The arrival of hermit thrushes never fails to bring a special kind of joy to my heart.

Spring’s chorus is melodious and varied, but no song matches the hermit thrush’s in beauty. It is ethereal; and its echoing notes at dusk make it even more so, approaching the realm of the sacred.

I found a description of the song in the “Birds of North America” account that does it justice: “Richly melodious, haunting, flutey warble… phonetically, described as ‘oh, holy holy, ah purity purity, eeh sweetly sweetly.'”

As soon as I read this, I thought “hey, they got it right. How perfect!”

High praise aside, I saw something that made this thrush appear downright comical.

A few weeks ago I happened to look out my bathroom window as dusk was falling. There, a short expanse of lawn (not a real, “manicured” lawn – more an area of grass, assorted “weeds,” and clover) stretched down a short incline to meet the forest. Out in the middle of the space were two hermit thrushes that were exhibiting an interesting behavior.

They had fanned out away from each other. As I watched, each would extend a leg slightly forward, lightly touch it to the ground, then quickly vibrate it. It looked as if they were dancing a peculiar, high-speed little jig after being jolted by a current of electricity. After a few seconds of this strange foot quivering, they would observe the ground closely; at times this would be followed by a dash forward to snatch at something in the grass.

I realized they were foraging for insects amongst the clumps of old foliage. The foot quivering stirred their prey up out of hiding – and it seemed to be quite effective, judging by the number of times I saw the birds dart forward to snatch something from the ground.

This was the first time I had observed such behavior by hermit thrushes. Consulting my “Birds of North America” species account, I read that it has been documented before, in California of all places. I was further surprised to find that it may function as an aggressive meaning. When used against a dry surface, the observer noted it produced a sound similar to a rattlesnake’s warning, and seemed to function as “an ambivalent intention movement of conflicting drives, simultaneously to move forward (attack) or retreat (escape).”

A friend of mine dubbed it “the hermit jig,” and that’s how I’ll forever think of it, with a smile – no matter what the intent.

Chris Corio, a volunteer at Fields Pond Audubon Center in Holden, can be reached at fieldspond@juno.com