Budding trees, blooming flowers, and baby bunnies galore are all signs of spring's arrival in Colorado. And with the spring season also comes the return of many birds to the Centennial State.

Backyard birdwatching is made easy thanks to the vast array of avian species that we have here. Spring is a great time to see hummingbirds, as they make their way through Colorado while migrating north.

During the annual hummingbird migration, Colorado plays host to tons of these tiny, fluttering birds as they follow the path of hatching insects. Most of them stay here for about five months before continuing northward to their breeding grounds. Migrating hummingbirds typically arrive in late April and stay until early September.

Related: When Should You Put Your Hummingbird Feeder Out in Colorado?

As pollinators, hummingbirds fly by day when nectar sources, such as flowers, are more abundant. Impatiens, lupine, and trumpet vine are excellent plants to have in your garden to attract hummingbirds.

On the Birds of Colorado Facebook page, multiple Colorado residents have reported spring hummingbird sightings in cities including Conifer, Denver, and Pagosa Springs.

Colorado's most common native breeders are broad-tailed hummingbirds, and therefore, are the type that's most frequently seen here. Black-chinned and Calliope hummingbirds also breed in Colorado, too.

Scroll Through Some of Colorado's Rarest Birds

The Colorado Bird Records Committee of Colorado Field Ornithologists reports an amazing 514 species of birds can be found in the Centennial State. Scroll through the photos below to see some of the rarest birds you'll encounter in Colorado.

Gallery Credit: Wes Adams