The boy who cries wolf isn’t the only one who loses credibility. Burrowing squirrels known as Richardson’s ground squirrels pay less attention to alarms from a neighbor associated with false signals than to calls from a source with a better record, says James F. Hare of University of Manitoba in Winnipeg.
A group of these ground squirrels shares a tangle of tunnels, and any squirrel that spots a badger, coyote, or other menace gives a call that Hare describes as sounding a lot like “eek.” Hare had accidentally discovered that he could elicit eeks by tossing his hat toward a youngster.
To test whether the ground squirrels heed different alarms more or less, Hare recorded a selection of prompted eeks.
Hare and his colleague Brent A. Atkins then created a reliable alarm by playing eeks from a particular individual while wheeling a stuffed badger toward the colony. To impersonate chronic false alarmers, the researchers played calls recorded from another individual but didn’t present the badger.
By the tenth false alarm, the animals stopped assuming the kind of vigilant behavior associated with genuine threats. The calls linked to the stuffed-badger treatment, however, continued to elicit intense responses even without the badger.
Hare and Atkins report their results in a forthcoming issue of Behavioral Ecology and Sociobiology.