Log in

Relevant bibliographies by topics / Weddell seal Seals (Animals) Seals (Animals) / Journal articles

To see the other types of publications on this topic, follow the link: Weddell seal Seals (Animals) Seals (Animals).

Journal articles on the topic 'Weddell seal Seals (Animals) Seals (Animals)'

Author: Grafiati

Published: 4 June 2021

Last updated: 7 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Weddell seal Seals (Animals) Seals (Animals).'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Gales, NJ, NJ Gales, HR Burton, and HR Burton. "Use of Emetics and Anesthesia for Dietary Assessment of Weddell Seals." Wildlife Research 15, no. 4 (1988): 423. http://dx.doi.org/10.1071/wr9880423.

Full text

Abstract:

One female and 19 male Weddell seals, Leptonychotes weddellii, were injected with the emetic apomorphine hydrochloride. Fourteen of these were immobilised with combinations of ketamine hydrochloride and diazepam before the emetic was injected. One seal was administered the emetic tincture of ipecac while immobilised. The mean induction dose of ketamine hydrochloride was 7.99 � 1.99 mg kg-1 (mean�SD) and that of diazepam was 0.05 � 0.01 mg kg-1. The mean induction time was 23.07 � 17.63 min and the mean duration of immobilisation was 127.00 � 20.72 min. Six of the 22 seals apomorphine hydrochlo

APA, Harvard, Vancouver, ISO, and other styles

2

Hochachka, P. W., and R. A. Foreman III. "Phocid and cetacean blueprints of muscle metabolism." Canadian Journal of Zoology 71, no. 10 (1993): 2089–98. http://dx.doi.org/10.1139/z93-294.

Full text

Abstract:

Large seals, such as northern and southern elephant seals and Weddell seals, are able to dive for unexpected lengths of time and to enormous depth. The current dive-duration record is 120 min (recorded for the southern elephant seal); the current depth record is 1.5 km (recorded for the northern elephant seal). Equally striking is the widespread observation that these seals, when at sea, spend close to 90% of the time submerged and often at great depth. For practical purposes, these species can be viewed as true mesopelagic animals when they are at sea. Analysis of current knowledge indicates

APA, Harvard, Vancouver, ISO, and other styles

3

Wartzok, Douglas, Robert Elsner, Henry Stone, Brendan P. Kelly, and Randall W. Davis. "Under-ice movements and the sensory basis of hole finding by ringed and Weddell seals." Canadian Journal of Zoology 70, no. 9 (1992): 1712–22. http://dx.doi.org/10.1139/z92-238.

Full text

Abstract:

Arctic ringed seals (Phoca hispida) and antarctic Weddell seals (Leptonychotes weddelli) were tracked using an attached acoustic tag during their under-ice movements at isolated experimental sites with varying numbers of novel breathing holes. Both natural and artificial visual landmarks were used by the seals during their dives. Seals deprived of vision through blindfolding greatly restricted their diving. Blindfolded seals responded to supplied acoustic cues and moved toward them. Prior to swimming toward an acoustic cue, the animals often swam at an angle to the direct line to the source of

APA, Harvard, Vancouver, ISO, and other styles

4

Testa, J. Ward. "Juvenile survival and recruitment in a population of Weddell seals (Leptonychotes weddellii) in McMurdo Sound, Antarctica." Canadian Journal of Zoology 65, no. 12 (1987): 2993–97. http://dx.doi.org/10.1139/z87-453.

Full text

Abstract:

Survival and recruitment of Weddell seal pups were studied in eastern McMurdo Sound, Antarctica. Pups were marked and their apparent survival estimated by mark–recapture methods. The resulting estimates were used together with published estimates of adult survival, yearly sighting probabilities, and direct counts of pup production to simulate the dynamics of the population and evaluate the assumption that it is closed to immigration. Estimates derived from census data in 1982 and 1983 were over five times larger than those simulated. This discrepancy was due to the extremely low juvenile survi

APA, Harvard, Vancouver, ISO, and other styles

5

Kooyman, Gerald. "Animal-Borne Instrumentation Systems and the Animals that Bear Them: Then (1939) and Now (2007)." Marine Technology Society Journal 41, no. 4 (2007): 6–8. http://dx.doi.org/10.4031/002533207787441935.

