Diving in ringed seal (Phoca hispida) pups during the nursing period

1993 ◽  
Vol 71 (5) ◽  
pp. 991-996 ◽  
Author(s):  
Christian Lydersen ◽  
Mike O. Hammill
Keyword(s):  
Short Duration ◽  
Average Duration ◽  
Dive Duration ◽  
Ringed Seal ◽  
Young Age ◽  
White Coat ◽  
Polar Bears ◽  
Phoca Hispida ◽  
Study Activity ◽  
The Mean

In this study, activity and diving performance of nursing ringed seal (Phoca hispida) pups were quantified using time–depth recorders. A total of 1040 h of activity, including 7506 diving cycles, was collected from three female pups. The pups spent 50.3% of their time in the water and 49.7% hauled out on the ice. When the pups were in the water, 20.5% of the time was spent actively diving, while 79.5% of the recorded wet time was spent at the surface. Most of the dives were shallow and of short duration. Mean dive duration was 59.1 ± 63.5 s (SD). Maximum dive durations for the three pups were 5.8, 7.5, and 12 min. Maximum recorded depths were 12, 35, and 89 m. These depths represented the bottom in the area where each pup was situated. The average duration of haul-out sessions where nursing could take place was 6.3 ± 1.6 h, and the time between these sessions was 8.2 ± 3.2 h. The mean number of breathing holes found per pup was 8.7 ± 3.5. The large proportion of time spent in the water, the development of diving skills at an extremely young age, the use of multiple breathing holes, and the prolonged white-coat stage are all interpreted to be evolutionary responses to strong predation pressure, mainly from polar bears.

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.

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).

Midsummer observations on the behavior of wild polar bears (Ursus maritimus)

1974 ◽  
Vol 52 (9) ◽  
pp. 1191-1198 ◽  
Author(s):  
Ian Stirling
Keyword(s):  
Diurnal Rhythm ◽  
Intraspecific Competition ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Phoca Hispida ◽  
Devon Island ◽  
Adult Females ◽  
Ringed Seals ◽  
Single Animal ◽  
The Mean

Wild polar bears (Ursus maritimus) were observed from Caswall Tower, Devon Island (74°43′ N; 91°10′ W), from 24 July to 8 August 1973. A total of 602.7 bear hours of observations was recorded. Two types of hunting were observed, stalking and still-hunting. Of 288 hunts observed, 65 (22.6%) were stalks and 233 (77.4%) were still-hunts. All cubs observed hunted, but they exhibited great variety in patience and apparent skill. Scavenging and intraspecific competition for possession of kills were observed. When threatened, adult females with cubs were not subordinate to tears of any other age or sex classes. A diurnal rhythm was recorded in which bears slept most during the latter third of the 24-h cycle and least in the first third. The average of 17 sleeps longer than 60 min was 465 ± 301.3 min.Basking ringed seals (Phoca hispida) alternated between lying flat and raising their heads to look about for predators. The mean duration of the lying and looking phases was 26.3 and 7.0 s respectively (n = 591 and 580). The variation between individual seals was greater than within individuals. If a group of seals hauled out together, all individuals maintained watchful behavior; no single animal acted as a "sentry" for the others.

Ringed seal diving behavior in the breeding season

1996 ◽  
Vol 74 (8) ◽  
pp. 1547-1555 ◽  
Author(s):  
Brendan P. Kelly ◽  
Douglas Wartzok
Keyword(s):  
Breeding Season ◽  
Light Level ◽  
Dive Depth ◽  
Dive Duration ◽  
Ringed Seal ◽  
Diving Behavior ◽  
Adult Males ◽  
Phoca Hispida ◽  
Oxygen Stores ◽  
Lactating Females

The behavior of 14 ringed seals (Phoca hispida) diving under shore-fast sea ice was monitored acoustically during the spring breeding season. Frequent dives with extended periods at depth by subadult and adult seals, including lactating females, were interpreted to be foraging dives. Median dive durations were less than 10.0 min for all seals, and the maximal observed duration was 26.4 min. The maximal observed dive depth, 222 m, was limited by water depth in the study area. Modal dive depths were between 10 and 45 m for breeding-age males and between 100 and 145 m for subadult males and postparturient females. Median dive durations were 4.0 min for adult males and 7.5 min for adult females. Body mass was a better predictor of maximal dive duration (r2 = 0.94) than was age, but maximal durations were shorter than were predicted using measures of oxygen stores and presumed metabolic rates. There was no consistent relationship between light level and the frequency or depth of dives.

Monitoring ringed seal (Phoca hispida) activity by means of acoustic telemetry

1991 ◽  
Vol 69 (5) ◽  
pp. 1178-1182 ◽  
Author(s):  
Christian Lydersen
Keyword(s):  
Acoustic Telemetry ◽  
Dive Depth ◽  
Dive Duration ◽  
Ringed Seal ◽  
Diurnal Pattern ◽  
Phoca Hispida ◽  
Late Afternoon ◽  
Continuous Activity

This study was conducted in Kongsfjorden, Svalbard (78°55′N, 12°30′E), from May 6 to 13, 1989. An adult ringed seal (Phoca hispida) female was live captured and equipped with an acoustic depth–time transmitter to obtain information on diving and haul-out activities. A total of 153 h continuous activity, including 1321 diving cycles, was recorded. Of the total time, 38.2% was spent underwater, 16.6% breathing at the surface, and 45.2% hauling out on the ice. Excluding haul-out periods, the seal was submerged for 69.7% and at the surface for 30.3% of the total time spent in the water. Mean dive duration was 2.7 ± 2.7 (SD) min, and mean dive depth was 10.6 ± 9.0 m. Maximum recorded dive duration was 17 min, and maximum recorded dive depth was 40 m. Recorded activities showed a diurnal pattern, with most of the diving activities in the late afternoon and at night and most of the haul-out activity in the morning and during the day.

