The starlings are not accustomed to conditions where cleaning out the nest does not result in a cleaned out nest. It is rare that someone or something would keep refilling the nest. That may be why there is not a "turnoff" switch.

This reminds me of a story. I was representing a rancher in a long and expensive trial. He complained one day, after 14 months of large bills, that when he hired a man to build a fence, he paid him once and expected the fence to not require further investment. I reminded him that fence-builders are not followed around by people tearing the fence back down again and again, whereas litigators are indeed opposed by people trying to tear down all that we try to build.

My client, like the starling, just didn't have that turn-off switch; he did not expect that forces of nature or otherwise would conspire to deprive him of the finality of his work, for which he paid so dearly.

RT Cox
Gillette, Wyoming
birder at vcn.com