Dear MARMAM Community
On behalf of my co-authors, I am happy to announce the recent publication of our work:
Shabangu,
F.W., Hlati K., van den Berg M.A., Lamont T., and Kirkman S.P. 2025. “Monthly and Diel Acoustic Occurrence of Four Baleen Whale Species in South African Waters.” Ecology and Evolution 15, no. 8: e72004. https://doi.org/10.1002/ece3.72004
Abstract
Understanding of the spatio-temporal occurrence of cetaceans post the
whaling era is essential for protecting and improving management
strategies of these marine mammals. To determine the monthly and diel
acoustic occurrence of four baleen whale species relative to
environmental conditions off the west coast of South Africa, we
collected passive acoustic monitoring data within Child's Bank marine
protected area in January and May through October 2024 at various water
depths. Burst tonal calls of the southern African Bryde's whale offshore
population were detected in January and May through July with the
highest occurrence in January. Humpback whale songs and southern right
whale gunshot sounds were detected from May through October with high
occurrence in September and with smaller modes in other months.
Antarctic minke whale bioduck calls were also found in June through
October, showing high occurrence in August through October. Calls from
an unknown source with similar characteristics to Antarctic minke whale
bioduck calls were present in May, July, and August with the highest
occurrence in August. Diel acoustic occurrence of Bryde's, southern
right, Antarctic minke, and minke-like whale calls indicated that these
animals vocalised more during the day while humpback whales were more
vocally active at night. Sea surface height and sea surface temperature,
either separately or in combination, were the most important predictors
of whale acoustic occurrence, highlighting the influence of
environmental conditions on the distribution, habitat selection, and
ecology of these whales. Overall, this study advances our understanding
of the movement, occurrence, and behavioural patterns of several baleen
whales relative to environmental conditions. It also provides the first
description of the southern African Bryde's whale offshore population's
call characteristics, which will be useful at guiding future studies to
acoustically differentiate between it and the inshore population.
Best,
Fannie
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Fannie W. Shabangu, PhD (He/Him/His)
Marine Biologist
Department of Forestry, Fisheries and the Environment
Cape Town, South Africa
Mobile: +27 74 220 0210
Tel: +27 21 402 3553
Research Fellow
Mammal Research Institute
Whale Unit
University of Pretoria
Hatfield, South Africa