Bluebirds are some of our most popular birds of spring. Let’s talk about two that frequent California, the Western Bluebird and the Mountain Bluebird. While these are both bluebirds, they’re very different in terms of how they migrate. The Western Bluebird is one of the least migratory of all the bluebirds, while the Mountain Bluebird is perhaps the most migratory. Here's some video of a Mountain Bluebird:

More about them below:

Western Bluebirds live in California throughout the year, and their migration is more one of changing altitudes than dramatic movements north and south. In the fall, a lot of these birds will come out of the mountains for warmer areas, and then return in the spring. Western Bluebirds have been in decline in recent years, but the fact that they take to bird boxes so well has made it possible for people to help them considerably. Here at Audubon California, we put up a lot of bluebird boxes on our properties to help these great birds.

As we said earlier, the Mountain Bluebird is considered the most migratory of all the bluebirds. While we do have a year-round population of them in the larger northeastern part of the state, we also have wintering birds that reside in northern California and the far south. For the most part, Mountain Bluebirds are wintering in Mexico and parts of Texas and Oklahoma. In the spring, the bird heads up to breeding grounds in Oregon, Washington, Idaho, Canada and Alaska. To show how the Mountain Bluebird moves around the state in the spring, check out the maps from January, February and March. To see what’s going to happen in April, check out this map from last year. Note that most of the birds are gone to points north, except for a few sightings in the high mountains of the Sierras.

So, how does one tell them apart? Well, there are all kinds of differences between males and females and mature and immature. But our basic trick is that if the bird has a rusty chest, it's likely a Western Bluebird. If it has a white belly, it's likely a Mountain Bluebird. We're curious to hear what your sight clues are.

(photo of Mountain Bluebird by USFWS)