Geographic variations in underwater male Weddell seal Trills suggest breeding area fidelityEntry ID: ASAC_1132-2
Abstract: Adult Weddell seals (Leptonychotes weddellii) exhibit site fidelity to where they first breed but juveniles, and perhaps transient adult males, may disperse from their natal location. If there is mixing between adjacent breeding
groups, we would expect that common vocalisations would exhibit clinal patterns. Underwater Trill vocalisations of male Weddell seals at Mawson, Davis, Casey, ... McMurdo Sound, Neumayer and Drescher Inlet separated by ca. 500
to >9,000 km, were examined for evidence of clinal variation. Trills are only emitted by males and have a known territorial defence function. Trills from Davis and Mawson, ca. 630 km apart, were distinct from each other and exhibited
the greatest number of unique frequency contour patterns.
The acoustic features (duration, waveform, frequency contour) of Trills from Neumayer and Drescher Inlet, ca. 500 km apart, were more distinct from each other than they were from the other four locations. General Discriminant
Analysis and Classification Tree Analysis correctly classified 65.8 and 76.9% of the Trills to the correct location. The classification errors assigned more locations to sites greater than 630 km away than to nearest neighbours. Weddell seal Trills exhibit geographic variation but there is no evidence of a clinal pattern. This suggests that males remain close to single breeding areas throughout their lifetime.
This work was completed as part of ASAC project 1132 and 2122 (ASAC_1132, ASAC_2122).
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Data Set Citation
Dataset Originator/Creator: John Terhune
Dataset Title: ASAC_1132-2
Dataset Series Name: Weddell seal Trill geographic variation
Dataset Release Date: July 16, 2008
Data Presentation Form: Excel file
Start Date: 1991-10-01Stop Date: 2006-12-31
Quality The data are measurements relating to the acoustic properties of Weddell seal underwater Trill vocalisations. The measures include a broad classification of the waveform (sinusoidal, frequency modulated or pulsed)at the start and end of the Trill, the duration (milliseconds) and the frequency (Hz) at the beginning, end and at 9 other equally spaced intervals along the call. Trills were recorded in different years from 6 locations around Antarctica. Only Trill vocalisations were analysed because they are only made by males and they have a known territorial defence function.
Access Constraints These data are publicly available for download from the provided URLs.
Use Constraints This data set conforms to the PICCCBY Attribution License
The investigators and technical contacts must be credited when using these data. The names and addresses of the investigators are listed in the Polar Biology publication attached below (Polar Biology, 2008, 31: 671-680).
Please follow instructions listed in the citation reference at the provided URL when using these data.
Data Set Progress
Distribution Media: HTTP
Distribution Size: 31 kb
Distribution Format: excel
Distribution Media: HTTP
Distribution Size: 395 kb
Distribution Format: pdf
Role: TECHNICAL CONTACT
Role: DIF AUTHOR
Phone: +1 506 648 5633
Fax: +1 506 648 5811
Email: terhune at unbsj.ca
Department of Biology PO Box 5050 University of New Brunswick
City: Saint John
Province or State: New Brunswick
Postal Code: E2L 4L5
Terhune, J.M., Quin, D., Dell'Apa, A., Mirhaj, M., Plotz, J., Kindermann, L. and Bornemann, H. 2008. Geographic variations in underwater male Weddell seal Trills suggest breeding area fidelity. Polar Biology 31: 671-680.
Creation and Review Dates
DIF Creation Date: 2008-07-16
Last DIF Revision Date: 2010-07-26