Full text

Abstract:

The history of animal-borne instrumentation is reviewed from the first basic depth gauge invented in the late 1800s, to the complex animal-borne imagery and archival systems of the present day. A major breakthrough occurred in 1964 when the first time-depth recorder was deployed on a Weddell Seal in McMurdo Sound, Antarctica. The next phase in the study of animals at sea was the use of microprocessors as archival recorders in the mid-1980s. These also were first attached to Weddell seals in McMurdo Sound. Microprocessor technology made possible the next major step of attaching a video camera h

APA, Harvard, Vancouver, ISO, and other styles

6

Guppy, M., R. D. Hill, R. C. Schneider, et al. "Microcomputer-assisted metabolic studies of voluntary diving of Weddell seals." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 250, no. 2 (1986): R175—R187. http://dx.doi.org/10.1152/ajpregu.1986.250.2.r175.

Full text

Abstract:

Utilizing a microprocessor-controlled peristaltic withdrawal pump, arterial blood samples were obtained from Weddell seals (Leptonychotes weddelli) while diving voluntarily under the sea ice at McMurdo Sound, Antarctica. Plasma concentrations of glucose, lactate, free fatty acids, urea, and amino acids were determined in seals at various times during rest, diving, and recovery. In addition, radiolabeled palmitate, glucose, lactate, p-aminohippurate, inulin, galactose, and cholate were injected into the descending aorta of seals in the resting state or during voluntary diving at sea. Sequential

APA, Harvard, Vancouver, ISO, and other styles

7

Hindle, Allyson G., Kaitlin N. Allen, Annabelle J. Batten, et al. "Low guanylyl cyclase activity in Weddell seals: implications for peripheral vasoconstriction and perfusion of the brain during diving." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 316, no. 6 (2019): R704—R715. http://dx.doi.org/10.1152/ajpregu.00283.2018.

Full text

Abstract:

Nitric oxide (NO) is a potent vasodilator, which improves perfusion and oxygen delivery during tissue hypoxia in terrestrial animals. The vertebrate dive response involves vasoconstriction in select tissues, which persists despite profound hypoxia. Using tissues collected from Weddell seals at necropsy, we investigated whether vasoconstriction is aided by downregulation of local hypoxia signaling mechanisms. We focused on NO–soluble guanylyl cyclase (GC)-cGMP signaling, a well-known vasodilatory transduction pathway. Seals have a lower GC protein abundance, activity, and capacity to respond to

APA, Harvard, Vancouver, ISO, and other styles

8

Schreer, Jason F., Kelly K. Hastings, and J. Ward Testa. "Preweaning mortality of Weddell seal pups." Canadian Journal of Zoology 74, no. 9 (1996): 1775–78. http://dx.doi.org/10.1139/z96-195.

Full text

Abstract:

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 previous

APA, Harvard, Vancouver, ISO, and other styles

9

Kanatous, S. B., R. W. Davis, R. Watson, L. Polasek, T. M. Williams, and O. Mathieu-Costello. "Aerobic capacities in the skeletal muscles of Weddell seals: key to longer dive durations?" Journal of Experimental Biology 205, no. 23 (2002): 3601–8. http://dx.doi.org/10.1242/jeb.205.23.3601.

Full text

Abstract:

SUMMARYIn contrast to terrestrial animals that function under hypoxic conditions but display the typical exercise response of increasing ventilation and cardiac output, marine mammals exercise under a different form of hypoxic stress. They function for the duration of a dive under progressive asphyxia,which is the combination of increasing hypoxia, hypercapnia and acidosis. Our previous studies on short-duration, shallow divers found marked adaptations in their skeletal muscles, which culminated in enhanced aerobic capacities that are similar to those of atheltic terrestrial mammals. The purpo

APA, Harvard, Vancouver, ISO, and other styles

10

Kooyman, Gerald. "Marine mammals and Emperor penguins: a few applications of the Krogh principle." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 308, no. 2 (2015): R96—R104. http://dx.doi.org/10.1152/ajpregu.00264.2014.

Full text

Abstract:

The diving physiology of aquatic animals at sea began 50 years ago with studies of the Weddell seal. Even today with the advancements in marine recording and tracking technology, only a few species are suitable for investigation. The first experiments were in McMurdo Sound, Antarctica. In this paper are examples of what was learned in Antarctica and elsewhere. Some methods employed relied on willingness of Weddell seals and emperor penguins to dive under sea ice. Diving depth and duration were obtained with a time depth recorder. Some dives were longer than an hour and as deep as 600 m. From a

APA, Harvard, Vancouver, ISO, and other styles

11

Cameron, Michael F., Donald B. Siniff, Kelly M. Proffitt, and Robert A. Garrott. "Site fidelity of Weddell seals: the effects of sex and age." Antarctic Science 19, no. 2 (2007): 149–55. http://dx.doi.org/10.1017/s0954102007000223.

