[MARMAM] New publication: Sperm whales clicking throughout the year
fannie.shabangu at yahoo.com
Thu Dec 17 10:44:50 PST 2020
My co-author and I are pleased to announce the publication of our new paper published in Endangered Species Research.
Shabangu FW, Andrew RK (2020) Clicking throughout the year: sperm whale clicks in relation to environmental conditions off the west coast of South Africa. Endang Species Res 43:475-494. https://doi.org/10.3354/esr01089
Knowledge of cetacean occurrence and behaviour in southern African waters is limited, and passive acoustic monitoring has the potential to address this gap efficiently. Seasonal acoustic occurrence and diel-vocalizing patterns of sperm whales in relation to environmental conditions are described here using passive acoustic monitoring data collected off the west coast of South Africa. Four autonomous acoustic recorders (AARs) were deployed on 3 oceanographic moorings from July 2014 to January 2017. Sperm whale clicks were detected year round in most recording sites, with peaks in acoustic occurrence in summer and late winter through spring. Diel-vocalizing patterns were detected in winter, spring and summer. Higher percentages of sperm whale clicks were recorded by AARs deployed at 1100 m water depth compared to those concurrently deployed at 850 and 4500 m, likely inferring that the whales exhibited some preference to water depths around 1100 m. Acoustic propagation modelling suggested a maximum detection range of 83 km in winter for sperm whale clicks produced at 1100 m. Random forest models classified daylight regime, sea surface height anomaly and month of the year as the most important predictors of sperm whale acoustic occurrence. The continuous acoustic occurrence of sperm whales suggests that the study area supports large biomasses of prey to sustain this species’ food requirements year round. This is the first study to describe the seasonal acoustic occurrence and diel-vocalizing patterns of sperm whales off the west coast of South Africa, extending knowledge of the species previously available only through whaling records.
The the paper can be downloaded at: https://www.int-res.com/abstracts/esr/v43/p475-494/
Fannie_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Fannie W. Shabangu, PhD
Fisheries Management Branch
Department of Environment, Forestry and Fisheries
Cape Town, South Africa
Email: FannieS at daff.gov.za; fannie.shabangu at yahoo.com Mobile: +27 74 220 0210
Tel: +27 21 402 3553
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