Picture walks: Mother Nature’s angry bird

By Jeanne Church

In late April, while I was at the Wolf Lake State Fish Hatchery taking pictures of all the beautiful yellow-rumped warblers, another little bird suddenly caught my eye. It was an elusive blue-gray gnatcatcher that barely came into focus before disappearing into the trees. I wasn’t at all sure I’d gotten a decent shot.

Later, when I brought the picture up on my computer, I was delighted to see that it wasn’t just a decent shot, it was an unusual one. By capturing this flighty little bird head-on, rather than in profile, I saw a real-life version of the cartoon character “Angry Bird.” Only the male blue-gray gnatcatchers have the distinctive black “V” shape above their eyes that gives them such a menacing look, and it’s only present during the mating season.

Blue-gray gnatcatchers are very tiny, extremely active woodland songbirds that tend to stay high up in the trees—all of which makes them difficult to find and to photograph. At a mere quarter of an ounce, the blue-gray gnatcatcher is only slightly bigger than a ruby-throated hummingbird! You are more likely to hear one than to see one! For an excellent resource on learning their songs and calls, go to this website: allaboutbirds.org/guide/Blue-gray_Gnatcatcher/sounds

In spite of its name, the blue-gray gnatcatcher rarely eats gnats! It consumes a wide variety of other insects including flies, wasps, beetles, caterpillars, and spiders. The smallest insects are swallowed immediately, but the larger ones need to be beaten against a branch, and the wings torn off, before the gnatcatcher can swallow them. To catch all these delicious insects, the blue-gray gnatcatcher must either grab them out of the air, glean them from leaves and branches, or pilfer them from the webs of inattentive spiders. Gnatcatchers will also steal the spider’s web for nest building.

Both the male and the female gnatcatcher cooperate in building their little 2-3 inch-wide cup-like nest. The main structural layer of the nest is made with plant stems, bark strips, and grasses which are all held together, and attached to a branch or the crotch of a tree, using spider webs or caterpillar silk. The gnatcatchers then line their nest with plant down (like the seed heads of dandelions), paper, feathers, cocoons or hair. The outside of the nest is covered with more spider webs or caterpillar silk, and then decorated with bits of lichen or flakes of bark. When finished, the nest is so well camouflaged it can be mistaken for a knot on the limb where it rests.

Once the blue-gray gnatcatchers have set up housekeeping, their eggs and nestlings are quite susceptible to hungry thieves like blue jays, woodpeckers, crows, grackles, raccoons, squirrels, chipmunks, and snakes. The gnatcatchers are also susceptible to brood parasitism from brown-headed cowbirds.

Brown-headed cowbirds never build a nest of their own! Instead, they lay their eggs in the nests of other birds and expect them to raise their offspring! If the nest chosen by the cowbird already has eggs, the female cowbird will sometimes eat one of those eggs or push it out of the nest when she leaves an egg of her own! The tiny gnatcatcher parents are unable to eject or puncture this unfamiliar egg, and will try to raise the baby cowbird as their own. This avian interloper, however, will quickly become much larger than its nest mates and much larger than its adoptive parents! The cowbird chick will ultimately crowd out the other hatchlings, and out-compete them for food.

Blue-gray gnatcatchers are not common backyard birds and they do not typically visit bird feeders, but you can encourage them to come to your yard by providing bird-friendly landscaping. They depend on mature, deciduous trees like oaks and maples for nesting, and on a variety of other trees like Eastern hemlock, American birch, American beech, hickory, ash, and wild cherry for the type of insects they attract.

Hopefully, you’ll be lucky enough to see or hear one of these delightful little birds in your own backyard!