Full text

Abstract:

AbstractSite fidelity is believed to be an important life history strategy for Weddell seals (Leptonychotes weddellii), that return to traditional breeding colonies each spring. We examined four hypotheses concerning their fidelity to these colonies: 1) fidelity is stronger to natal sites (natal fidelity) than to other sites, 2) females exhibit greater site fidelity than males, 3) site fidelity for both sexes increases with age, 4) site fidelity in adult females is related to their reproductive status and their total number of offspring. Analysis of a long-term tagging database from McMurdo So

APA, Harvard, Vancouver, ISO, and other styles

12

Ribic, C. A., D. G. Ainley, and W. R. Fraser. "Habitat selection by marine mammals in the marginal ice zone." Antarctic Science 3, no. 2 (1991): 181–86. http://dx.doi.org/10.1017/s0954102091000214.

Full text

Abstract:

As part of the multi-disciplinary project, Antarctic Marine Ecosystem Research at the Ice Edge Zone (AMERIEZ), habitat selection by marine mammals was investigated within the marginal ice zone in relation to measured ice variables and other environmental factors. Data were collected on three cruises to the southern Scotia and northern Weddell seas during spring 1983, autumn 1986, and winter 1988. During winter, Antarctic fur seals were significantly associated with drift, pancake, brash ice, icebergs, and areas of uneven floe distribution, all characteristic of the marginal ice zone. Fur seals

APA, Harvard, Vancouver, ISO, and other styles

13

Focardi, S., R. Bargagli, and S. Corsolini. "Isomer-specific analysis and toxic potential evaluation of polychlorinated biphenyls in Antarctic fish, seabirds and Weddell seals from Terra Nova Bay (Ross Sea)." Antarctic Science 7, no. 1 (1995): 31–35. http://dx.doi.org/10.1017/s095410209500006x.

Full text

Abstract:

To provide data on the degree of contamination of the marine ecosystem isomer-specific concentrations of polychlorinated biphenyls, including planar, mono- and di-ortho congeners, were measured in the Weddell seal, the Adélie penguin, the south polar skua, and in two species of Antarctic fish (Trematomus bernacchii and Chionodraco hamatus) from Terra Nova Bay, Antarctica. The results show a clear relation between PCB concentrations and trophic level, in the order fish < Adélie penguin < Weddell seal. The higher values found in the skua appear to be related to its migration to more contam

APA, Harvard, Vancouver, ISO, and other styles

14

Cameron, Michael F., and Donald B. Siniff. "Age-specific survival, abundance, and immigration rates of a Weddell seal (Leptonychotes weddellii) population in McMurdo Sound, Antarctica." Canadian Journal of Zoology 82, no. 4 (2004): 601–15. http://dx.doi.org/10.1139/z04-025.

Full text

Abstract:

Since the 1960s, Weddell seals (Leptonychotes weddellii (Lesson, 1826)) have been tagged and surveyed annually in McMurdo Sound, Antarctica. Markrecapture analyses and model selection trials using Akaike's Information Criterion indicate that sex, cohort, and year affect juvenile (ages 1 and 2) survival. In contrast, year and perhaps sex and cohort are less important factors for adult survival. Average annual survival is higher among adults (0.93) than juveniles (0.550.59) and there is little evidence for senescence to at least age 17. The oldest known-aged female and male in the study were 2

APA, Harvard, Vancouver, ISO, and other styles

15

van Polanen Petel, Tamara, Melissa Giese, and Mark Hindell. "A preliminary investigation of the effect of repeated pedestrian approaches to Weddell seals (Leptonychotes weddellii)." Applied Animal Behaviour Science 112, no. 1-2 (2008): 205–11. http://dx.doi.org/10.1016/j.applanim.2007.07.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Khoyetskyy, Pavlo. "The status of the fur seal population (Arctocephalus gazelle) on the southern border of the distribution area (the Argentine Islands archipelago)." Theriologia Ukrainica 2021, no. 21 (2021): 165–73. http://dx.doi.org/10.15407/tu2115.

Full text

Abstract:

The study of the population status of Arctocephalus gazella (Peters, 1875) in waters of the Argentine Islands was carried out in the period from April 2015 to March 2016 in accordance with the objectives of the State Target Scientific and Technical Research Program of Ukraine in Antarctica for 2011–2020. The aim of the article is to study the population dynamics and distribution of the southern fur seal in waters of the Argentine Islands. Due to the lack of data on the specifics of the seal’s dispersal in different periods of the year and the dynamics of the species population at the southern

APA, Harvard, Vancouver, ISO, and other styles

17

Tosh, C. A., H. Bornemann, S. Ramdohr, et al. "Adult male southern elephant seals from King George Island utilize the Weddell Sea." Antarctic Science 21, no. 2 (2008): 113–21. http://dx.doi.org/10.1017/s0954102008001557.

