Ecology of the ringed seal, Phoca hispida, in its fast ice breeding habitat

1981 ◽  
Vol 59 (6) ◽  
pp. 966-981 ◽  
Author(s):  
Thomas G. Smith ◽  
Michael O. Hammill
Keyword(s):  
Behavioral Ecology ◽  
Population Regulation ◽  
Weddell Seal ◽  
Breeding Habitat ◽  
Baffin Island ◽  
Phoca Hispida ◽  
Fast Ice ◽  
Site Tenacity ◽  
Males And Females ◽  
The Antarctic

Studies of the behavioral ecology of seals hauled out on the sea ice at Popham Bay (64°17′ N, 65°30′ W) southeastern Baffin Island were conducted from 8 May to 6 June 1978 and 1 May to 20 June 1979. Similar densities and seasonal changes in numbers of hauled out seals were seen in both years. Seal numbers were positively correlated with date and negatively correlated with wind speed. While lying on the ice seals were vigilant and aggressive towards other seals, and females suckled their pups. Individuals were recognized by their different pelage marks. Both males and females showed site tenacity. One male, seen in 1978, was resighted in the study area in 1979. Our observations indicate that ringed seals are territorial and similar to the polygynous Weddell seal of the antarctic in their social organization. Population regulation appears to be affected by availability of suitable fast ice in which to maintain feeding and breeding habitat, with some adjustment of annual recruitment possibly in response to depleted food resources.

Characteristics of ringed seal, Phoca hispida, subnivean structures and breeding habitat and their effects on predation

1996 ◽  
Vol 74 (5) ◽  
pp. 858-874 ◽  
Author(s):  
C. M. Furgal ◽  
K. M. Kovacs ◽  
S. Innes
Keyword(s):  
Snow Depth ◽  
Function Analysis ◽  
Ringed Seal ◽  
Breeding Habitat ◽  
Phoca Hispida ◽  
Ringed Seals ◽  
Arctic Foxes ◽  
Ridge Height ◽  
Length Width ◽  
Fast Ice

Characteristics of ringed seal (Phoca hispida) subnivean structures and breeding habitat were quantified and their potential influence on predation success by polar bears (Ursus maritimus), arctic foxes (Alopex lagopus), and humans on ringed seals was investigated in Admiralty Inlet and Strathcona Sound, Northwest Territories. A total of 237 ringed seal structures were located between April and June 1991–1993 using trained dogs. Ringed seal lairs and breathing holes were concentrated in areas of deep snow, and were associated with large, thick ice ridges. Only a small percentage of the available fast-ice habitat had sufficient snow depth for lair construction each year. A discriminant function analysis used to classify structures located in 1992, using a combination of structural and habitat measurements, correctly classified 70% of structures located in 1991 and 1993 into functional groups. The length, width, internal height, and level of "tiggak," the odour of rutting male ringed seals, associated with structures were the most important descriptors separating structure types. Seventy-three percent of structures located in the study were undisturbed by predators. The mean length and width of structures entered by predators were significantly greater than those of undisturbed structures. Polar bear success decreased as snow depth and the thickness of the roof covering the structures increased. The conditions necessary for successful arctic fox predation are unclear. Inuit hunters attacked structures close to ice ridges, and ridge height and snow depth influenced their success. All predators attacked lairs having the odour of rutting male ringed seals less often than structures with no male odour.

Spatiotemporal use of lairs by ringed seals (Phoca hispida)

1990 ◽  
Vol 68 (12) ◽  
pp. 2503-2512 ◽  
Author(s):  
Brendan P. Kelly ◽  
Lori T. Quakenbush
Keyword(s):  
Early Spring ◽  
Late Spring ◽  
Phoca Hispida ◽  
Ringed Seals ◽  
Fast Ice ◽  
Males And Females

Thirteen ringed seals monitored by radiotelemetry in the shore-fast ice of the Beaufort and Chukchi seas were faithful to subnivean haulout sites from March to June. Each seal frequented as many as four lairs; the distances between lairs used by individual seals were as great as 3438 m. Mean distances between lairs used by individual males and females were 1997 and 634 m, respectively. Seals were not commonly seen resting on the ice outside of lairs until late May or June, but two radio-tagged male seals began basking on 15 April and 7 May, respectively. The proportion of time spent out of the water was 12.1% in March, 18.6% in April, 21.9% in May, and 42.9% in early June. From late March to June, males were out of the water during 13.1% of the monitored periods, and females were out of the water during 24.0% of those periods. Mean hours of haulout bouts were between 18:00 and 02:30 in early spring (except for a lactating female who hauled out most frequently at 11:00) and between 10:00 and 16:30 in late spring.

