Microgeographic variation and songs in the underwater vocalisation repertoire of the Weddell seal (Leptonychotes weddellii) from the Vestfold Hills, Antarctica

Polar Biology ◽  
1994 ◽  
Vol 14 (7) ◽  
Author(s):  
M.G. Morrice ◽  
H.R. Burton ◽  
K. Green
Keyword(s):  
Weddell Seal ◽  
Leptonychotes Weddellii ◽  
Microgeographic Variation ◽  
Vestfold Hills

Repertoire and Geographic Variation in Underwater Vocalisations of Weddell Seals (Leptonychotes weddellii, Pinnipedia : Phocidae) at the Vestfold Hills, Antarctica

1997 ◽  
Vol 45 (2) ◽  
pp. 171 ◽  
Author(s):  
B. C. Pahl ◽  
J. M. Terhune ◽  
H. R. Burton
Keyword(s):  
Weddell Seal ◽  
Recording Site ◽  
Leptonychotes Weddellii ◽  
Breeding Sites ◽  
Analysis Techniques ◽  
Weddell Seals ◽  
Larsemann Hills ◽  
Vestfold Hills ◽  
Study Sites ◽  
Hills Area

The underwater vocalisations of Weddell seals (Leptonychotes weddellii) near Davis, Antarctica, were many and varied. A total of 11029 vocalisations recorded throughout and immediately after the breeding season were analysed. Vocalisations were classified by cluster analysis techniques, based on differences in frequency, duration, call shape, waveform and number of elements. Thirteen broad call categories (many with subdivisions) were identified. Twelve call types (belonging to nine categories) made up 91· 9% of the vocalisations and were present at all seven study sites within the Vestfold Hills, and a single site at the Larsemann Hills approximately 150 km away. A further eight call types (five categories) made up another 6·7% of the vocalisations. These were not detected at every recording site. An additional 29 call types (11 categories) were infrequent and probably reflect the diversity of individual seals. This study strengthens the case for macrogeographic variation in underwater Weddell seal vocalisations around Antarctica. Microgeographic differences, between sites within 150 km, were weak and not consistent between sites or years. Some adult females move to different breeding sites within the Vestfold Hills area between years. This would probably preclude the establishment of site-specific (microgeographic) repertoire differences.

Calling depth and time and frequency attributes of harp (Pagophilus groenlandicus) and Weddell (Leptonychotes weddellii) seal underwater vocalizations

2005 ◽  
Vol 83 (11) ◽  
pp. 1438-1452 ◽  
Author(s):  
Hilary B Moors ◽  
John M Terhune
Keyword(s):  
Light Condition ◽  
Weddell Seal ◽  
Harp Seal ◽  
Vertical Array ◽  
Vocal Cords ◽  
Leptonychotes Weddellii ◽  
Call Duration ◽  
Weddell Seals ◽  
Pagophilus Groenlandicus ◽  
Breeding Seasons

Harp seal (Pagophilus groenlandicus (Erxleben, 1777)) daytime calling depth during the breeding season and Weddell seal (Leptonychotes weddellii (Lesson, 1826)) daytime and nighttime calling depth during the winter and breeding seasons were investigated using a small vertical array with hydrophones placed at depths of 10 and 60 m. Rough calling depth estimates (<35 m, ~35 m, >35 m) and more accurate point depth estimates (±5–10 m in most cases) were obtained. Significantly more calls were produced at depths ≤35 m for both species. The point depth estimates indicated that the calls occurred most frequently at depths >10 m; 60% of harp seal calls and 71% of Weddell seal calls occurred at depths between 10 and 35 m. The seals called predominately within areas of the water column where light would likely penetrate, but still avoided sea-ice interference to some extent. The vocalizations did not change over depth with respect to call type, the number of elements within a call, or total call duration, or with respect to season and light condition for Weddell seals. Frequency (kHz) of calls also did not change with depth, suggesting that harp and Weddell seals control the pitch of their vocalizations with the vocal cords of the larynx.

Perfluoroalkyl substances detected in the world's southernmost marine mammal, the Weddell seal ( Leptonychotes weddellii )

2015 ◽  
Vol 197 ◽  
pp. 62-67 ◽  
Author(s):  
Heli Routti ◽  
Bjørn A. Krafft ◽  
Dorte Herzke ◽  
Regina Eisert ◽  
Olav Oftedal
Keyword(s):  
Marine Mammal ◽  
Weddell Seal ◽  
Perfluoroalkyl Substances ◽  
Leptonychotes Weddellii

Preweaning mortality of Weddell seal pups

1996 ◽  
Vol 74 (9) ◽  
pp. 1775-1778 ◽  
Author(s):  
Jason F. Schreer ◽  
Kelly K. Hastings ◽  
J. Ward Testa
Keyword(s):  
Mortality Rates ◽  
Weddell Seal ◽  
Leptonychotes Weddellii ◽  
Mark Recapture ◽  
Mcmurdo Sound ◽  
Weddell Seals ◽  
Ice Surface ◽  
Open Populations ◽  
Significant Mortality

We examined mortality prior to weaning of Weddell seal pups (Leptonychotes weddellii), using resighting data collected from 1984 to 1993 on the annual ice of McMurdo Sound, Antarctica. Mortality rates were estimated using counts of dead pups found on the surface and mark–recapture techniques. The standard Jolly–Seber model for open populations fit the recapture data best and corresponded well to the known biology of these animals. Yearly mortality rates estimated by mark–recapture techniques ranged from 6 to 22%, with a mean across years of 13%. These values are twice as high as those previously reported for Weddell seals and those calculated from counts of dead pups in this study. This suggests that there is significant unseen mortality due either to undiscovered fatalities on the ice surface or to significant mortality occurring in the water.

Apparent twin pups of the Weddell seal Leptonychotes weddellii (Carnivora: Phocidae) near Mawson, Antarctica.

2003 ◽  
Vol 25 (2) ◽  
pp. 197
Author(s):  
P Shaughnessy ◽  
E Erb
Keyword(s):  
Adult Female ◽  
Weddell Seal ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Field Observations ◽  
Mirounga Leonina ◽  
Leptonychotes Weddellii ◽  
Pinniped Species ◽  
Phocid Seals ◽  
Made In

PHOCID seals give birth annually, generally to a single pup. Twins have been reported occasionally, either from observations made in utero or from observations of live pups in the field. Examples of the former are reports of two embryos in a Weddell seal, Leptonychotes weddellii (Bertram 1940) and of twin foetuses of a southern elephant seal, Mirounga leonina (Bryden 1966). Observations of two pups suckling one adult female have been reported for L. weddellii (e.g., Gelatt et al. 2001). For M. leonina, Carrick et al. (1962) reported an adult female that expelled two placentae and gave birth to a pup while another newborn pup was nuzzling the female. The occurrence of twin pups in several pinniped species is reviewed by Spotte (1982). Here we use the expression 'apparent twins' to refer to reports of twin L. weddellii pups that are based solely on field observations of two pups with the same adult female on several occasions.

Variation of Weddell seal (Leptonychotes weddellii) underwater vocalizations over mesogeographic ranges

2003 ◽  
Vol 29 (2) ◽  
pp. 268-277 ◽  
Author(s):  
Patrick Abgrall ◽  
John M. Terhune ◽  
Harry R. Burton
Keyword(s):  
Weddell Seal ◽  
Leptonychotes Weddellii
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