Full text

Abstract:

AbstractAdult male southern elephant seals instrumented in 2000 on King George Island (n = 13), travelled both to the north (n = 2) and to the east (n = 6) of the Antarctic Peninsula. Five males remained within 500 km of the island focusing movements in the Bransfield Strait and around the Antarctic Peninsula. Sea surface temperatures encountered by these animals showed little variation. While animal trajectories appeared unaffected by sea ice cover, areas of shallow depths were frequented. Three males moved as far as 75°S to the east of the Peninsula with maximum distances of more than 1500 k

APA, Harvard, Vancouver, ISO, and other styles

18

Butler, P. J., and D. R. Jones. "Physiology of diving of birds and mammals." Physiological Reviews 77, no. 3 (1997): 837–99. http://dx.doi.org/10.1152/physrev.1997.77.3.837.

Full text

Abstract:

This review concentrates on the physiological responses, and their control, in freely diving birds and mammals that enable them to remain submerged and sometimes quite active for extended periods of time. Recent developments in technology have provided much detailed information on the behavior of these fascinating animals. Unfortunately, the advances in technology have been insufficient to enable physiologists to obtain anything like the same level of detail on the metabolic rate and physiological adjustments that occur during natural diving. This has led to much speculation and calculations b

APA, Harvard, Vancouver, ISO, and other styles

19

Vrbovská, Veronika, Ivo Sedláček, Michal Zeman, et al. "Characterization of Staphylococcus intermedius Group Isolates Associated with Animals from Antarctica and Emended Description of Staphylococcus delphini." Microorganisms 8, no. 2 (2020): 204. http://dx.doi.org/10.3390/microorganisms8020204.

Full text

Abstract:

Members of the genus Staphylococcus are widespread in nature and occupy a variety of niches, however, staphylococcal colonization of animals in the Antarctic environment has not been adequately studied. Here, we describe the first isolation and characterization of two Staphylococcus intermedius group (SIG) members, Staphylococcus delphini and Staphylococcus pseudintermedius, in Antarctic wildlife. Staphylococcus delphini were found exclusively in Adélie penguins. The report of S. pseudintermedius from Weddell seals confirmed its occurrence in all families of the suborder Caniformia. Partial RN

APA, Harvard, Vancouver, ISO, and other styles

20

van Polanen Petel, T. D., M. A. Giese, S. Wotherspoon, and M. A. Hindell. "The behavioural response of lactating Weddell seals (Leptonychotes weddellii) to over-snow vehicles: a case study." Canadian Journal of Zoology 85, no. 4 (2007): 488–96. http://dx.doi.org/10.1139/z07-029.

Full text

Abstract:

Over-snow vehicles are used extensively at Antarctic scientific research stations. Adult female Weddell seals ( Leptonychotes weddellii (Lesson, 1826)) also utilise the fast-ice and are therefore often exposed to vehicular activity, with the potential of affecting their behaviour. Guidelines for vehicular travel have been developed to minimise disturbance to Antarctic wildlife; however, these guidelines have not yet been scientifically tested. To examine the efficiency and sensitivity of existing guidelines used within the Australian Antarctic Territory (AAT), we conducted drive-by experiments

APA, Harvard, Vancouver, ISO, and other styles

21

Lydersen, Christian, Morten Skrede Ryg, Mike Osborne Hammill, and Peter James O'Brien. "Oxygen stores and aerobic dive limit of ringed seals (Phoca hispida)." Canadian Journal of Zoology 70, no. 3 (1992): 458–61. http://dx.doi.org/10.1139/z92-069.

Full text

Abstract:

In this paper we measured total lung capacity, myoglobin content of muscle tissue, and hemoglobin content of the blood of ringed seals (Phoca hispida). Based on this information and body composition analysis we estimated the total available oxygen stores of a diving average adult ringed seal (standard length 129 cm, body mass 73.7 kg) to be 4.5 L. The aerobic dive limit for a ringed seal of this size was estimated to be 8.9 min. Diving data from previous studies show that less than 4% of the dives of adult free-living ringed seals exceed this aerobic dive limit. Based on information from the l

APA, Harvard, Vancouver, ISO, and other styles

22

Moors, Hilary B., and John M. Terhune. "Calling depth and time and frequency attributes of harp (Pagophilus groenlandicus) and Weddell (Leptonychotes weddellii) seal underwater vocalizations." Canadian Journal of Zoology 83, no. 11 (2005): 1438–52. http://dx.doi.org/10.1139/z05-135.

