TY - JOUR
T1 - Geographic variations in underwater male Weddell seal Trills suggest breeding area fidelity
AU - Terhune, John M.
AU - Quin, Douglas
AU - Dell'Apa, Andrea
AU - Mirhaj, Mandana
AU - Plötz, Joachim
AU - Kindermann, Lars
AU - Bornemann, Horst
PY - 2008/5/1
Y1 - 2008/5/1
N2 - 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 vocalizations would exhibit clinal patterns. Underwater Trill vocalizations 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 defense 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 >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.
AB - 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 vocalizations would exhibit clinal patterns. Underwater Trill vocalizations 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 defense 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 >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.
KW - Geographic variation
KW - Leptonychotes weddellii
KW - Reproduction
KW - Site fidelity
KW - Underwater vocalizations
KW - Weddell seal
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U2 - 10.1007/s00300-008-0405-4
DO - 10.1007/s00300-008-0405-4
M3 - Article
AN - SCOPUS:42249108156
VL - 31
SP - 671
EP - 680
JO - Polar Biology
JF - Polar Biology
SN - 0722-4060
IS - 6
ER -