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Drier weather may mean fewer gnats and fewer gnat-eating birds

An Anna's hummingbird feeding on a swarm of gnats.
An Anna's hummingbird feeding on a swarm of gnats.
Darlene Luckins

One may have noticed that there are fewer clouds of gnats flying around outdoors lately. That might be due to the lack of moisture in the air. Some people may think this is good news because gnats have been a huge problem in San Diego for the last few years and are now considered a "vector". They thrive in hot dry areas with watered lawns and crops and are often present around organic farms because of the plowed fields and ample moisture. But, the lack of gnats is not necessarily the best thing for the birds that rely on gnats and similar insects for food.

The most common types of outdoor gnats in San Diego County are eye gnats. They are called “eye gnats” because they often fly in around animal’s eyes, nose and mouths looking for mucus as an extra source of protein for breeding. They can be seen flying around in huge clouds when temperature and moisture is high. There are over 2000 species of eye gnats and not all species are annoying pests, but many are. Some eye gnats are aggressive and bite, some do not. The other types of gnat in the county are fungus gnats which feed on mold and fungus around over-watered plants. These are the types that one usually sees indoors.

Birds that thrive on gnats are birds that catch insects on the wing. Swallows, especially, scoop up bellies-full of gnats as they swiftly fly around. This year, fewer swallows have been seen flying around in some areas, such as Lake Murray, where large concentrations of gnats are common this time of year. Other birds that benefit from gnats are flycatchers such as phoebes, hummingbirds and kingbirds, and, of course, gnatcatchers.

If the weather remains dry, there will likely be fewer gnats to annoy animals and people or cause other problems. But, that might mean fewer sightings, in some areas, of insect eating birds that many people enjoy watching. Unfortunately, if these birds leave the area because of the lack of insects, and the gnats increase, they will be a bigger problem. At least until the birds discover them in their old areas again and return.