1 October 2023
Fall migration has been intense over Pittsburgh lately and promises to be excellent tonight and tomorrow as well. Yesterday morning I went birding at Frick Park, expecting to find loads of warblers. No such luck. The birds flew over without stopping. However, for chipmunks it was a fantastic day.
Despite the current warm weather, chipmunks (Tamias striatus) are frantically gathering food to store in their underground burrows where they’ll spend the winter. Since they can’t use their paws to carry food, they fill their enormous cheek pouches.
What could possibly make their cheeks so fat? How about acorns?
With so many chipmunks scurrying in autumn, you rarely see two together. Chipmunks are antisocial but they like to make calls to warn each other of predators. Among their most common calls are two kinds of warnings.
Cheep or Chip: “Danger from the ground!” This call sounds almost like a bird and warns of nearby terrestrial predators such as a cat, fox, coyote or raccoon.
Tock or Knock: “Danger from the air! I see a hawk!” This is a useful call for birders that tells us to search for a hawk nearby. However, chipmunks know that hawks fly rapidly through the forest so all of them take up the call, far and wide, even though the hawk is not near them. Tock! Tock! Tock! Where is that hawk? Erf!
Read more about the chipmunk’s calls at North American Nature: What Sounds Does a Chipmunk Make?
(credits are in the captions)