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz
Keyword(s):  
Sex Ratio ◽  
Ringed Seal ◽  
Adult Males ◽  
Population Parameters ◽  
Phoca Hispida ◽  
Age Class ◽  
Ringed Seals ◽  
Males And Females ◽  
The Mean ◽  
Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

Hunting Behavior of a Marine Mammal Beneath the Antarctic Fast Ice

Science ◽  
1999 ◽  
Vol 283 (5404) ◽  
pp. 993-996 ◽  
Author(s):  
R. W. Davis ◽  
L. A. Fuiman ◽  
T. M. Williams ◽  
S. O. Collier ◽  
W. P. Hagey ◽  
...  
Keyword(s):  
Marine Mammal ◽  
Hunting Behavior ◽  
Fast Ice ◽  
The Antarctic

The breeding habitat of the ringed seal (Phoca hispida). The birth lair and associated structures

1975 ◽  
Vol 53 (9) ◽  
pp. 1297-1305 ◽  
Author(s):  
Thomas G. Smith ◽  
Ian Stirling
Keyword(s):  
Ursus Maritimus ◽  
Ringed Seal ◽  
Breeding Habitat ◽  
Polar Bears ◽  
Alopex Lagopus ◽  
Phoca Hispida ◽  
Arctic Foxes ◽  
Different Types ◽  
Amundsen Gulf

The subnivean lairs of the ringed seal (Phoca hispida) were studied in the Amundsen Gulf and Prince Albert Sound areas from 1971 through 1974. The structure of several different types of lairs are described. The existence of a birth-lair complex consisting of several closely adjacent lairs appears likely. The spacial distribution of lairs and lair types found on refrozen leads and in pressure ridges is described. Lairs were more abundant in inshore ice than in offshore ice. The function of subnivean lairs appears to be to provide thermal shelter, especially for neonate seals, and protection from predation by arctic foxes (Alopex lagopus) and polar bears (Ursus maritimus).

scholarly journals Cetacean records along a coastal-offshore gradient in the Vitória-Trindade Chain, western South Atlantic Ocean

2014 ◽  
Vol 74 (1) ◽  
pp. 137-144 ◽  
Author(s):  
LL Wedekin ◽  
MR Rossi-Santos ◽  
C Baracho ◽  
AL Cypriano-Souza ◽  
PC Simões-Lopes
Keyword(s):  
Humpback Whale ◽  
South Atlantic ◽  
Breeding Habitat ◽  
Humpback Whales ◽  
Balaenoptera Physalus ◽  
Fin Whale ◽  
Antarctic Minke Whale ◽  
Trindade Island ◽  
The Antarctic ◽  
Species Being

Oceanic waters are difficult to assess, and there are many gaps in knowledge regarding cetacean occurrence. To fill some of these gaps, this article provides important cetacean records obtained in the winter of 2010 during a dedicated expedition to collect visual and acoustic information in the Vitória-Trindade seamounts. We observed 19 groups of cetaceans along a 1300-km search trajectory, with six species being identified: the humpback whale (Megaptera novaeangliae, N = 9 groups), the fin whale (Balaenoptera physalus, N = 1), the Antarctic minke whale (Balaenoptera bonaerensis, N = 1), the rough-toothed dolphin (Steno bredanensis, N = 1), the bottlenose dolphin (Tursiops truncatus, N = 2), and the killer whale (Orcinus orca, N = 1). Most humpback whale groups (N = 7; 78%) were observed in the Vitória-Trindade seamounts, especially the mounts close to the Abrolhos Bank. Only one lone humpback whale was observed near Trindade Island after a search effort encompassing more than 520 km. From a total of 28 acoustic stations, humpback whale songs were only detected near the seamounts close to the Abrolhos Bank, where most groups of this species were visually detected (including a competitive group and groups with calves). The presence of humpback whales at the Trindade Island and surroundings is most likely occasional, with few sightings and low density. Finally, we observed a significant number of humpback whales along the seamounts close to the Abrolhos Bank, which may function as a breeding habitat for this species. We also added important records regarding the occurrence of cetaceans in these mounts and in the Western South Atlantic, including the endangered fin whale.

