erman spent years monitoring these squirrels by tagging ears and marking animals with hair dye to establish family trees for hundreds of ground squirrels in California's Sierra Nevada. Sherman, with the aid of 10 field assistants, then logged more than 3,000 hours watching the ground squirrels and their terrestrial predators. Weasels visited 67 times, badgers 11 times, and other menaces made 24 appearances.
The observations allowed Sherman to analyze the possible benefits an animal might gain from sticking its neck up and squealing (Milius, 1998, p. 175). He examined altruistic behaviors such as whether the ground squirrels' whistles themselves deter the predator, whether they incite the colony members to mob the intruder, or whether they create a ventriloquist effect and misdirect the predator. Another possibility was that when a squirrel squeaks, the others engage in such a flurry of flight that the predator has a host of moving targets to choose from and this distracts them. However, Sherman found no mobbing, pandemonium or ventriloquism among
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