Correction to: Serum biochemistry and haematology in wild and captive bearded seals (Erignathus barbatus) from Svalbard, Norway

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.

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Bearded seal (Erignathus barbatus) vocalizations across seasons and habitat types in Svalbard, Norway

Polar Biology ◽

10.1007/s00300-021-02874-9 ◽

2021 ◽

Author(s):

Samuel M. Llobet ◽

Heidi Ahonen ◽

Christian Lydersen ◽

Jørgen Berge ◽

Rolf Ims ◽

...

Keyword(s):

Sea Ice ◽

Generalized Additive Models ◽

Extended Period ◽

Ice Cover ◽

High Arctic ◽

Additive Models ◽

Breeding Habitat ◽

Breeding Populations ◽

Erignathus Barbatus ◽

Bearded Seals

AbstractMale bearded seals (Erignathus barbatus) use vocal displays to attract females and to compete with other males during the mating season. This makes it possible to monitor breeding populations of this species using passive acoustic monitoring (PAM). This study analysed year-round acoustic data records from AURAL instruments in Svalbard (Norway) to investigate seasonal variation in the acoustic presence of male bearded seals and the phenology of different call types (long, step and sweep trills) at three sites representing a variety of habitats with varied ice conditions. Male bearded seals vocalized for an extended period at a drift-ice site (Atwain; January–July) north of Spitsbergen, while the vocal season was shorter at a High Arctic land-fast-ice site (Rijpfjorden; February–June) and shorter yet again at a west-coast site that has undergone dramatic reductions in sea ice cover over the last 1.5 decades (Kongsfjorden; April–June). Generalized Additive Models showed marked seasonal segregation in the use of different trill types at Atwain, where call rates reached 400 per h, with long trills being the most numerous call type. Modest segregation of trill types was seen at Rijpfjorden, where call rates reached 300 per h, and no segregation occurred in Kongsfjorden (peak call rate 80 per h). Sea ice cover was available throughout the vocal season at Atwain and Rijpfjorden, while at Kongsfjorden peak vocal activity (May–June) occurred after the sea ice disappeared. Ongoing climate warming and sea ice reductions will likely increase the incidence of such mismatches and reduce breeding habitat for bearded seals.

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Birth-Site Characteristics and Prenatal Molting in Bearded Seals (Erignathus barbatus)

Journal of Mammalogy ◽

10.2307/1382789 ◽

1996 ◽

Vol 77 (4) ◽

pp. 1085-1091 ◽

Cited By ~ 30

Author(s):

K. M. Kovacs ◽

C. Lydersen ◽

I. Gjertz

Keyword(s):

Site Characteristics ◽

Erignathus Barbatus ◽

Bearded Seals

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Winter Distribution of Bearded Seals (Erignathus barbatus) in the Penny Strait Area, Northwest Territories, as Determined by Underwater Vocalizations

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f90-123 ◽

1990 ◽

Vol 47 (6) ◽

pp. 1071-1076 ◽

Cited By ~ 20

Author(s):

Holly J. Cleator ◽

Ian Stirling

Keyword(s):

Northwest Territories ◽

Absolute Number ◽

Bearded Seal ◽

Vocal Behaviour ◽

Winter Distribution ◽

Odobenus Rosmarus ◽

Erignathus Barbatus ◽

Break Up ◽

A Site ◽

Bearded Seals

Vocalization surveys conducted in Penny Strait, Northwest Territories, indicated that before ice break-up, bearded seals (Erignathus barbatus) preferred regions of less stable ice where break-up occurred early and avoided stable, landfast ice or areas heavily used by walruses (Odobenus rosmarus). Water depth did not appear to influence distribution. Numbers of calls increased between mid-April and early June, probably because of an increase in rate of calling by individual seals. Vocalization surveys can be used to separate preferred habitats from unsuitable ones. Using a single hydrophone and our current understanding of bearded seal vocal behaviour, it is not possible to determine the absolute number of bearded seals at or near a site using vocalizations. However, it is possible to measure the relative abundance of seals for spatial and temporal comparisons.

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Auditory biology of bearded seals (Erignathus barbatus)

Polar Biology ◽

10.1007/s00300-020-02736-w ◽

2020 ◽

Vol 43 (11) ◽

pp. 1681-1691 ◽

Cited By ~ 1

Author(s):

Jillian M. Sills ◽

Colleen Reichmuth ◽

Brandon L. Southall ◽

Alex Whiting ◽

John Goodwin

Keyword(s):

Erignathus Barbatus ◽

Bearded Seals

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Habitat selection and seasonal movements of young bearded seals (Erignathus barbatus) in the Bering Sea

PLoS ONE ◽

10.1371/journal.pone.0192743 ◽

2018 ◽

Vol 13 (2) ◽

pp. e0192743 ◽

Cited By ~ 9

Author(s):

Michael F. Cameron ◽

Kathryn J. Frost ◽

Jay M. Ver Hoef ◽

Greg A. Breed ◽

Alex V. Whiting ◽

...

Keyword(s):

Habitat Selection ◽

Bering Sea ◽

Seasonal Movements ◽

Erignathus Barbatus ◽

The Bering Sea ◽

Bearded Seals

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Pitch separation as a possible jamming-avoidance mechanism in underwater calls of bearded seals (Erignathus barbatus)

Canadian Journal of Zoology ◽

10.1139/z99-067 ◽

1999 ◽

Vol 77 (7) ◽

pp. 1025-1034 ◽

Cited By ~ 11

Author(s):

John M Terhune

Keyword(s):

Nearest Neighbour ◽

Call Duration ◽

Jamming Avoidance ◽

Erignathus Barbatus ◽

Bearded Seals

Bearded seals (Erignathus barbatus) produce simultaneous loud, long, narrowband underwater trills. It is likely that calls separated by 1/3 octave will not mask each other. Three call (trill) types were identified. Pitch separations between nearest-neighbour calls were measured by sampling at 1-s intervals. Calls spanned 5 octaves and were centred near 1 kHz. Mean pitch separations decreased significantly as the number of simultaneous calls increased from 2 to 9-11, but remained relatively constant at about 0.3 octave at higher numbers of simultaneous calls. For 2-12 simultaneous calls, the pitch separations between 0.0 and 0.4 octave were fewer than random. Proportions of the three trill types did not change as the numbers of simultaneous calls increased. All three call types had fewer pitch separations below 1/3 octave than between 1/3 and 2/3 octave. No relationship was found between pitch separation and call duration. Differences in starting pitch and the regular decline in pitch throughout most calls ensured that mean pitch separations of >1/3 octave were maintained even when many calls occurred simultaneously. Bearded seals may use pitch separation as a jamming-avoidance mechanism.

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