By Bob Walker
From spring to fall, as you hike along the canyons in Los Alamos County, you are likely to see flocks of fast-flying birds swooping in large circles and catching insects. Is it a swift or a swallow? While there are four or five different kinds of swallows that have been seen here, only one swift has ever been reported in Los Alamos County – the White-throated Swift (Aeronautes saxatalis). Swifts and swallows look similar on the fly, but if you look closely, there are a few tips that will help you tell them apart. Swifts have long slender wings that flap as a unit, because the inner half of the wing is very short. That anatomical difference makes their flapping look very stiff, as if their wings are not bending at all. Swifts will coast or glide more than swallows, and their wing shape is curved, like a scythe. The wing anatomy of a swift resembles that of a hummingbird, and in fact, biologists consider hummingbirds to be the biological descendants of swifts, and have placed them in the same order.
White-throated Swifts have white bellies and throats with a black vest under their wings. Except for their wing shape and flying style, from underneath they most closely resemble our summer Violet-green Swallows. Swifts eat a diet of flying insects and spiders, and spend their entire day flying, never perching. They roost in large groups in cracks in cliffs and rocks, and spend no time on a nest except to breed. They can be found in Los Alamos County from mid-March through mid-October, and for the winter they migrate as far south as Central America, although little is known of the migration routes they use. White-throated Swifts can be fairly long-lived – some banded birds have been recovered up to ten years after they were first banded.
As White-throated Swifts fly overhead, you may hear their chattering, since they are quite vocal. Here is a sample:
Look for articles about White-throated Swifts on the web pages at identify.whatbird.com or allaboutbirds.org or the PEEC Nature Guide. Enjoy more beautiful photos of White-throated Swifts at the Brian Small website, or by carefully searching images on Google or Flickr.
PEEC is partnering with Bandelier National Monument for the Year of the Bird, 2018. Bandelier chose the White-throated Swift as the bird of the month for March, 2018.