Q: I never did really understand “smog.” and what it meant. We don’t hear much about it anymore. As simply as you can put it, explain what smog is. Is the world cured of smog?

— Fred, Pittsfield

A: Don’t we wish! Think China and come up with probably the single worst smog culprit today. Of course, if it was not for economies like ours, driven by the cheapest prices for goods, it probably wouldn’t have gotten as bad. Smog is a term freely given to a combination of smoke and fog, hence smog. Add to that tiny particulates (dust) , and it shows itself as haze, often yellow-brown haze.

Two summers ago we were driving “The Five” (as Southern Californians call Route 5) north from San Diego toward Los Angeles, ultimately arriving at Palm Springs. As we got nearer to L.A., there was a sickly yellowish cast to the skyline. Smog!

Q: I think it is too early to put out the bird feeder as we don’t want the birds that are supposed to go South to stay here too long. When do you suggest is a good time?

— Marie, Lanesborough

A: Discounting bears, which we shouldn’t, it is still early in the season, but if you have never had a problem with bears, with little likelihood of a problem, anytime now is fine. If you want my suggestion, wait until mid- to late October, if there is no chance a bear will not run across it during its rambles.


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If bears have been a problem in the past, wait until after Christmas, if you must put up a feeder. Bird feeders will not delay birds leaving when instinct says “go.”

Q: On our oak trees we have growths. One is of several fuzzy-looking, tan-colored things, some with multiple sections and approximately the size of a pencil eraser or dime. They are not on all leaves, but we are finding them on upper parts of the small trees. Could this be a cocoon of some sort? The trees are doing so good and we are afraid of losing them.

— Shirley, Cheshire

A: These are called oak tree galls.

They are caused by insects, bacteria, mites, viruses, and other things, and most do not cause long term damage to an established tree or shrub.

Questions and comments for Thom Smith: Email Naturewatch@live.com