There have been several reports of Blue-gray Gnatcatchers (Polioptila caerulea) seen in the province since early April. These are exciting to see since we are out of their normal range. Their normal summer range is the central US with some occurring into New England. They winter from southern California to the Gulf coast and the Carolinas, southward to Mexico and the Caribbean islands. For a full discussion of this species, please search this blog (November 16, 2017).
Gnatchatchers are tiny, active insectivores. They raise and flick their tails (constantly!) supposedly to raise insects which they then devour. One time I watched a flock of these birds and they were very active, flicking their tails and making short flights in every direction to catch insects around a salt water wharf. They would quickly move from bushes and low shrubs to seaweed covered rocks. They certainly were having a good feed!
Gnatcatchers resemble hummingbirds in their nest sites and nest structure. They build a tiny cup nest which they place on top of a horizontal branch and then decorate with lichens. We have seen many hummingbird nests so would probably overlook a gnatcatcher nest for a hummingbird nest. The Gnatcatcher nest would be a bit larger, the gnatcatcher being 10.8 cm long (a lot of that being tail) compared to the 8-cm Ruby-throated Hummingbird. And, the Blue-gray Gnatcatcher weighs 6 grams compared to the 3 gram weight of the Ruby-throated Hummingbird.
The Blue-gray Gnatcatcher is a member of the Polioptilidae family (gnatcatchers and gnatwrens). It was first described by Linnaeus in 1766. There are 4 species of gnatcatchers in North America; California Gnatcatcher, Black-tailed Gnatcatcher, Blue-gray Gnatcatcher, and Black-capped Gnatcatcher. The other 3 species are birds of the far west and south.
The Blue-gray Gnatcatcher is the only truly migratory member of the family and has the northernmost range. Fortunately for us, this species is expanding its range northward. So watch out for them with chickadees and kinglets or with warblers. They are a beautiful sight.
Sightings this year have occurred on Grand Manan where the photos above were taken and in the southeastern part of the province. Since they could occur anywhere in the province, keep this species in mind. They prefer to nest in swampy woods, so look for their nests when out birding or botanizing. They nest as close as Southern Maine. There was one report of a nest at Sackville in 1989. Given this, we are likely to have a nest or two here this summer.
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