Obtaining Underwater Hearing Data for the Common Murre (Uria aalge)

Many species of seabirds dive to great depths and for prolonged intervals in pursuit of food, and they may therefore be affected by anthropogenic underwater noise. The paucity of seabird hearing data precludes the current understanding of noise impacts and limits the abilities to enact with informed mitigation efforts. One interesting family of birds in this respect is the auks (Alcidae). A previous study showed that common murres, Uria aalge, react to underwater sound, but no underwater hearing thresholds have so far been derived from any auk species. Here the underwater hearing abilities of a male common murre were measured using psychophysical methods. The results indicate that common murres, a deep diving seabird, respond to underwater sound at a received level of 130 dB re 1 μPa, underscoring the potential that this species, and perhaps other auks, may be affected by man-made underwater noise.