The Development of Diving Capabilities in Weddell seal (Leptonychotes weddellii) Pups Throughout Early Ontogeny

2019 ◽  
Author(s):  
Emma Weitzner
Keyword(s):  
Weddell Seal ◽  
Early Ontogeny ◽  
Leptonychotes Weddellii

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

scholarly journals The cephalopod prey of the Weddell seal, Leptonychotes weddellii, a biological sampler of the Antarctic marine ecosystem

Polar Biology ◽  
2015 ◽  
Vol 39 (3) ◽  
pp. 561-564 ◽  
Author(s):  
A. Negri ◽  
G. A. Daneri ◽  
F. Ceia ◽  
R. Vieira ◽  
Y. Cherel ◽  
...  
Keyword(s):  
Marine Ecosystem ◽  
Weddell Seal ◽  
Leptonychotes Weddellii ◽  
Antarctic Marine ◽  
The Antarctic

scholarly journals New data on Weddell seal (Leptonychotes weddellii) colonies: A genetic analysis of a top predator from the Ross Sea, Antarctica

PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0182922 ◽  
Author(s):  
Ighor Antunes Zappes ◽  
Anna Fabiani ◽  
Valerio Sbordoni ◽  
Arnold Rakaj ◽  
Roberto Palozzi ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Ross Sea ◽  
Weddell Seal ◽  
Top Predator ◽  
Leptonychotes Weddellii

scholarly journals An assessment of the audibility of sound from human transport by breeding Weddell seals (Leptonychotes weddellii)

2006 ◽  
Vol 33 (4) ◽  
pp. 275 ◽  
Author(s):  
Tamara D. van Polanen Petel ◽  
John M. Terhune ◽  
Mark A. Hindell ◽  
Melissa A. Giese
Keyword(s):  
Detection Threshold ◽  
Weddell Seal ◽  
Anthropogenic Noise ◽  
Noise Levels ◽  
Leptonychotes Weddellii ◽  
Vehicle Noise ◽  
Weddell Seals ◽  
Vocal Behaviour ◽  
Pedestrian Travel ◽  
Low Amplitude

Anthropogenic noise generated through travel in the Antarctic has the potential to affect the region’s wildlife. Weddell seals (Leptonychotes weddellii) in particular can be exposed to anthropogenic noise because they live under, and breed on, the fast ice on which humans travel. To investigate the potential effects of anthropogenic noise on Weddell seals we developed sound profiles for pedestrian travel, over-snow vehicles, aircraft and watercraft operating at various distances and altitudes from breeding seals. The received 1/3-octave noise levels were then related to an assumed detection threshold for the Weddell seal. We found that most noise levels generated by the pedestrian, quad (4-wheeled, all-terrain vehicle) and Hagglunds (tracked, all-terrain vehicle) were commonly categorised in the inaudible and barely audible range of detection (both in-air and underwater), while noise levels generated by the helicopter, Twin Otter aircraft and Zodiac boat were categorised more commonly in the barely audible and clearly audible range. Experimental underwater recordings of vocal behaviour of Weddell seals exposed to continuous low-amplitude over-snow vehicle noise (i.e. Hagglund operation) were also made. Weddell seals underwater did not alter individual call types in response to low-level Hagglunds noise, but they did decrease their calling rate.

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