Squirrels use birds as alarms
Is it safe? When a squirrel wants to know, it listens to the birds. If the birds are happy, the squirrel will chill.
[A]fter hearing a recorded hawk call, squirrels that subsequently heard the normal chatter of familiar bird species displayed fewer vigilance behaviors, such as freezing or looking up, than did squirrels that heard bird-free ambient noise.
The next step for the Oberlin researchers who figured this out: Do squirrels know which birds are local, and does that make a difference? And can they get other info from listening to birds?
All that will have to wait till the campus opens again — whenever that is.