How to Catch a Fly

Filed in Birding, Expert Articles by on November 12, 2013

TWG_story_birding06imgWhenever we observe birds, it’s fun to ask ourselves “what are they doing?” Birds spend much of their time foraging for food. Birds that live here only during the summertime are often insect-eating birds. A closer look at insect foraging behaviors provides fascinating insight into how some of our local birds make a living.

Most everybody recognizes swallows in flight. hey zoom around overhead like little fighter jets. Swallows circle around and change direction quickly much like bats in flight. This is because they are “hawking” insects while in flight. This method of capturing insects requires opening the bill wide and scooping up insects while in high-speed flight. Swallows, swifts and nighthawks employ this hawking technique regularly.

Woodpeckers are also easily recognized birds. Woodpeckers such as hairy and downy woodpeckers bore holes into wood or bark, and then utilize their exceptionally long sticky tongues to reach deeply into nooks and cracks to retrieve insects. Other times they simply chisel away at flecks of bark to reveal insects and larvae. This method is especially employed by the three-toed woodpecker. Recognize this local resident by the yellow dots on its forehead.

Sapsuckers are related to woodpeckers, but utilize a different technique. Sapsuckers drill sap wells into bark, usually as a series of holes neatly laid out in a grid pattern. They continually revisit the sap wells and glean insects stuck in the fresh-flowing sap.

Everybody can visualize a robin hopping around on the ground. Often robins are nabbing insects as they bounce from one locale to another.

Bluebirds are super-easy to recognize because of their brilliant blue color, and their peaceful nature. Bluebirds typically perch on fence posts, on wires, or in shrubs or trees less than twenty feet off of the ground. They use these elevated vantage points to watch for insects on the ground below, and simply use gravity to drift from their perch and pounce on an insect on the ground. The colorful American kestrel, our smallest falcon, also employs this method.

Warblers are easily recognized because of their bright yellow color. They bop around in the thick branches of shrubs and trees where it is wind-protected and insects thrive. They glean insects from leaves and twigs, and capture flying insects while constantly on the move hopping and fluttering through the tight branches.

Flycatchers are drab, plain gray birds that perch conspicuously on an open branch and hunt nearby flying insects. From their perch they “sally” out gliding on open wings, nab an insect in mid-air, and then return to the same perch. This is typical “fly-catching” behavior.

The other day I observed several magpies dropping from fence posts and walking in grass in a pasture. They were feeding steadily on grasshoppers. Without birds to feed on insects, insect populations would be much higher.

Ruby-crowned kinglets are difficult birds to see, but they are constantly heard in a pine forest singing loud and clear, “cheeseburger, cheeseburger, cheeseburger”. Not only do kinglets glean insect from needles high in the crown of conifers, but they also employ a unique technique called “hover gleaning”. Like a hummingbird hovers before a flower to lap up nectar, kinglets can hover in a similar fashion at the very tips of branches and snap up insects from this otherwise unexploited niche.

These are a few insect foraging behaviors that you can add to your bag of bird watching knowledge. As I sit here on my deck writing, a gray jay flew to within a few feet of me to nab an insect off of the deck. A Williamson’s sapsucker hawked a nearby flying insect while on the move from tree to tree. And a hermit thrush hopped through the yard in a robin-like fashion capturing insects from the ground. It’s all happening out here, when you take the time to immerse yourself in nature, sit still, and observe the activity that surrounds you.

Tom and Tanya Wiesen are owners of Trailwise Guides; a year-round Vail Valley guide service specializing in hiking, mountain biking, and natural history tours. Daily private tours are available. Contact Trailwise Guides at (970) 827-5363.

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