Full text

Abstract:

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 occurr

APA, Harvard, Vancouver, ISO, and other styles

23

Ponganis, Paul J., Gerald L. Kooyman, Eugene A. Baranov, Philip H. Thorson, and Brent S. Stewart. "The aerobic submersion limit of Baikal seals, Phoca sibirica." Canadian Journal of Zoology 75, no. 8 (1997): 1323–27. http://dx.doi.org/10.1139/z97-756.

Full text

Abstract:

An aerobic dive limit (ADL), the diving duration beyond which postdive lactate concentration increases above the resting level, has been estimated theoretically for many species. Such calculations have been based on an oxygen store/diving metabolic rate (MR) equation. Until now, an ADL has been determined empirically from measurements of blood lactate concentration only in the Weddell seal, Leptonychotes weddellii. We measured post-submergence plasma lactate concentrations during spontaneous voluntary submersions of three captive adult Baikal seals (Phoca sibirica). Two-phase regression analys

APA, Harvard, Vancouver, ISO, and other styles

24

Kim, Yejin, In-Young Ahn, Ji Kang Park, and Won Young Lee. "Weddell seal observations on female and pup behavior and breeding status for four overwintering periods (2015 to 2018) at Barton Peninsula, King George Island, Antarctica." Czech Polar Reports 10, no. 1 (2020): 1–6. http://dx.doi.org/10.5817/cpr2020-1-1.

Full text

Abstract:

In animal ecology studies, it is a fundamental monitoring work to observe annual breeding cycle. In this study, we report the detailed observations on seven mother and pup pairs of Weddell seal (Leptonychotes weddellii) at Barton peninsula, King George Island, Antarctica. Two or three pairs had been observed along the coast on the fast ice in 2015, 2017, and 2018 and no breeding was recorded in 2016. Although it varied among individuals, pups were recorded to be born on 19−25 Sept., began swimming at day 18−19 after birth, and molted at day 21−25. Our observations may provide fundamental breed

APA, Harvard, Vancouver, ISO, and other styles

25

Schumacher, Udo, Peter Klein, Joachim Plötz, and Ulrich Welsch. "Histological, histochemical, and ultrastructural investigations on the gastrointestinal system of antarctic seals: Weddell seal (Leptonychotes weddellii) and crabeater seal (Lobodon carcinophagus)." Journal of Morphology 225, no. 2 (1995): 229–49. http://dx.doi.org/10.1002/jmor.1052250207.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Morejohn, G. Victor. "BACULUM OF THE WEDDELL SEAL WITH COMPARISONS TO OTHER PHOCID SEALS." Journal of Mammalogy 82, no. 3 (2001): 877. http://dx.doi.org/10.1644/1545-1542(2001)082<0877:botwsw>2.0.co;2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Testa, J. Ward. "A comment on the age at onset of breeding of male Weddell seals (Leptonychotes weddellii)." Canadian Journal of Zoology 75, no. 1 (1997): 156–57. http://dx.doi.org/10.1139/z97-021.

Full text

Abstract:

In an otherwise valuable contribution, Bartsh et al. (S.S. Bartsh, S.D. Johnston, and D.B. Siniff. 1992. Can. J. Zool. 70: 680 – 692) reached the conclusion that the youngest age at which male Weddell seals (Leptonychotes weddellii) become sexually active in their breeding colonies was 7 years, with first breeding likely, on average, in year 8. While plausible, this conclusion was based on only 5 seals of known age and 9 seals whose age was estimated from a length – age regression model. In addition to methodological problems with the regression model used by Bartsh et al., its application to

APA, Harvard, Vancouver, ISO, and other styles

28

Pahl, BC, JM Terhune, and HR Burton. "Proportional Weekly Use of Underwater Call Types by Weddell Seals, Leptonychotes Weddellii (Pinnipedia: Phocidae), During the Breeding Season at the Vestfold Hills." Australian Journal of Zoology 44, no. 1 (1996): 75. http://dx.doi.org/10.1071/zo9960075.

Full text

Abstract:

Underwater vocalisations by Weddell seals, Leptonychotes weddellii, were recorded during the 1992 breeding season, at the Vestfold Hills, Antarctica. Only 3 of the 12 major call types recorded at all sites had statistically significant variations in utilisation throughout the season. No consistent trends were evident. The underwater calls of Weddell seals increased;in number during the breeding season, hut the proportional weekly usage of each of the major call types did not change. The absence of vocalisation changes suggests that the breeding behaviours of Weddell seals are not synchronous a

APA, Harvard, Vancouver, ISO, and other styles

29

Testa, J. W. "Electromorph Variation in Weddell Seals (Leptonychotes weddelli)." Journal of Mammalogy 67, no. 3 (1986): 606–10. http://dx.doi.org/10.2307/1381302.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Testa, J. Ward. "Over-winter movements and diving behavior of female Weddell seals (Leptonychotes weddellii) in the southwestern Ross Sea, Antarctica." Canadian Journal of Zoology 72, no. 10 (1994): 1700–1710. http://dx.doi.org/10.1139/z94-229.

