The jays were regularly fed in this manner. Soon I noticed that only one of the two birds pulled up the bucket, though the other also fed from it. In effect one was depending on the work of the other. After this had gone on for a month, I wondered if the second jay, which had never done any of the work, would be able to pull up the bucket if left alone. Certainly it had had lots of opportunity to learn by seeing its cage mate go through the motion. So I left it alone in the cage. This second jay, despite its chances to learn by observation, took one day longer to learn how to pull up the bucket of food than had the first jay. The jays certainly learned the trick quickly through a trial-and-error process, but simply watching the process seemed to be of little help in learning it. CAN BIRDS COUNT? [Illustration] If birds can count, it's a rather rudimentary thing--perhaps no more than impressions of the size of groups. The widely known example showing that birds don't seem to distinguish between one and two persons is the ruse used by bird photographers and students of birds who are using blinds from which to watch the birds at close range. The hide, or blind, is a little hut built perhaps a few feet from the nest to be photographed. If the photographer enters the blind in the sight of the parent birds, and conceals himself there, the birds who saw him go in will be a long time in coming to the nest and in resuming their normal activities. But if the photographer takes a companion with him, both go into the blind and conceal themselves, and then one of them goes away leaving the other concealed, the bird quickly disregards the intrusion and goes about its activities as though no one were left in the blind. This subterfuge has long been used and is very successful. Apparently the bird is unable to distinguish between the two people that arrive at the nest and the one only that leaves, and behaves as if both had gone away. In my duck-hunting days a duck hunter who used wooden decoys told me he was sure that there was a certain number of decoys necessary before they were effective. The decoys were wooden blocks, carved and painted to resemble life-sized ducks, weighted to float like them, and anchored in shallow water in a flock within gunshot range of the blind in which the duck shooter sat. The idea was that ducks flying by would see the flock on the water, assume that here was a safe resting place, and fly in and light, or attempt to light among them, giving the wild-fowl gunner an opportunity to shoot the wild birds.