Winter Foraging by Common Seals (Phoca vitulina) in Relation to Food Availability in the Inner Moray Firth, N.E. Scotland

10.2307/5460 ◽  
1991 ◽  
Vol 60 (1) ◽  
pp. 283 ◽  
Author(s):  
P.M. Thompson ◽  
G.J. Pierce ◽  
J.R.G. Hislop ◽  
D. Miller ◽  
J.S.W. Diack
Keyword(s):  
Food Availability ◽  
Phoca Vitulina ◽  
Winter Foraging ◽  
Moray Firth

Seasonal variation in the diet of common seals (Phoca vitulina) in the Moray Firth area of Scotland

1991 ◽  
Vol 223 (4) ◽  
pp. 641-652 ◽  
Author(s):  
G. J. Pierce ◽  
P. M. Thompson ◽  
A. Miller ◽  
J. S. W. Diack ◽  
D. Miller ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Phoca Vitulina ◽  
Moray Firth

Prey selection by harbour seals, Phoca vitulina, in relation to variations in prey abundance

1997 ◽  
Vol 75 (9) ◽  
pp. 1508-1518 ◽  
Author(s):  
Dominic J. Tollit ◽  
Paul M. Thompson ◽  
Simon P. R. Greenstreet
Keyword(s):  
Diet Composition ◽  
Prey Size ◽  
Prey Selection ◽  
Phoca Vitulina ◽  
Correction Factors ◽  
Fish Prey ◽  
Size Selection ◽  
Harbour Seals ◽  
Moray Firth ◽  
Time Periods

This study compared the composition of the diet of harbour seals (Phoca vitulina) feeding in the Moray Firth, Scotland, with the abundance of their fish prey estimated from dedicated fishery surveys in January 1992 and 1994 and June 1992. Prey-size selection was also examined in these three time periods and in January 1991. In each period, the most abundant fish species contributed most to the diet. However, the relative abundances of the remaining species in the sea showed little similarity to their contribution to the seals' diet. Diet composition was almost totally dominated by either pelagic species or species dwelling on or strongly associated with the seabed, depending upon the relative abundance of pelagic schooling prey. Most fish consumed were 10–16 cm in length, although larger cod and herring were taken. With the exception of cod, the extent of size selection was dependent upon the use of correction factors that accounted for otolith erosion due to digestion.

The effect of weather conditions on harbour seal (Phoca vitulina) haulout behaviour in the Moray Firth, northeast Scotland

1996 ◽  
Vol 74 (10) ◽  
pp. 1806-1811 ◽  
Author(s):  
Kate Grellier ◽  
Paul M. Thompson ◽  
Heather M. Corpe
Keyword(s):  
Significant Relationship ◽  
Seasonal Changes ◽  
Negative Relationship ◽  
Weather Conditions ◽  
Phoca Vitulina ◽  
Effect Of Temperature ◽  
Harbour Seals ◽  
Moray Firth ◽  
A Site ◽  
The Relationship

Abundance data from a 6-year study (1988–1993) of harbour seals (Phoca vitulina) were used to control for seasonal changes in haulout behaviour and assess the effect of temperature and other weather conditions on haulout numbers at a site in Scotland. A significant relationship between Julian day and haulout numbers was consistent between years. In some years, there was also a significant relationship between ambient temperature and haulout numbers, but examination of the residuals around the relationship between haulout numbers and Julian day revealed no evidence for a consistent effect of temperature, wind speed, or wind-chill adjusted temperatures. A weak negative relationship between haulout numbers and both precipitation and cloud cover did exist, but these variables explained little of the variation in seal numbers.

Evidence for a progressively earlier pupping season of the common seal (Phoca vitulina) in the Wadden Sea

2011 ◽  
Vol 92 (8) ◽  
pp. 1663-1668 ◽  
Author(s):  
N. Osinga ◽  
I. Pen ◽  
H.A. Udo de Haes ◽  
P.M. Brakefield
Keyword(s):  
Climate Change ◽  
Food Availability ◽  
Adaptive Response ◽  
Wadden Sea ◽  
Negative Impact ◽  
Phoca Vitulina ◽  
Region Analysis ◽  
Delayed Implantation ◽  
The Common ◽  
Sea Area

Common seals Phoca vitulina give birth in the Wadden Sea area during the summer months. We provide evidence that the pupping season has advanced in date in this region. Analysis of stranding dates of recently-born, orphaned pups admitted for rehabilitation, revealed a shift of, on average, 0.88 days per year over the period 1974–2008, yielding a total advance of 26 days. Although the pupping season has become progressively earlier, there were no indications of any negative impact on the weight of the pups, nor was there an increase in the proportion of seals with a lanugo coat. These observations suggest that the most likely explanation for the change in phenology of the pupping season is a corresponding change in the timing of cessation of the period of delayed implantation. It is suggested that shifts in phenology could reflect an adaptive response of the animals to altered local circumstances. The latter may in turn be induced by larger scale phenomena such as food availability or climate change.

Prevalence and intensity of the ectoparasite Echinophthirius horridus on harbour seals (Phoca vitulina): effects of host age and inter-annual variability in host food availability

Parasitology ◽  
1998 ◽  
Vol 117 (4) ◽  
pp. 393-403 ◽  
Author(s):  
P. M. THOMPSON ◽  
H. M. CORPE ◽  
R. J. REID
Keyword(s):  
Food Availability ◽  
Negative Correlation ◽  
Significant Negative Correlation ◽  
Phoca Vitulina ◽  
Host Age ◽  
Intensity Of Infection ◽  
Geographical Differences ◽  
Harbour Seals ◽  
Sucking Lice ◽  
Annual Changes

The epidemiology of the sucking lice Echinophthirius horridus was studied over a 4 year period in which their harbour seal hosts experienced marked inter-annual changes in food availability. Prevalence and intensity of infection varied in relation to host age but not sex. Burdens were highest on immature seals, but both prevalence and intensity of infection were significantly higher in years when food availability was low. Observed intra-population variations in ectoparasite dynamics suggested that reported geographical differences in the prevalence of E. horridus may have resulted from methodological differences. In contrast to previous studies of other pinnipeds, lice were also absent on weaned pups, suggesting that E. horridus is transferred horizontally. No significant differences were found in the haematological parameters of infected and uninfected hosts. Nevertheless, there was a significant negative correlation between intensity of infection and several erythrocyte parameters, suggesting that high burdens of lice may compromise diving ability.

Hearing Thresholds of Two Harbor Seals (Phoca vitulina) for Helicopter Dipping Sonar Signals (1.3-1.4 kHz)

2019 ◽  
Vol 45 (3) ◽  
pp. 349-355
Author(s):  
Ronald A. Kastelein ◽  
Robin Gransier ◽  
Marloe Brouwers ◽  
Lean Helder-Hoek
Keyword(s):  
Phoca Vitulina ◽  
Harbor Seals ◽  
Hearing Thresholds

Variation of Male–Male Aggression Patterns in Harbor Seals (Phoca vitulina)

2020 ◽  
Vol 46 (2) ◽  
pp. 119-123
Author(s):  
Anders Galatius ◽  
Jonas Teilmann ◽  
Jakob Tougaard ◽  
Rune Dietz
Keyword(s):  
Phoca Vitulina ◽  
Harbor Seals ◽  
Male Aggression
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