Dear colleagues,
On behalf of my coauthors, I am excited to share our recent open-access publication in Royal Society Open Science.
Parnell K, Smith C, Diaz A, Fertitta K, Thompson P, Patton PT, Charrier I, Robinson SJ, Pacini A, Bejder L. 2025 Underwater sound production of free-ranging Hawaiian monk seals. R. Soc. Open Sci. 12: 250987.
https://doi.org/10.1098/rsos.250987
Abstract:
Hawaiian monk seals (HMS; Neomonachus schauinslandi) are endemic and endangered
with a population of ~1,600 individuals. While research has provided extensive
information on HMS biology, movements, and population ecology, its underwater
vocal behavior remains largely undocumented,
with previous descriptions limited to two individuals in human-care. To broaden
our understanding of sound production in free-ranging seals, we deployed
passive acoustic recorders at five sites across the Hawaiian Archipelago. From
>4,500 hours of
recordings, we manually detected and classified >23,000 underwater
vocalizations. A discriminant function analysis of 10 call types yielded an average correct classification rate of 63%. We identified 25 call types, including five
published elemental calls and 20 novel calls. Nineteen of the novel call types
were combinational calls—an undocumented communication strategy in pinnipeds.
The novel Whine, captured via
biologging tag- and citizen-scientist videos, provided a rare example of
context-specific call use in pinnipeds. Vocalizations
were low-frequency (<1 kHz), short-medium duration (<7 sec), with 66%
occurring in bouts. Calls were detected
throughout the day at three of five sites, with peaks at night and late
afternoon. These findings establish a baseline for
HMS vocal behavior and emphasize the importance of acoustic communication in
future research and conservation efforts.
Cheers,
Kirby Parnell
--
Kirby Parnell, M.Sc.
(Citizen, Cherokee Nation/ᏣᎳᎩᎯ ᎠᏰᎵ; she/her)
Ph.D. Candidate, Marine Biology Graduate Program
Marine Mammal Research Program
University of Hawaiʻi Mānoa