Some swallows rent, others build |

Some swallows rent, others build

Tom Wiesen
Photo by James C. Leupold/U.S. Fish & Wildlife Service An American tree swallow is shown perching between flights. Swallows are often confused with swifts, however swifts usually don't perch.

Walk outside on a sunny midsummer day and look skyward from an open vantage point. Chances you’ll see a swallow in flight within the first minute.Swallows look like miniature fighter-jets gliding and soaring over open spaces. Zooming around at high speed, they gobble up insects with wide-open mouths. They’ll commonly circle back through a swarm of insects, and at times there are feeding frenzies with many swallows dive-bombing into an especially thick cloud of their tiny prey.Swallow parents are now hard at work gathering insects to feed their fast growing chicks. This is a time of year when you can see the parents coming and going from the nest. Both mom and dad cruise for insects, store them temporarily in their esophagus, then return to the nest and regurgitate food to the hungry babies.

Eagle County is a great place to watch swallows, because six species of swallows summer here. Since swallows rely on fresh hatches of flying insects, they arrive here in early summer when consistent warm temperatures ensure regular insect hatches. It is common to see swallows lined up on a telephone wire on a frosty summer morning, because if it’s too cold for insects, there’s no reason for them to fly. Swallows will simply hang tight until the warm morning sun brings about another bounty of nutritious insects.Swallows migrate north to Eagle County from as far south as Central America. Upon arrival, swallows search out open areas rich in flying insects and suitable nesting sites.There is great diversity in the types of nests different species of swallows build. For instance, the American tree swallow and the violet-green swallow use of an old woodpecker holes. Visit an aspen grove and look for neatly bored, 2-inch holes about 10 to 15 feet off the ground. Without the woodpecker to make its home, these swallows would be left out in the cold.

Cliff swallows build gourd-shaped mud nests under overhanging rock cliffs, under the eaves of buildings and under bridges. Cliff swallows need a nearby source of mud, which they scoop up by the mouthful, mix with spit, and deposit on their structure like a mason laying tiny mud bricks. A thousand mouthfuls later, they have a hanging clay home, with an entrance hole just large enough for the birds to come and go.Readily observe cliff swallows visiting nests and feeding babies the next time you go to the Minturn Market. There are many fine nests under the eaves of the Cowboys and Indians building.Like its cousin the cliff swallow, the barn swallow also uses mud to build its cup-shaped nest on a ledge inside a barn, under a bridge or on a cliff. Barn swallows can be identified in flight by their long, graceful forked tail.Northern rough-winged swallows and bank swallows excavate their nests in sandy earthen banks. Visit a local river and look for a sandy cliff face with two-inch holes.

These swallows burrow in as deep as 6 feet, pecking with their bill, scratching with their feet and removing the debris with their wings and feet.Have you ever wished that the outdoors were insect free? We must remember the role insects play in pollinating our colorful wildflowers, feeding our bird and filling the bellies of the trout swimming in our gold medal streams. Insects make summer here in Eagle County as sweet as honey. Tom and Tanya Wiesen are owners of Trailwise Guides, a year-round Vail Valley guide service specializing in daily private outings in the White River National Forest. Reserve a day of personalized instruction for wilderness hiking, mountain biking, or bird watching. Improve your natural history skills with Trailwise Guides. (970) 827-5363

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