Body mass and behaviour of stranded harbour seal (<em>Phoca
                        vitulina vitulina</em>) pups during the peak pupping season in Co. Down,
                    north-east Ireland

We studied changes in body mass and body composition of harbour seal pups from weaning to 5 – 6 weeks postweaning in June – August 1988 and 1989 on Sable Island, Canada. Known-age pups (n = 52) were captured at 3-day intervals from late lactation through about 40 days postweaning. Pups were weaned, on average, at 24.1 ± 0.44 days (mean ± SE) postpartum at a body mass of 24.9 ± 0.45 kg. There were no significant differences between years or sexes in the age and mass at weaning or in the rate of mass loss during the postweaning period. The duration of the postweaning fast averaged from 15 – 17 days as assessed by stomach lavage. The rate of mass loss was independent of weaning mass. At weaning, pups contained an average of 47.7% water and 32.8% fat, based on deuterium oxide dilution. During the first 14 days postweaning, the estimated body composition of pups did not change, despite the loss of body mass. Over the next 26 days, the estimated percent body water increased to about 63% and body fat declined to about 12%. The average energy density of harbour seal pups at weaning was low (16.3 kJ/g) compared with that of other phocids (17.7 – 22.2 kJ/g). This low energy density at weaning may reflect the highly aquatic and precocial development of harbour seal pups.

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The effect of maternal age and other factors on birth mass in the harbour seal

Canadian Journal of Zoology ◽

10.1139/z94-002 ◽

1994 ◽

Vol 72 (1) ◽

pp. 8-14 ◽

Cited By ~ 49

Author(s):

W. D. Bowen ◽

O. T. Oftedal ◽

D. J. Boness ◽

S. J. Iverson

Keyword(s):

Nova Scotia ◽

Developmental Stage ◽

Body Mass ◽

Maternal Age ◽

Phoca Vitulina ◽

Harbour Seal ◽

Birth Date ◽

Young Mothers ◽

Maternal Body ◽

Harbour Seals

We studied the effects of maternal age, maternal body mass at parturition, year of birth, birth date, pup sex, and developmental stage (as indicated by the presence of a foetal pelage called lanugo) on the birth mass of harbour seals (Phoca vitulina) on Sable Island, Nova Scotia, Canada. Between 1987 and 1992, mass was obtained on 330 newborns and 259 of their mothers. Birth mass was significantly correlated with maternal mass (r = 0.42 for male pups; r = 0.32 for female pups). Among pups that had shed their lanugo, males were significantly heavier at birth (11.4 ± 0.09 kg, n = 107) than females (10.9 ± 0.09, n = 99). Birth mass increased significantly with maternal age (n = 71, range 4–12 years) even after the effects of maternal mass and pup sex were statistically removed. Mean birth mass varied significantly among years, from 10.5 to 11.5 kg. Newborns averaged 12.8% of maternal mass at parturition (84.8 ± 0.49 kg). Most (84%) pups had shed their lanugo before birth. Pups born with extensive lanugo were born earlier in the season and weighed about 20% less than pups born without lanugo. These data suggest that pups born with lanugo may be less developed than pups that had shed their foetal coat. Young mothers (4 and 5 years old) produced most of the underweight, lanugo-covered pups.

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Vitamin A physiology in the precocious harbour seal (Phoca vitulina): a tissue-based biomarker approach

Canadian Journal of Zoology ◽

10.1139/z02-152 ◽

2002 ◽

Vol 80 (9) ◽

pp. 1511-1519 ◽

Cited By ~ 19

Author(s):

Lizzy Mos ◽

Peter S Ross

Keyword(s):

Vitamin A ◽

Marine Mammals ◽

Relevant Information ◽

Phoca Vitulina ◽

Retinyl Palmitate ◽

Harbour Seal ◽

Natural Processes ◽

Reproductive Endocrine ◽

Positive Correlations ◽

Free Ranging

Vitamin A is a nutrient essential to all mammals for growth and development, as well as for the maintenance of reproductive, endocrine, and immune systems. Environmental contaminant-related disruption of vitamin A has been observed in many wildlife species and can therefore be used as a biomarker of toxic effects. However, the natural processes regulating vitamin A uptake, storage, and distribution among compartments are poorly understood in marine mammals. In this study, 20 young healthy harbour seals (Phoca vitulina) were captured to establish a compartment-based model providing a foundation for a mechanistic understanding of vitamin A physiology and disruption. Vitamin A (retinol, retinyl palmitate, and (or) retinoic acid) was quantified in blood plasma and in biopsy samples of liver, blubber, and skin. Although the highest concentrations of vitamin A were found in liver, blubber represents a more important storage depot, with an estimated 66% of the total retinoid content of the compartments measured. We suggest that vitamin A physiology in the precocious harbour seal has evolved to deal with high vitamin A availability during a short nursing period and to sustain growth during the postweaning fast. Positive correlations in vitamin A concentrations among liver, blubber, and skin support the use of less invasive biopsy sampling of just blubber or skin, which can provide physiologically relevant information in biomarker studies of free-ranging marine mammals.