Full text

Abstract:

The movements and diving behavior of 18 adult female Weddell seals (Leptonychotes weddellii) were determined by satellite telemetry during the over-winter period in 1990 and 1991. Nine seals provided diving and movement data for 8 – 9 months. Seals that normally bred in the eastern part of McMurdo Sound spent most of the winter in the middle and northern parts of McMurdo Sound before the annual shore-fast ice had formed in those areas, or in the pack ice 0–50 km north of the sound and Ross Island. This is a greater use of pack ice, as opposed to shore-fast ice, in winter than was previously be

APA, Harvard, Vancouver, ISO, and other styles

31

Pahl, B. C., J. M. Terhune, and H. R. Burton. "Repertoire and Geographic Variation in Underwater Vocalisations of Weddell Seals (Leptonychotes weddellii, Pinnipedia : Phocidae) at the Vestfold Hills, Antarctica." Australian Journal of Zoology 45, no. 2 (1997): 171. http://dx.doi.org/10.1071/zo95044.

Full text

Abstract:

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 Hi

APA, Harvard, Vancouver, ISO, and other styles

32

Testa, J. Ward. "Long-term reproductive patterns and sighting bias in Weddell seals (Leptonychotes weddelli)." Canadian Journal of Zoology 65, no. 5 (1987): 1091–99. http://dx.doi.org/10.1139/z87-173.

Full text

Abstract:

The reproductive performance of tagged Weddell seals (Leptonychotes weddelli) was monitored at McMurdo Sound, Antarctica, from 1970 to 1984. An age-specific reproductive schedule revealed the major onset of pupping at age 6 years, and a mean age of first birth of 7.1 years. The average asymptotic pupping rate of 0.61 is reached by age 10. The cost of pupping in a given year is reflected in a 0.05 drop in the probability of pupping the following year. This cost is not evident in females over 7 years old, suggesting that postweaning condition affects newly mature females more than those that are

APA, Harvard, Vancouver, ISO, and other styles

33

Shaughnessy, P., and E. Erb. "Apparent twin pups of the Weddell seal Leptonychotes weddellii (Carnivora: Phocidae) near Mawson, Antarctica." Australian Mammalogy 25, no. 2 (2003): 197. http://dx.doi.org/10.1071/am03197.

Full text

Abstract:

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

APA, Harvard, Vancouver, ISO, and other styles

34

Castellini, M. A., G. L. Kooyman, and P. J. Ponganis. "Metabolic rates of freely diving Weddell seals: correlations with oxygen stores, swim velocity and diving duration." Journal of Experimental Biology 165, no. 1 (1992): 181–94. http://dx.doi.org/10.1242/jeb.165.1.181.

Full text

Abstract:

The metabolic rates of freely diving Weddell seals were measured using modern methods of on-line computer analysis coupled to oxygen consumption instrumentation. Oxygen consumption values were collected during sleep, resting periods while awake and during diving periods with the seals breathing at the surface of the water in an experimental sea-ice hole in Antarctica. Oxygen consumption during diving was not elevated over resting values but was statistically about 1.5 times greater than sleeping values. The metabolic rate of diving declined with increasing dive duration, but there was no signi

APA, Harvard, Vancouver, ISO, and other styles

35

Gelatt, Thomas S., Corey S. Davis, Donald B. Siniff, and Curtis Strobeck. "MOLECULAR EVIDENCE FOR TWINNING IN WEDDELL SEALS (LEPTONYCHOTES WEDDELLII)." Journal of Mammalogy 82, no. 2 (2001): 491–99. http://dx.doi.org/10.1644/1545-1542(2001)082<0491:meftiw>2.0.co;2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Weitzner, Emma L., Linnea E. Pearson, Lars Tomanek, and Heather E. M. Liwanag. "Early diving behavior in Weddell seal (Leptonychotes weddellii) pups." Journal of Mammalogy 102, no. 4 (2021): 1000–1008. http://dx.doi.org/10.1093/jmammal/gyab058.

