Michael Zerr, a birder in Sioux Falls, S.D., has made some interesting observations about feeder birds. I got them from a post on the South Dakota birder email list.
He lost a junco to a hawk recently, either a Cooper’s or a Sharpshin, he wrote. Your feeders perhaps have been visited by one of those birds. We get periodic visits from Cooper’s hawks. The birds at our feeders know immediately, maybe sooner, if the hawk is here. Woodpeckers often freeze in place. Other species disappear. It can take the birds as many as 30 minutes to feel safe enough to return.
Zerr points out that his birds know the enemy, lbut show no reaction to the neighborhood Red-tailed Hawk. That species as a rule does not eat songbirds. It’s a hunter of small mammals. Songbirds recognize the difference.
He also has a black squirrel occasionally foraging beneath his feeders. He notes that the birds don’t react differently than they do when his usual fox squirrel is present. His birds also did not react with concern when a muskrat came to eat fallen seed.
He has had a mink invade his flicker nest box. He believes the feeder birds would flee if the mink approached.
A friend lost a junco to a Cooper’s Hawk recently. The junco, fleeing the hawk, flew into the reflections on a storm door. The bird was dead when it hit the step. The hawk carried its meal into the backyard, where it ate, then left this evidence.