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.

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.

scholarly journals Status and biology of ringed seals (Phoca hispida) in Svalbard

1998 ◽  
Vol 1 ◽  
pp. 46 ◽  
Author(s):  
Christian Lydersen
Keyword(s):  
Body Mass ◽  
Dive Duration ◽  
Early Spring ◽  
Ringed Seal ◽  
The Arctic ◽  
Polar Cod ◽  
Net Energy ◽  
Adult Males ◽  
Ringed Seals ◽  
Males And Females

The ringed seal is the most abundant mammal in the Svalbard area. Annual pup production in this area is estimated to be 20,000. No systematic harvest records exist, but some few hundred seals are taken annually, mainly for dog food. The ringed seals in Svalbard are protected from hunting in the period 15 March - 15 April. Peak pupping season is the first week of April. New-born ringed seals weigh an average of 4.6 kg. They are nursed for about 39 days, and weaned at an average body mass of around 22 kg. During the period of maternal care pups consume a total of about 54 litres of milk, that is composed of approximately 38% fat and 10% protein. Asymptotic standard lengths and body masses for adult ringed seal males and females are 131.5 and 127.8 cm, and 52.6 and 59.9 kg,respectively. The maximum values recorded for lengths of males and females in Svalbard are 157 cm and 107 kg, respectively. There is marked seasonal variation in body mass in both sexes with the highest mass records being recorded in early spring before pupping occurs, and with minimum values in the summer after the breeding and moulting seasons. The observed variation in mass is mainly due to changing blubber thickness of the seals. Ringed seal males attain sexual maturity at the age of 5 - 7 years, while females reach maturity when they are 3-5 years of age. The oldest seal collected in Svalbard was aged 45. Ringed seals in the Svalbard area feed on a variety of prey organisms, the most important of which are polar cod (Boreogadus saida) and the crustaceans Parathemisto libellula, Thysanoessa inermis and Pandalus borealis. Ringed seal pups start diving during the nursing period while they are still white-coats, and spend about 50% of the time in thewater prior to weaning. They are capable of diving for up to 12min and dive to the bottom of the study areas (max. 89 m). Nursing females spend more than 80% of their time in the water. Maximum recorded dive duration for mothers was 21.2 min. In order to produce a weaned pup, the net energy expenditure for a ringed seal mother is 1,073 MJ. This energy value corresponds to the consumption of 185 kg of polar cod or 282 kg of P. libellula. The annual gross energy consumption for adult males and females is calculated to be 5,600 MJ and 7,300 MJ, respectively. The main predators of ringed seals in Svalbard are polar bears (Ursus maritimus) and Arctic foxes (Alopex lagopus). In addition, both glaucous gulls (Larus hyperboreus) and walruses (Odobenus rosmarus) are documented as predators of ringed seals in this area. Heavy predation pressure is probably the main factor explaining why pups of this species start diving at such a young age, why they have access to so many breathing holes (8.7 on average) and why they keep their white coat long after its thermoregulatory properties have vanished. Pollution levels in ringed seals from Svalbard are, generally speaking, similar to levels in other areas of the Arctic.

Reproductive effort of male hooded seals (Cystophora cristata): estimates from mass loss

1996 ◽  
Vol 74 (8) ◽  
pp. 1521-1530 ◽  
Author(s):  
Kit M. Kovacs ◽  
Christian Lydersen ◽  
Mike Hammill ◽  
David M. Lavigne
Keyword(s):  
Body Composition ◽  
Mass Loss ◽  
Body Mass ◽  
Breeding Season ◽  
Tritiated Water ◽  
Dive Depth ◽  
Dive Duration ◽  
Day Range ◽  
Ice Surface ◽  
Cystophora Cristata

This study investigated mass loss, body composition, and behaviour patterns of male hooded seals during the reproductive season. During the 6 years of study (between 1989 and 1995), 139 records of male mass were obtained that involved 115 individuals. Body masses of males ranged from 147 to 434 kg. Mean mass at first capture was 312.5 ± 53.0 kg (N = 119). Year, date of sampling, and age all significantly influenced mass. Nineteen males were recaptured at least twice during a single season. Mean rate of mass loss among these individuals was 2.5 ± 1.1 kg/day (range 0.7–4.6 kg/day). Body composition early in the breeding season, measured using tritiated water (N = 6), produced mean estimates of 51.6 ± 1.6% water, 29.3 ± 2.4% fat, 16.9 ± 0.7% protein, and 1.9 ± 0.2% ash. Time–depth recorders attached to three males indicated that they spent 84.7 ± 15.4% of their time hauled out on the surface of the ice during the breeding season. Each of these males was on the ice for a few days; they then spent a few hours at sea before returning to the ice surface. Mean dive depth was only 14.1 ± 3.2 m (maximum 66 m) and mean dive duration was only 1.7 ± 0.3 min (maximum 28 min). Extrapolating mean daily rates of body mass loss to encompass a 2.5-week breeding season, males would lose an average of 44 kg, which represents 14% of their mean body mass. Compared with values for males of other phocid species this value is conservative. It appears that the short breeding season among hooded seals is energetically advantageous for both sexes.