Full text

Abstract:

Abstract During the dependency period in mammals with parental care, offspring must develop the behavioral skills that allow them to forage independently and thus survive into early adulthood. Deep-diving Weddell seals (Leptonychotes weddellii) are a model species for research on diving physiology, yet previous studies lack a thorough investigation into the diving behavior of dependent pups when they first begin to enter the water. To capture fine-scale dive behavior during the dependency period, we deployed time-depth recorders (TDRs) on Weddell seal pups (n = 18) from the age of 1 week throu

APA, Harvard, Vancouver, ISO, and other styles

37

KIM, S. L., K. CONLAN, D. P. MALONE, and C. V. LEWIS. "Possible food caching and defence in the Weddell seal: observations from McMurdo Sound, Antarctica." Antarctic Science 17, no. 1 (2005): 71–72. http://dx.doi.org/10.1017/s0954102005002452.

Full text

Abstract:

On the basis of observations of Weddell seals (Leptonychotes weddellii Lesson) made in the course of studying shallow-water benthic communities in McMurdo Sound, Antarctica, we suggest that caching and/or defence of uneaten food may be a strategy practiced by this animal. Such a phenomenon is uncommon but taxonomically widespread among vertebrates. Depending on circumstances, it is termed hoarding, caching, or storage and may be short- or long-term, include defence of the resource, or have other variable expressions, with the common threads being deferred consumption and deterrence of consumpt

APA, Harvard, Vancouver, ISO, and other styles

38

Doiron, Elyse E., Philippe A. Rouget, and John M. Terhune. "Proportional underwater call type usage by Weddell seals (Leptonychotes weddellii) in breeding and nonbreeding situations." Canadian Journal of Zoology 90, no. 2 (2012): 237–47. http://dx.doi.org/10.1139/z11-131.

Full text

Abstract:

Proportional underwater call type usage by Weddell seals ( Leptonychotes weddellii (Lesson, 1826)) near Mawson, Antarctica, investigated the hypothesis that certain call types function specifically in breeding behaviour. Recordings were collected at various sites in 2000 and 2002 from June to December. Twenty-four hour recordings were collected in 2002 at two sites. One hundred consecutive calls from each of 248 recordings were classified into one of ten common call types. Time to 100 calls provided the calling rate. The study period was divided into four periods representing initial sea-ice f

APA, Harvard, Vancouver, ISO, and other styles

39

Burns, Jennifer M. "The development of diving behavior in juvenile Weddell seals: pushing physiological limits in order to survive." Canadian Journal of Zoology 77, no. 5 (1999): 737–47. http://dx.doi.org/10.1139/z99-022.

Full text

Abstract:

In juvenile phocids, the successful transition from nursing to independent foraging is contingent upon the development of adequate diving skills within the limited time between weaning and the depletion of body reserves. Yet, because juvenile seals are unable to remain submerged for as long as adults, owing to their smaller size, higher metabolic rates, and lowered oxygen stores, their behavioral options are likely constrained. To determine how such limitations might influence foraging strategies, we studied the development of diving behavior and physiology in Weddell seal (Leptonychotes wedde

APA, Harvard, Vancouver, ISO, and other styles

40

Stephenson, Richard. "A Theoretical Analysis of Diving Performance in the Weddell Seal (Leptonychotes weddelli)." Physiological and Biochemical Zoology 78, no. 5 (2005): 782–800. http://dx.doi.org/10.1086/432142.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Noren, Shawn R., Linnea E. Pearson, Jay Davis, Stephen J. Trumble, and Shane B. Kanatous. "Different Thermoregulatory Strategies in Nearly Weaned Pup, Yearling, and Adult Weddell Seals (Leptonychotes weddelli)." Physiological and Biochemical Zoology 81, no. 6 (2008): 868–79. http://dx.doi.org/10.1086/588489.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Todd, Frank S. "Weddell Seal Preys on Chinstrap Penguin." Condor 90, no. 1 (1988): 249–50. http://dx.doi.org/10.2307/1368459.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Testa, J. W., Donald B. Siniff, John P. Croxall, and Harry R. Burton. "A Comparison of Reproductive Parameters Among Three Populations of Weddell Seals (Leptonychotes weddellii)." Journal of Animal Ecology 59, no. 3 (1990): 1165. http://dx.doi.org/10.2307/5038.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Rogers, T. L., K. T. Collins, R. G. Harcourt, K. E. Wheatley, P. D. McGreevy, and J. M. Terhune. "Individual variation of in-air female 'pup contact' calls in Weddell seals, Leptonychotes weddellii." Behaviour 142, no. 2 (2005): 167–89. http://dx.doi.org/10.1163/1568539053627668.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Sipilä, Tero, and Heikki Hyvärinen. "Status and biology of Saimaa (Phoca hispida saimensis) and Ladoga (Phoca hispida ladogensis) ringed seals." NAMMCO Scientific Publications 1 (June 5, 1998): 83. http://dx.doi.org/10.7557/3.2982.

