At its simplest, a "scarecrow" is any kind of scheme a farmer will use to shoo birds away from eating the crops. We've come to know scarecrows as an effigy of a human, made with clothing and stuffed with straw. That's the cheapest form of scarecrow, but it isn't very effective. Some birds are pretty smart, and even dumb birds will figure out in a few days that a motionless effigy won't hurt them.
Scarecrows of this type have always been common, and tend to look creepy. We aren't built to see a motionless human shape hanging from a pole. Often, scarecrows were designed to look like a monster, as if that would be more terrifying for birds. But scaring birds wasn't always so straightforward. In different times and places, scarecrows were thought of more as a talisman or a good luck charm, urging the powers that be to protect this crop.
So why are scarecrows associated with autumn? It may be that suburbanites and city dwellers never think of farms and crops until the harvest bounty comes in, or it may have to do with the ritual of burning a scarecrow in autumn as part of cleaning up the farm. Read everything you ever needed to know about scarecrows at Popular Science. -via Strange Company
(Image credit: Mohsen H.Rahimi)