Gentoo penguins (Pygoscelis papua) react to underwater sounds.

K Sørensen,M Dähne,M Wahlberg,K A Hansen,C Neumann

doi:10.1098/rsos.191988

K Sørensen, M Dähne + Show 3 more

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https://doi.org/10.1098/rsos.191988

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Abstract

Marine mammals and diving birds face several physiological challenges under water, affecting their thermoregulation and locomotion as well as their sensory systems. Therefore, marine mammals have modified ears for improved underwater hearing. Underwater hearing in birds has been studied in a few species, but for the record-holding divers, such as penguins, there are no detailed data. We played underwater noise bursts to gentoo penguins (Pygoscelis papua) in a large tank at received sound pressure levels between 100 and 120 dB re 1 µPa RMS. The penguins showed a graded reaction to the noise bursts, ranging from no reactions at 100 dB to strong reactions in more than 60% of the playbacks at 120 dB re 1 µPa. The responses were always directed away from the sound source. The fact that penguins can detect and react to underwater stimuli may indicate that they make use of sound stimuli for orientation and prey detection during dives. Further, it suggests that penguins may be sensitive to anthropogenic noise, like many species of marine mammals.

Highlights

Marine mammals and diving birds are secondarily adapted to the aquatic environment
Results of playbacks on seven adult gentoo penguins are presented in figure 4
All seven gentoo penguins reacted to the underwater noise pulses, and they did so in a graded manner

Summary

Introduction

Marine mammals and diving birds are secondarily adapted to the aquatic environment. Their anatomy and physiology, initially tuned for terrestrial life, have been modified to function in water. Some species can dive to depths of more than 500 m for more than an hour in pursuit of their prey, which include fish, cephalopods and crustaceans. Their bodies are streamlined to reduce drag and preserve body heat while diving. Many species hunt for fish year-around in cold waters while keeping their core body temperature intact [1]. In addition to these adaptations, some of the sensory systems of marine mammals and diving birds have been adjusted to royalsocietypublishing.org/journal/rsos R.

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