000 miles. I wonder if the thunderstorm brought us this diversity of sandpipers, forced down to earth from their nocturnal flight.
Now the wind is shifting from easterly to northerly and is getting stronger, lashing across the cattails. The swells have almost become whitecaps—and our return journey will require paddling into the wind. We know we should probably turn around now, but we make the dubious decision to paddle on a bit farther and check the southwestern bay before we head back. We can hug the shore on the way back, we tell ourselves, lessening the force of the waves.
Waterfowl and waves
The bay is alive with waterfowl. A hundred and twenty northern shovelers (Spatula clypeata) erupt from the water as a lone trumpeter swan (Cygnus buccinator) swims along a backwater and a few redheads (Aythya americana) and common mergansers (Mergus merganser) eye us cautiously. The shrubs along the edge of the bay are protecting this area from the wind.
Now we’re ready to face the waves. First we stow our cameras and my microphone to keep them dry. With the lake so rough, we won’t be doing much bird observation on the way back.
Our kayaks plow forwards through the agitated waves, battling the headwind. Despite my best efforts, I can’t avoid a few splashes over the bow. By the time we make it back to the boat launch, I’m soaked—and so is my backpack.
A change in the shorebirds
It’s two days later when we return to the lake, my backpack dry once again. The sky is overcast with soft gray clouds, the sort of gray that smells like the possibility of rain. It’s a much-welcome change from July’s gray, that harder gray of wildfire smoke and heat wave.
In these short 48 hours, the shorebirds have changed dramatically. Gone are the least, western, and pectoral sandpipers. Meanwhile, the juvenile Baird’s and semipalmated sandpipers are much more numerous. We count at least 11 Baird’s and eight semipalmated. A breeze has brought up a light chop to the water, pushing small waves against the sandbar as Baird’s sandpipers call and the semipalmateds squabble with them over foraging space. A greater yellowlegs (Tringa melanoleuca) leaps into the air, giving its piercing tew-tew-tew! call. These notable changes in just a couple of days highlight the pace of migration. Evidently, many of these shorebirds have already continued southward.
The Helena Regulating Reservoir
The following week I decide to kayak at the Helena Valley Regulating Reservoir, the other major stopover site for shorebirds in this valley. The reservoir, surrounded by a ring of cottonwoods, serves to store irrigation water and deliver it to farming operations in the valley. It lacks the extensive marshes of Lake Helena but whenever water levels are low enough, the ample mudflats around its margins provide a roosting habitat for gulls and pelicans as well as a foraging habitat for shorebirds. And there’s much less traffic noise here than at Lake Helena, so close to the interstate, making this spot much better for sound recording.
As I launch my kayak in the pre-dawn darkness, I’m immediately confronted by the sheer numbers of birds using this different but also important stopover site. The Canada geese (Branta canadensis) are all around me, in small groups and large aggregations. Counting them by tens in the weakening darkness, I estimate that there are 650 of them within sight of me.
The hundreds of gulls around me are unidentifiable white ghosts in this faint morning light. Later, I’ll be able to confirm that most of them are ring-billed gulls (Larus delawarensis), our most common species in this region.
Sandhill cranes in the darkness
When I first hear the sandhill cranes, I don’t think too much about it. Their voice is so familiar now, this weird, amazing sound of the early morning marshes, fields, and lake edges. But then I hear cranes from another direction and I start wondering—how many sandhill cranes are there here?
The northeastern sky is getting lighter, though the sun hasn’t yet risen. A few groups of Canada geese have begun to depart from this safe overnight resting spot, calling loudly as they take off. I assume they’re bound for some local grain fields to get breakfast. By now it’s light enough to see the sandhill cranes perching on the mudflats—and it’s an impressive grouping. I scan across the edge of the reservoir, counting sandhill cranes. 42, 43, 44, 45…. Counting them by ones, I determine that there are at least 93 of them here this morning.
More Canada geese take off, one group after another. A few cranes have already departed, but most of them remain. When will they fly out to forage?
The music of the sandhill cranes
As the sun rises over the mountains in a peachy orb, the cool air erupts with crane music. One group after another flaps heavily into the air and the cranes fly past me in straggling lines, heading east. I assume that they, too, are finding a field in which to feed for the morning.
A few cranes wait until the light of the sun is illuminating them fully. Then they depart as well. They leave me with two Caspian terns (Hydroprogne caspia) flying low, calling harshly as they prospect for fish, while 290 ring-billed gulls perch on the mudflats. And they leave me with the echo of their voices reverberating in my mind as I give thanks for wetlands where cranes and shorebirds can stop over and I try, without success, to imagine a juvenile Baird’s sandpiper flying 9,000 miles over the rivers, mountains, interstates, and landfills of a continent where I’ve lived my entire life and whose geography I still don’t comprehend.
In Montana, Montana Audubon coordinates the Important Bird Area program, which includes the Lake Helena Important Bird Area. To find out more about this program and Montana Audubon’s other conservation and citizen science initiatives, visit mtaudubon.org. And if you visit Lake Helena, consider submitting your bird sightings through eBird to contribute to our collective knowledge of this place!
Further reading
Billerman, S.M., Keeney, B.K., Rodewald, P.G. & Schulenberg, T.S. (editors). (2022). Birds of the World. Ithaca, NY: Cornell Lab of Ornithology. https://birdsoftheworld.org/bow/home