29 March 2013

Friday Field Notes: Bluebird Days

Lately, it seems as if the sky is blue more often than not. There is nothing quite like waking up to a brisk, bluebird day in the spring in Montana. The growing strength of the sunshine warms the skin and raises hope that summer is not far away. But it isn't just the sun that illuminates the landscape this time of year.

On a recent outing up Missoula's Waterworks Hill, I heard a soft, chattery whistle sound. Initially, I was caught off-guard, but rather quickly it hit me: Mountain Bluebirds. I panned around, searching for the magnificent cerulean birds, and sure enough, there they were perched on a power line right above me. I don't know why I was so surprised to see them; the sweeping grasslands are perfect bluebird habitat that the birds return to every year. Perhaps it was simply the abruptness with which they arrived. The previous day, there were no bluebirds to be found. Now, there were dozens.
A male Mountain Bluebird with his lunch.
Mountain Bluebirds (Sialia currocoides) are a small member of the thrush family, which includes common birds like the American Robbin, Hermit Thrush, Townsend's Solitaire, and other bluebirds. While common throughout Montana and most of the interior West in the spring and summer, Mountain Bluebirds move as far south as Central America to winter. Rather interestingly, Mountain Bluebirds can tolerate colder habitats than other bluebirds, and some migrate westward to the Sierras for the winter. I suppose they must be pretty hearty, as their early return to the Northern Rockies inevitably results in them being forced to weather a handful of spring snowstorms.

Unlike many bird species, Mountain Bluebirds have largely benefited from human settlement and activity in the West. The clearing of previously forested lands and the expansion of agricultural development has opened up millions of acres of new bluebird habitat. They also have been helped by our affinity for them - there must be hundreds of thousands of "bluebird boxes" scattered across the western United States.

A female Mountain Bluebird hovers while searching for insects.
Like most thrushes, Mountain Bluebirds feed primarily on insects, although their diet is supplemented throughout the year with small fruits and seeds. What sets this particular bird apart from its close relatives, however, is the way in which they sometimes acquire their food. Mountain Bluebirds can often be seen hovering in place, not unlike American Kestrels, as they scan the ground for insects. If prey is found, they quickly swoop down to the ground like a raptor pouncing on a small rodent. It is a spectacular sight to behold, made all the wilder and more intense by the bird's stunning colors.

Over the coming days and weeks, more and more of these magnificent birds are sure to arrive. Their presence on Waterworks Hill and other grassy fields across Montana is likely to be accompanied by that of a close rival, the Western Bluebird. As mating season takes off and the struggle to establish a territory reaches fever pitch, Mountain Bluebirds will clash with Westerns as well as members of their own species over nesting boxes and territories. It will be a spectacle, no doubt. I, for one, will be watching eagerly.

Have you seen any bluebirds yet this spring? Do your bluebird boxes have new residents? Be sure to let us know in the comments!


  1. Hey, I've been seeing them all around the open slopes of Sentinel where I run almost daily. Being from Oregon, this is my first spring in MT and I LOVE these birds. I see them in flocks of 5-10 doing their "hovering" thing landing here and there on grass and twigs. SO BLUE. Love their sound too...reminds me of waxwings for some reason. Thanks for this post!

  2. We saw one and got within 20 feet of it before it flew away. Pactola Lake, South Dakota.