Alarm calls alert receivers to the presence and/or nature of a predatory threat. Studies of alarm communication in
Richardson’s ground squirrels (Spermophilus richardsonii) have focused on juvenile signalers and receivers;
however, adult and juvenile receivers may tailor their response to alarm calls based on different underlying signal
parameters and attend differentially to alarm calls broadcast by adult versus juvenile signalers. To examine the
potential influence of signaler and receiver age on the perception of response urgency, we presented free-living
juvenile and adult S. richardsonii with alarm calls produced by juveniles and adults. Behavioral responses of call
recipients were videotaped and analyzed to determine the influence of signaler and receiver age-class. No
differences in vigilance response after juvenile- and adult-produced calls were detected for either adult or juvenile
receivers. At the proximate level, the absence of any detectable difference in the acoustic attributes of juvenileversus
adult-produced calls may account for the lack of differential response. The absence of any age-dependent
productional difference also is consistent with the recently advanced notion of young concealing information
regarding their age in their alarm signals.