American Tree Sparrows are not really associated with trees at all and are actually ground birds. The name comes from European settlers that thought that these birds looked like the Tree Sparrows they were used to seeing back home. American Tree Sparrows have a rusty cap and grey underparts with a small dark spot on the breast; they forage on the ground, nest on the ground, and breed primarily in scrubby areas at or above the tree line. In Michigan, winter is the time to find these birds. You will often find them scratching around on the ground for seeds that have fallen out of bird feeders. American Tree Sparrows need to take in about 30 percent of their body weight in food each day. A full day without food can be fatal, their body temperature will drop, and they can lose nearly a fifth of their weight in just that short time. This sparrow nests and winters farther north than any of its close relatives. Come spring, these small birds begin their long migration to breeding grounds in the tundra of the far North. Happy Birding!