September 13, 2022
It’s the sort of day when Spokane Bay is covered with birds and anything seems possible. A great blue heron is wading in the shallows, stalking prey. I can’t see what it’s catching, but every few steps it plunges its beak forward, stabbing a small food item from the water. In the cattail marsh behind the heron, the common yellowthroats are chipping constantly as they dart cryptically through the stems. The cattail leaves are just beginning to turn yellow.
Closer to me, there are dozens of birds in the low thicket of snowberry, rose, and golden currant that borders the marsh. It’s a talkative community, but one that largely stays hidden. With some patience, though, a few of these birds begin to show themselves among the shrubs. There are fat, gray song sparrows making their chimp calls. The Lincoln’s sparrows, their smaller, more crisply-streaked cousins, are pausing here as well. Once in a while, I can hear their sharp zeet calls. There are young, drab white-crowned sparrows here, along with bright yellow Wilson’s warblers. Several gray catbirds pop up from the cover of the snowberry, one of them making an emphatic, sharp call.
Fall migration is in full swing now – in spite of the wildfire smoke, which is back after a few days of respite late last week. And with all of the birds on the move, Spokane Bay is bursting with activity.
Food among the algae
A sora rail has crept out from the cattails that border the shallows of the bay. It looks like a small chicken as it wades out on top of a mat of green algae, picking mysterious foods from among this carpet. A marsh wren has started singing from the cattails.
Farther out on the bay, the algae has decreased notably since last week. Perhaps the cool nights have discouraged its growth. More ducks are showing up on the bay: a handful of American wigeons and northern shovelers have joined the mallards and mergansers here.
Suddenly, a merlin makes a low pass over the marsh, a whoosh of fast-winged falcon trying to hunt lunch. The birds of the marsh have lucked out this time: they’re all well-hidden by the snowberry and cattails. The merlin continues on, and the momentary threat of sudden death has passed.
Merlins, sharp-shins, and peregrines
With all of the songbirds and ducks stopping here, Spokane Bay is getting to be a predator magnet. Just a few minutes ago, I spotted a sharp-shinned hawk circling over the bay, rising higher and higher on a thermal. And still earlier, I spotted a much larger predator here.
I had been hearing the nasal calls of the magpies for a while, absentmindedly. Finally, I decided to take a look at the group that was perching high on the ridge. What were they doing? That was when I saw ten black-billed magpies congregated around a large, dark raptor perched on a snag. It was a peregrine falcon: duck-hunter extraordinaire and incredibly long-distance migrant. Some peregrines from the Canadian tundra spend the winter in Buenos Aires, Argentina, hunting pigeons and bats over the streets of that massive city.
But today, it was clear that this peregrine wasn’t enjoying an easy meal of city pigeons. In fact, it seemed to be having a very bad morning. For a while, the falcon resolutely managed to ignore the harassment of the magpies. But finally, it was all too much. The peregrine took off, evidently irritated, heading south along the ridgeline. A hundred yards away it landed again, apparently hoping for some peace, but the magpies followed it like a cloud of bad news. Pestered to desperation, it took off again and continued south, out of sight. But minutes later, it was back, still trailing a cloud of determined, hostile magpies.
Predators and habitat
Why were the magpies being so hostile?
Peregrines don’t just eat ducks. And it seemed that these magpies knew in their bones what I had learned five years before, on the other side of the Helena Valley. On that October day, I watched a migrating peregrine capture an unwitting magpie, plowing into it in a high-speed dive. Today, the message of the magpies was clear: get out! You aren’t welcome here.
It’s on a day like this, when we’re surrounded by fall migration, that the importance of habitat becomes especially obvious. All of the birds stopping over here are hungry. They need sources of food – and hiding places where they can be safe from merlins and peregrines. At the same time, these migrating merlins and peregrines need to hunt: they also have an incredible migration to fuel.
How fortunate, then, that we have cattail stands to feed and shelter the common yellowthroats and marsh wrens. We have an aquatic food web that supports soras, ducks, and great blue herons. We have thickets of shrubs where dozens of sparrows and Wilson’s warblers can find food and hide from predators. And in the midst of this bird oasis, there’s also food for the falcons and hawks. I’m glad this is here.