Variation in hearing within a wild population of beluga whales ( Delphinapterus leuca s)

Documenting hearing abilities is vital to understanding a species' acoustic ecology and for predicting the impacts of increasing anthropogenic noise. Cetaceans use sound for essential biological functions such as foraging, navigation and communication; hearing is considered to be their primary sensory modality. Yet, we know little regarding the hearing of most, if not all, cetacean populations, which limits our understanding of their sensory ecology, population level variability and the potential impacts of increasing anthropogenic noise. We obtained audiograms (5.6-150 kHz) of 26 wild beluga whales to measure hearing thresholds during capture-release events in Bristol Bay, AK, USA, using auditory evoked potential methods. The goal was to establish the baseline population audiogram, incidences of hearing loss and general variability in wild beluga whales. In general, belugas showed sensitive hearing with low thresholds (