AUDIOGRAM OF THE FOX SQUIRREL (SCIURUS-NIGER)

The behavioral audiograms of 2 fox squirrels (Sciurus niger) were dete rmined with a conditioned avoidance procedure. The squirrels were able to hear tones ranging from 113 Hz to 49 kHz at a level of 60 dB sound -pressure level or less, with their best sensitivity of 1 dB occurring at 8 kHz. Their ability to hear frequencies below 150 Hz indicates th at they have good low-frequency hearing, as do the 2 other members of the squirrel family (black-tailed and white-tailed prairie dogs) for w hich audiograms are available. This suggests that the ancestral sciuri d may also have had good low-frequency hearing.