Maternal behaviour and energy investment by grey seals (Halichoerus grypus) breeding on land-fast ice

1996 ◽  
Vol 74 (8) ◽  
pp. 1531-1541 ◽  
Author(s):  
Martha A. Haller ◽  
Kit M. Kovacs ◽  
Mike O. Hammill
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Breeding Season ◽  
Breeding Habitat ◽  
Halichoerus Grypus ◽  
Maternal Behaviour ◽  
Similar Amount ◽  
Lactation Period ◽  
Energy Investment ◽  
Fast Ice

The grey seal (Halichoerus grypus) is a sexually dimorphic polygynous phocid that breeds in a synchronous fashion, within populations, on both sides of the North Atlantic Ocean. This study was designed to examine factors that may influence maternal behaviour and energy investment of females breeding on land-fast ice. The study was conducted on the ice around Amet Island, Nova Scotia, during the breeding seasons of 1992, 1993, and 1994. Scan sampling and ad libitum observation techniques were used to record behaviour. Mass transfer from mothers to pups was determined using serial mass records for pairs. Rate of pup mass gain was 2.5 ± 0.6 kg/day and pup mass at weaning 50.0 ± 7.3 kg. The duration of lactation was 15.2 ± 1.6 days. Maternal mass at parturition was 210.6 ± 23.8 kg and female mass loss during the lactation period was 75.0 ± 16.0 kg. This mass loss represented 35.7 ± 6.1% of their parturition mass. Efficiency of mass transfer was 0.52 ± 0.12. Breeding habitat influenced maternal behaviour. Compared with land-breeding grey seals, ice-breeding females had an intensified nursing period, during which females transferred a similar amount of energy to their pups over a shorter time frame. Additionally, females on land-fast ice gave birth more synchronously than is the case in land-breeding colonies. Date of parturition within the breeding season had some influence on female behaviour; females giving birth late in the season were more active than females breeding earlier. The behaviour of males may play a role in determining the optimum time for birthing. Adult males spent more time engaged in agonistic behaviours late in the breeding season and the resultant disruption of adjacent females may serve as a selective force maintaining birthing synchrony. These influences also apply in land-breeding situations and are not likely to contribute to the contraction of the nursing period and the more synchronous breeding observed among females on ice. The more condensed lactation and birthing periods are likely a response to the higher risk of premature separation on the ice.

scholarly journals Hot-Water Drilling in the Antarctic Peninsula (Abstract)

1988 ◽  
Vol 11 ◽  
pp. 215
Author(s):  
S. Cooper
Keyword(s):  
Antarctic Peninsula ◽  
Temperature Sensors ◽  
Back Pressure ◽  
Hot Water ◽  
Ice Shelves ◽  
Pilot Hole ◽  
Fast Ice ◽  
Drilling System ◽  
The Antarctic ◽  
Practical Field

The British Antarctic Survey has developed a hot-water drilling system used chiefly for installing temperature sensors through ice shelves and for retrieving oceanographic equipment tethered through thick fast ice. The specification, design and operation of the drill for these two activities will be discussed and practical field problems will be highlighted. A novel aspect of the design is the use of reaming nozzles to enlarge a pilot hole. These nozzles eject water upwards along the surface of the nozzle cone, and drill most efficiently when they hang free and unsupported by the sides of the pilot hole. The nozzles incorporate a nozzle-mounted valve, activated when the nozzle cone contacts the ice, thus increasing the back pressure of the water flow. The pressure increase is monitored at the surface and the winch speed is reduced accordingly in order to ensure an efficient drilling operation.

Analysis of ZP1 gene reveals differences in zona pellucida composition in carnivores

2018 ◽  
Vol 30 (2) ◽  
pp. 272 ◽  
Author(s):  
C. Moros-Nicolás ◽  
A. Leza ◽  
P. Chevret ◽  
A. Guillén-Martínez ◽  
L. González-Brusi ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
In Silico ◽  
Polar Bear ◽  
Acrosome Reaction ◽  
Stop Codon ◽  
In Silico Analysis ◽  
Weddell Seal ◽  
Fur Seal ◽  
The Antarctic ◽  
Silico Analysis

The zona pellucida (ZP) is an extracellular envelope that surrounds mammalian oocytes. This coat participates in the interaction between gametes, induction of the acrosome reaction, block of polyspermy and protection of the oviductal embryo. Previous studies suggested that carnivore ZP was formed by three glycoproteins (ZP2, ZP3 and ZP4), with ZP1 being a pseudogene. However, a recent study in the cat found that all four proteins were expressed. In the present study, in silico and molecular analyses were performed in several carnivores to clarify the ZP composition in this order of mammals. The in silico analysis demonstrated the presence of the ZP1 gene in five carnivores: cheetah, panda, polar bear, tiger and walrus, whereas in the Antarctic fur seal and the Weddell seal there was evidence of pseudogenisation. Molecular analysis showed the presence of four ZP transcripts in ferret ovaries (ZP1, ZP2, ZP3 and ZP4) and three in fox ovaries (ZP2, ZP3 and ZP4). Analysis of the fox ZP1 gene showed the presence of a stop codon. The results strongly suggest that all four ZP genes are expressed in most carnivores, whereas ZP1 pseudogenisation seems to have independently affected three families (Canidae, Otariidae and Phocidae) of the carnivore tree.

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