What kind of squirrel call was this?

I heard a squirrel make alarm call repeatedly, and it was later caught and eaten by a red-tailed hawk. Alarm calls are usually high pitched, and short in duration, whether it is made by a squirrel or a bird. That is the way evolution has shaped alarm calls. It is meant to alert other animals, even those of a different species. The purpose is to make it more difficult for a predator to concentrate on a single individual. The squirrel I saw making that alarm call don't seem to know that it is not supposed to stand there and keep making alarm calls. As a result, any animal that should have fled have already done so, and means it is the only one still around. When it keeps repeating the alarm call, it allows the hawk to zero in on the caller. This is natural selection at work. Those animals that act in a way that is not adaptive will be eliminated from the gene pool. The survivors are not likely to carry the same maladaptive genes found in this squirrel. Of course, the squirrel may not have bad genes. Something could have gone wrong with its brain or body and it as a result acted in a stupid way. Regardless, its behavior made it less likely to survive and reproduce than other individuals of the same species.

Easy. He was crossing the road with his family. He went first to make sure the coast was clear. Once he was across, he made that call to signal to the rest of his family that it is safe to cross.