Blue-gray Gnatcatcher
Polioptila caerulea
Content and photos by James Giroux
Unless you are a birder, the Blue-gray Gnatcatcher might be one of those birds you never knew existed. This, despite the bird being a year-round Austin resident. One reason this bird goes unnoticed by the general population is that it is among the smallest songbirds in North America. On average it weighs .2 ounces or 5.7 grams. In other words it would take five of these birds to make one ounce! It weighs significantly less than the Blue-throated Mountain Gem hummingbird (7.6 grams), and our Lesser Goldfinch (8.5 grams). Because it is so tiny, it is often heard before it is seen. When it is active, it is usually a vocal bird, giving a nasally or wheezy call.
Despite its name, gnats are not its primary source of food. Instead, it eats a wide variety of “bugs,” including spiders, flies, moths, and caterpillars. To flush prey from its hiding spots in the vegetation, the bird flicks its wings and long tail. Often exhibiting foraging behavior similar to a flycatcher, it will chase down flying insects. With impressive agility, it can hover and change directions quickly to snatch prey from the air.
There are three other species of Gnatcatchers in North America, all of which (in my opinion) are poorly named. Three out of four have black caps, and yet one is called the Black-capped Gnatcatcher. Three out of four can be found in California, and yet one is called the California Gnatcatcher. All of them have black in the tail, and yet one is called the Black-tailed Gnatcatcher. Argh!
Source: Cornell Lab, All about Birds
Of these four Gnatcatcher species in North America, the Blue-gray is the northernmost-occurring, and is the only one of the four that migrates. Since the year 2000 its range has expanded 200 miles to the north due to changing global temperatures.
September is probably the best month to see Blue-gray Gnatcatchers in the Austin area. I often see three or four at a time in my back yard during this month. Many will stay throughout the winter, but most of them are just passing through, heading further south. The bar graph below shows the frequency of this bird in Travis county from month-to-month.
Source: eBird.org
Fledgling
The Blue-gray Gnatcatcher can be found from coast-to-coast in the United States in both summer and winter. In the Austin area, you can find this bird almost anywhere there are trees, especially in September. Listen for its cat-like nasally mew sound, then try to get your binoculars on it before it jumps to the next branch. Good luck!
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