Vocal repertoire of the Saimaa ringed seal (Phoca hispida saimensis) during the breeding season

2009 ◽  
Vol 25 (4) ◽  
pp. 920-930 ◽  
Author(s):  
Anni Rautio ◽  
Marja Niemi ◽  
Mervi Kunnasranta ◽  
Ismo J. Holopainen ◽  
Heikki Hyvärinen
Keyword(s):  
Breeding Season ◽  
Ringed Seal ◽  
Vocal Repertoire ◽  
Phoca Hispida

The diving behavior of blue and fin whales: is dive duration shorter than expected based on oxygen stores?

2001 ◽  
Vol 129 (4) ◽  
pp. 797-809 ◽  
Author(s):  
Donald A Croll ◽  
Alejandro Acevedo-Gutiérrez ◽  
Bernie R Tershy ◽  
Jorge Urbán-Ramı́rez
Keyword(s):  
Dive Duration ◽  
Diving Behavior ◽  
Oxygen Stores ◽  
Fin Whales

Oxygen stores and aerobic dive limit of ringed seals (Phoca hispida)

1992 ◽  
Vol 70 (3) ◽  
pp. 458-461 ◽  
Author(s):  
Christian Lydersen ◽  
Morten Skrede Ryg ◽  
Mike Osborne Hammill ◽  
Peter James O'Brien
Keyword(s):  
Ringed Seal ◽  
Composition Analysis ◽  
Phoca Hispida ◽  
Free Living ◽  
Weddell Seals ◽  
Lung Capacity ◽  
Ringed Seals ◽  
Aerobic Dive Limit ◽  
Oxygen Stores ◽  
Average Adult

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 literature on maximum breathhold capacity and observed maximum dive times of ringed and Weddell seals (Leptonychotes weddellii), the maximum breathhold capacity of adult ringed seals was suggested to be 26.1 min.

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.

Heart rates and diving behavior of leatherback sea turtles in the eastern pacific ocean

1999 ◽  
Vol 202 (9) ◽  
pp. 1115-1125 ◽  
Author(s):  
A.L. Southwood ◽  
R.D. Andrews ◽  
M.E. Lutcavage ◽  
F.V. Paladino ◽  
N.H. West ◽  
...  
Keyword(s):  
Heart Rate ◽  
Sea Turtles ◽  
Dive Depth ◽  
Dive Duration ◽  
Diving Behavior ◽  
Leatherback Turtles ◽  
Heart Rates ◽  
The Mean ◽  
Leatherback Sea Turtles ◽  
Mean Heart Rate

Heart rates and diving behavior of leatherback sea turtles (Dermochelys coriacea) were monitored at sea during the internesting interval. Instruments that recorded the electrocardiogram and the depth and duration of dives were deployed on six female leatherback turtles as they laid eggs at Playa Grande, Costa Rica. Turtles dived continually for the majority of the internesting interval and spent 57–68 % of the time at sea submerged. Mean dive depth was 19+/−1 m (mean +/− s.d.) and the mean dive duration was 7.4+/−0.6 min. Heart rate declined immediately upon submergence and continued to fall during descent. All turtles showed an increase in heart rate before surfacing. The mean heart rate during dives of 17.4+/−0.9 beats min-1 (mean +/− s.d.) was significantly lower than the mean heart rate at the surface of 24.9+/−1.3 beats min-1 (P<0.05). Instantaneous heart rates as low as 1.05 beats min-1 were recorded during a 34 min dive. The mean heart rate over the entire dive cycle (dive + succeeding surface interval; 19.4+/−1.3 beats min-1) was more similar to the heart rate during diving than to the heart rate at the surface. Although dive and surface heart rates were significantly different from each other, heart rates during diving were 70 % of heart rates at the surface, showing that leatherback turtles do not experience a dramatic bradycardia during routine diving.

Testing predictions of optimal diving theory using animal-borne video from harbour seals (Phoca vitulina concolor)

2014 ◽  
Vol 92 (4) ◽  
pp. 309-318 ◽  
Author(s):  
Susan G. Heaslip ◽  
W. Don Bowen ◽  
Sara J. Iverson
Keyword(s):  
Nova Scotia ◽  
Temporal Pattern ◽  
Dive Depth ◽  
Dive Duration ◽  
Phoca Vitulina ◽  
Encounter Rate ◽  
Harbour Seals ◽  
Wide Range ◽  
Oxygen Stores ◽  
Free Ranging

Optimal diving theory predicts that animals make decisions that maximize their foraging profitability subject to the constraint of oxygen stores. We examined the temporal pattern of prey encounters within a dive from concurrently collected dive data and animal-borne video from a free-ranging pinniped to test predictions of optimal diving theory. Crittercams were deployed on 32 adult male harbour seals (Phoca vitulina concolor De Kay, 1842) at Sable Island, Nova Scotia, Canada, for 3 days each. Deployments resulted in approximately 3 h of video per seal and a total of 2275 capture attempts for 1474 prey encounter events recorded. We found support for seven of the nine selected predictions of optimal diving theory. As predicted, prey encounters increased with bottom duration; dive duration increased with dive depth; and travel duration, bottom duration, and percent bottom duration decreased over a wide range of travel durations. Descent duration did increase with dive depth, and seals terminated dives earlier when no prey were encountered and when prey were encountered later in a dive. Contrary to prediction, bottom duration did not increase and then decrease for short travel durations and dives were not terminated earlier when travel durations were short and prey encounter rate was low.

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