Diving activity in nursing bearded seal (Erignathus barbatus) pups

1994 ◽  
Vol 72 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Christian Lydersen ◽  
Mike O. Hammill ◽  
Kit M. Kovacs
Keyword(s):  
Short Duration ◽  
Mass Gain ◽  
Dive Depth ◽  
Dive Duration ◽  
Diurnal Pattern ◽  
Bearded Seal ◽  
Erignathus Barbatus ◽  
The Mean

In this study we used time-depth recorders to quantify the diving activity of four nursing bearded seal (Erignathus barbatus) pups over a 10-day period. The pups were 4–7 days old at the start of the experiments. Their daily mass gain was 3.3 ± 0.4 kg (mean ± SD). A total of 530 h, which included 6248 dives, was recorded from the four pups. The pups spent an average of 53% of the recorded time in the water and 47% of the time hauled out. When the pups were in the water they were submerged 42% of the time, while 58% of the time was spent at the surface. Most dives were shallow and of short duration. Dive depth and duration were 10 ± 10 m and 62 ± 46 s and the maximum recorded values were 84 m and 5.5 min, respectively. The pups spent more time in the water and increased the number of long dives and the mean dive duration with age. The duration of haul-out intervals where nursing could take place was 1.93 ± 2.01 h, with a recorded maximum of 8.25 h. The time between these haul-out intervals was 2.18 ± 2.44 h, with a maximum of 9.73 h. A diurnal pattern in haul-out activity was documented; pups spent significantly more time hauled out from 07:00 to 10:00 and from 21:00 to 24:00 than during the rest of the day.

The ringed seal (Phoca hispida) spring diet in northwestern Spitsbergen, Svalbard

1986 ◽  
Vol 4 (1) ◽  
pp. 53-56 ◽  
Author(s):  
Ian Gjertz ◽  
Christian Lydersen
Keyword(s):  
Ringed Seal ◽  
Phoca Hispida

scholarly journals Mono-ortho and non-ortho substituted PCBs in Arctic ringed seal (Phoca hispida) from the Svalbard area: Analysis and determination of their toxic threat

Chemosphere ◽  
1993 ◽  
Vol 27 (1-3) ◽  
pp. 429-437 ◽  
Author(s):  
F.F. Daelemans ◽  
F. Mehlum ◽  
C. Lydersen ◽  
P.J.C. Schepens
Keyword(s):  
Ringed Seal ◽  
Phoca Hispida

Distribution and abundance of ringed (Phoca hispida) and bearded seals (Erignathus barbatus) in western Hudson Bay

1997 ◽  
Vol 54 (4) ◽  
pp. 914-921 ◽  
Author(s):  
N J Lunn ◽  
I Stirling ◽  
S N Nowicki
Keyword(s):  
Polar Bear ◽  
Hudson Bay ◽  
Phoca Hispida ◽  
Current Estimate ◽  
Ringed Seals ◽  
Erignathus Barbatus ◽  
The Mean ◽  
Western Hudson Bay ◽  
The Relationship ◽  
Bearded Seals

We flew a medium-altitude, systematic, strip-transect survey for ringed (Phoca hispida) and bearded seals (Erignathus barbatus) over western Hudson Bay in early June 1994 and 1995. The mean density (per square kilometre) of ringed seals hauled out on the ice was four times higher in 1995 (1.690) than in 1994 (0.380). The 1994 survey appeared to underestimate seal abundance because it was flown too late. Ringed seals preferred high ice cover habitat (6 + /8 ice) and, within this habitat, favoured cracking ice and large floes. We found no consistent effect of either wind or cloud cover on habitat preference. We estimated a total of 1980 bearded seals and 140<|>880 ringed seals hauled out on the sea ice in June 1995. A recent review of the relationship between ringed seal and polar bear (Ursus maritimus) populations suggests that a visible population of this size should support a population of up to 1300 polar bears, which is in general agreement with the current estimate of 1250-1300 bears in western Hudson Bay.

The Ontogeny of Ultrasonic Vocalization in Microtus Montanus

Behaviour ◽  
1977 ◽  
Vol 60 (1-2) ◽  
pp. 115-121 ◽  
Author(s):  
V.J. De Ghett
Keyword(s):  
Short Duration ◽  
Maternal Care ◽  
Ultrasonic Vocalization ◽  
Ultrasonic Vocalizations ◽  
Developmental Changes ◽  
Maternal Behaviour ◽  
Postnatal Ontogeny ◽  
Microtus Montanus ◽  
Early Peak ◽  
The Mean

AbstractDevelopmental changes in parameters of ultrasound production were investigated in M. montanus young. The rate of ultrasonic vocalization reached a peak on Day 2 of postnatal ontogeny and declined to zero on Day 15. A similar developmental pattern has been found in several other rodent species. However, the comparatively early peak rate is indicative of a degree of ontogenic precociousness. Other developmental changes, both behavioural and morphological, tend to confirm that M. montanus young are relatively precocious. The duration of ultrasonic vocalizations did not show a significant change across early development. The mean duration for each vocalization sampled was 22.92 msec. The distribution of these vocalizations showed that a considerable number of vocalizations were of very short duration (<30 msec). The developmental changes in the percentage of young emitting ultrasounds began to decline following Day 8 and reached zero percent on Day 15. This decline in the percentage of young vocalizing corresponded to changes in maternal behaviour. Both the rate of ultrasonic vocalization and the percentage of young vocalizing were significantly correlated with the age of the young. Being correlated with age, these parameters of ultrasound production have the possibility of having great communicative value for the purposes of maternal care.

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