Researchers have employed advanced imaging techniques to better understand the auditory sensitivity of Australian Little Penguins and the threats posed by marine noise pollution. This study focuses on how these penguins, also referred to as fairy penguins, hear sounds both in the air and underwater.
Researchers have employed advanced imaging techniques to better understand the auditory sensitivity of Australian Little Penguins and the threats posed by marine noise pollution.
Funded by the Westport program of the Western Australian Marine Science Institution, this study is the first to examine how Little Penguins, known as fairy penguins, detect sound both above and below the water’s surface.
Dr. Chong Wei, who leads the study at Curtin’s Centre for Marine Science and Technology, noted that Little Penguins are especially at risk from human-induced noises, as their natural environments frequently overlap with shipping routes, recreational activities, and coastal developments.
“The level of ocean noise pollution is continually rising, which is particularly troubling for Little Penguins, whose numbers are sharply declining,” Dr. Wei explained.
“Our understanding of how this noise affects penguin hearing is quite limited. To gain insights, we constructed 3D digital models using microCT scans of the skulls of three Little Penguins that had died from natural causes on Garden Island. This allowed us to simulate their hearing across various frequencies.
“Frequencies are measured in hertz (Hz), and our 3D models indicated that Little Penguins are capable of hearing sounds in a wide range between 200 and 6,000 Hz underwater, which is comparable to other diving birds like the Great Cormorant.
“Noise from vessels typically falls within the range of 20 to 10,000 Hz, which is also true for sounds produced during pile driving.”
Co-author John Curtin Distinguished Professor Christine Erbe, who is also affiliated with Curtin’s Centre for Marine Science and Technology, stated that the results of this study are crucial for marine conservation efforts.
“Prolonged exposure to elevated noise levels from passing boats and coastal construction could heighten stress levels and disrupt essential behaviors in Little Penguins, such as feeding,” Professor Erbe noted.
“By understanding their hearing capabilities, we can pinpoint potentially dangerous noise frequencies. These findings will aid in developing management strategies aimed at mitigating the effects of noise pollution.”
The research, titled “Sound reception and hearing capabilities in the Little Penguin (Eudyptula minor): first predicted in-air and underwater audiograms,” has been published in the journal Royal Society Open Science and is available for viewing here.
