Top Ten Birds of Aspen

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1. White-tailed Ptarmigan
2. Brown-capped Rosy-Finch
3. American Dipper
4. Western Tanager
5. Three-toed Woodpecker
6. Olive-sided Flycatcher
7. Broad-tailed Hummingbird
8. Virginia’s Warbler
9. Red Crossbill
10. American Robin

From the continental divide to the Colorado River, the Roaring Fork Valley’s diverse life zones are home to more than 165 species of resident and migratory birds. Spanning waterfowl, warblers, woodpeckers, owls and more, distilling them down to a list of the “top ten” is no easy task! On the other hand, there is a handful of birds that are especially iconic of our area and its mountain environs:

The white-tailed ptarmigan is the only bird in North America that inhabits the alpine ecosystem year-round. At about 12,500’ elevation, krummholz gives way to alpine tundra where these birds disappear into their surroundings by way of an ongoing molt over eight months of the year, changing from pure white in winter to mottled browns and grays in summer. Powered by willow buds, forbs, flowers and insects, ptarmigans conserve vital energy by burrowing into snowbanks and grow feathers on their feet that work like snowshoes.

Another denizen of the Colorado’s highest peaks, the brown-capped rosy-finch nests in rocky crevices up to 13,800’. These birds feed on seeds and insects on the surfaces and edges of summer snowfields, and on wind-blown ridges and exposed ground in high mountain valleys during winter. Their worldwide range is the southern Rockies, making them truly iconic of our local mountains.

Clear, cold, rushing mountain streams and rivers are home to the American dipper, one of the world’s only aquatic songbirds. Equipped with thick, waterproof plumage and an extra, inner eyelid that works like swim goggles, dippers enter rushing water to forage on aquatic insect larvae that cling to rocks on the riverbed. The dipper makes the “Top Ten” list because they are commonly seen on the Aspen area’s many rushing creeks and mountain lakes, including Maroon Lake.

One of Aspen’s most colorful birds, the western tanager is striking with its orange, yellow and black plumage. More common than you may think, these birds nest in open, mixed woodlands where the fruits and insects they eat provide the special pigments that color their vibrant feathers. Outside of the summer breeding season, western tanagers migrate to Mexico and Central America.

Most of our local woodpecker species sport a bit of red in their plumage, but for the three-toed woodpecker, it’s a daub of golden yellow on the forehead. These woodpeckers are uncommon in the high-elevation forests of spruce and fir that blanket peaks and ridges around Aspen, in fact, their North American range comprises the boreal forest of northern latitudes, with an extension south along the Rockies throughout Colorado’s mountains. Look for flaked bark on the ground beneath tree trunks, a sure sign of the three-toed woodpecker’s foraging.

Another subalpine forest specialist is the olive-sided flycatcher, one of the larger flycatchers around Aspen. These uncommon birds are often found in ragged forests impacted by avalanche, high winds, or fire, where abundant snags and bare branches provide their favored perches from which they can easily spot the flying insects they eat.

Hummingbirds bring smiles to everyone’s face, birders and non-birders alike! The most common local breeding hummingbird is the broad-tailed hummingbird, nesting high into the subalpine forest where the male’s musical wing trill can be heard in nearly every wildflower meadow. Feasting on a diet of nectar and tiny insects, these birds are important pollinators in our mountain ecosystems. Look for a dusting of yellow pollen on the chins or upper bills of broad-tails when they visit your hummingbird feeder.

In the Roaring Fork Valley’s lower elevations blanketed by mountain shrublands and pinyon-juniper woodlands, Virginia’s warblers flit among foliage, gleaning tiny insects from leaves and twigs. This warbler is best found by listening for its song in early summer. Those who persevere to catch a glimpse of this retiring warbler are rewarded by its delicate markings: a complete, white ring around the eye and soft-edged patches of bright yellow on the chest and under the tail.

Red crossbills are uniquely equipped to feed on the seeds of conifers, using their specialized bills like pliers to pry apart pinecone scales and access the seeds inside. While many other birds feed on pine seeds, crossbills are far more efficient, consuming at a rate of one seed every 12 seconds or up to 3,000 seeds per day. Watch for these birds in flocks and listen for their “kip-kip kip-kip” flight calls as they move about the mountain forests in search of rich cone crops.

One of the most familiar and versatile birds in North America, the American robin completes our “Top Ten Birds of Aspen” list. These widely recognized birds nest in most Aspen habitats, from residential backyards to spruce forests at tree line. They can also be seen locally throughout all seasons. In fact, every winter, some robins forego migration and stay locally in spots with warmer microclimates and bare ground. Fruits of serviceberry and chokecherry supplemented with invertebrates in the leaf litter sustain these birds through the winter.

Enjoy learning about and observing Aspen’s top ten iconic birds and more with ACES! Ask for a local bird checklist at our Hallam Lake visitor center, pick up a copy of Birds of Aspen and the Roaring Fork Valley, or join one of ACES’ birding outings offered year-round.