Full text

Abstract:

Saimaa (Phoca hispida saimensis) and Ladoga (P. h. ladogensis) seals are subspecies of ringed seals that live in freshwater lakes. The founding populations for these two subspecies became separated from Arctic ringed seals (P. h. hispida) during the last ice age. The Saimaa seal population currently numbers approximately 200 seals with 36 - 40 pups born annually. The Ladoga seal population contains at least 5,000 seals. The weight of adult animals in Lake Saimaa is 45-100 kg (mean 62 kg) and in Lake Ladoga adults weigh 32-56 kg (mean 47 kg). The lanugo of Saimaa seals is grey. Normally pups in

APA, Harvard, Vancouver, ISO, and other styles

46

Macdonald, Alastair A., Christopher Dixon, and Ian L. Boyd. "Comparative anatomy of the cardiac foramen ovale in the Pinnipedia." Canadian Journal of Zoology 73, no. 5 (1995): 850–57. http://dx.doi.org/10.1139/z95-100.

Full text

Abstract:

The structure of the cardiac foramen ovale from eight genera of pinnipeds was studied using the scanning electron microscope. Specimens were obtained from fetuses or neonates of the Californian sea lion (Zalophus californianus), Antarctic fur seal (Arctocephalus gazella), walrus (Obenus rosmarus), grey seal (Halichoerus gryphus), ringed seal (Phoca hispida), bearded seal (Erignathus barbatus), Weddell seal (Leptonychotes weddelli), and crabeater seal (Lobodon carcinophagus). In each species, the structure that permits oxygenated blood from the placenta flowing in the caudal vena cava to pass d

APA, Harvard, Vancouver, ISO, and other styles

47

Terhune, John M., and Andrea Dell'Apa. "Stereotyped Calling Patterns of a Male Weddell Seal (Leptonychotes weddellii)." Aquatic Mammals 32, no. 2 (2006): 175–81. http://dx.doi.org/10.1578/am.32.2.2006.175.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Burns, Jennifer M., Michael A. Castellini, and Jason F. Schreer. "Physiological effects on dive patterns and foraging strategies in yearling Weddell seals (Leptonychotes weddellii)." Canadian Journal of Zoology 75, no. 11 (1997): 1796–810. http://dx.doi.org/10.1139/z97-809.

Full text

Abstract:

Fifteen yearling Weddell seals (Leptonychotes weddellii) were captured, measured, weighed, bled, equipped with time–depth recorders, and released to determine if diving behavior was related to physical condition. Upon recovery of the time–depth recorders, dives were classified into four types based on shape, using cluster analysis. Based on maximum depth, two groups were further subdivided, for a total of seven types. The mean and maximal dive depth, duration, and frequency were determined for each yearling for all dive types combined and for each type separately. Stepwise regression and ANOVA

APA, Harvard, Vancouver, ISO, and other styles

49

Sedláček, Ivo, Linda Grillová, Eva Kroupová, Jitka Černohlávková, and David Šmajs. "Isolation of human pathogen Escherichia albertii from faeces of seals (Leptonychotes weddelli) in James Ross Island, Antarctica." Czech Polar Reports 3, no. 2 (2013): 173–83. http://dx.doi.org/10.5817/cpr2013-2-18.

Full text

Abstract:

A set of nine gram-negative fermenting rods biochemically identified as Escherichia coli was isolated from faeces of seals. These bacteria were characterized by phenotypic classification, 16S rDNA sequence analyses, automated ribotyping, study of whole-cell protein profiles by SDS-PAGE and finally by bacteriocin production. The results of our polyphasic taxonomic study supported the recognition of P4652, P4653 and P4740 isolates as true members of Escherichia albertii species – probably a major enteric human pathogen. To our best knowledge, this is the first evidence showing that E. albertii p

APA, Harvard, Vancouver, ISO, and other styles

50

Osinga, Nynke, and Pieter ‘t Hart. "Harbour seals (Phoca vitulina) and rehabilitation." NAMMCO Scientific Publications 8 (September 1, 2010): 355. http://dx.doi.org/10.7557/3.2699.

Full text

Abstract:

Throughout the past few decades, rehabilitation of seals has become an activity that is anchored in the present day society of many countries. Seals are primarily rehabilitated to help individual animals in distress. At the same time, the release of seals which would have otherwise died can be considered as a contribution to the population. Most rehabilitated seals are animals under one year of age. They are mainly orphans, weaned seals with complications and seals with a parasiticbronchopneumonia. For the optimal handling of seals and their diseases, centralised operations with quality standa

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!