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Trace metal accumulation in hair and skin of the harbour seal, Phoca vitulina

Marine Pollution Bulletin ◽

10.1016/0025-326x(93)90126-5 ◽

1993 ◽

Vol 26 (3) ◽

pp. 152-155 ◽

Cited By ~ 26

Author(s):

C. Wenzel ◽

D. Adelung ◽

H. Kruse ◽

O. Wassermann

Keyword(s):

Trace Metal ◽

Metal Accumulation ◽

Phoca Vitulina ◽

Harbour Seal

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Deiminated proteins and extracellular vesicles as novel biomarkers in pinnipeds: Grey seal (Halichoerus gryptus) and harbour seal (Phoca vitulina)

Biochimie ◽

10.1016/j.biochi.2020.02.017 ◽

2020 ◽

Vol 171-172 ◽

pp. 79-90 ◽

Cited By ~ 4

Author(s):

Bergljót Magnadóttir ◽

Pinar Uysal-Onganer ◽

Igor Kraev ◽

Vilhjálmur Svansson ◽

Karl Skírnisson ◽

...

Keyword(s):

Extracellular Vesicles ◽

Phoca Vitulina ◽

Harbour Seal ◽

Grey Seal ◽

Novel Biomarkers

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Repetition enhances hearing detection thresholds in a harbour seal (Phoca vitulina)

Canadian Journal of Zoology ◽

10.1139/z93-120 ◽

1993 ◽

Vol 71 (5) ◽

pp. 926-932 ◽

Cited By ~ 22

Author(s):

S. D. Turnbull ◽

J. M. Terhune

Keyword(s):

White Noise ◽

Background Noise ◽

Phoca Vitulina ◽

Harbour Seal ◽

Detection Thresholds ◽

Noise Masking ◽

Phoca Groenlandica ◽

Hearing Thresholds ◽

Lower Detection ◽

Pinniped Species

Pure-tone hearing thresholds of a harbour seal (Phoca vitulina) were measured in air and underwater using behavioural psychophysical techniques. A 50-ms sinusoidal pulse was presented in both white-noise masked and unmasked situations at pulse repetition rates of 1, 2, 4, and 10/s. Test frequencies were 0.5, 1.0, 2.0, 4.0, and 8.0 kHz in air and 2.0, 4.0, 8.0, and 16.0 kHz underwater. Relative to 1 pulse/s, mean threshold shifts were −1, −3, and −5 dB at 2, 4, and 10 pulses/s, respectively. The threshold shifts from 1 to 10 pulses/s were significant (F = 12.457, df = 2,36, p < 0.001) and there was no difference in the threshold shifts between the masked and unmasked situations (F = 2.585; df = 1,50; p > 0.10). Broadband masking caused by meteorological or industrial sources will closely resemble the white-noise situation. At high calling rates, the numerous overlapping calls of some species (e.g., harp seal, Phoca groenlandica) present virtually continous "background noise" which also resembles the broadband white-noise masking situation. An implication of lower detection thresholds is that if a seal regularly repeats short vocalizations, the communication range of that call could be increased significantly (80% at 10 pulses/s). This could have important implications during the breeding season should storms or shipping noises occur or when some pinniped species become increasingly vocal and the background noise of conspecifics increases.

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Masked and unmasked pure tone detection thresholds of a harbour seal listening in air

Canadian Journal of Zoology ◽

10.1139/z91-287 ◽

1991 ◽

Vol 69 (8) ◽

pp. 2059-2066 ◽

Cited By ~ 18

Author(s):

J. M. Terhune

Keyword(s):

White Noise ◽

Pure Tone ◽

Phoca Vitulina ◽

Harbour Seal ◽

Optimal Conditions ◽

Vascular Changes ◽

Detection Thresholds ◽

Noise Masker ◽

Auditory Systems ◽

Tone Detection

In-air pure tone detection thresholds of a harbour seal (Phoca vitulina) were measured using behavioural psychophysical techniques. Thresholds dropped from about 70 dB re 20 μPa at 0.1 kHz to about 35 dB re 20 μ Pa at 4 kHz and then increased to about 45 dB re 20 μPa at 16 kHz. Increased sensitivities at 2 and 8 kHz, which have been reported in other pinnipeds, were not evident. In-air intensity detection thresholds averaged 32 dB above their underwater counterparts (1–16 kHz). Masking studies found the critical ratios at 0.25, 0.5, and 1 kHz to be 24, 15, and 21 dB, respectively (white noise masker). From 0.2 to 1.5 kHz, bandwidths 20 dB below the level of pure tone maskers were 0.16–0.18 kHz. Circumstantial evidence suggests the possibility that blood vascular changes associated with diving might also influence the sensitivity of the auditory systems of seals. Under optimal conditions, a pup's airborne cries may be detected by its mother at ranges of 1 km or more.

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