Behavioral and physiological reactions of arctic seals during under-ice pilotage
One spotted seal (Phoca largha) and two ringed seals (Phoca hispida) were studied in experiments designed to determine which sensory modalities were employed in pilotage from one under-ice breathing hole to another. Breathing holes were drilled in the ice of a frozen freshwater pond and a lake near...
| Published in: | Canadian Journal of Zoology |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1989
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/z89-354 http://www.nrcresearchpress.com/doi/pdf/10.1139/z89-354 |
| Summary: | One spotted seal (Phoca largha) and two ringed seals (Phoca hispida) were studied in experiments designed to determine which sensory modalities were employed in pilotage from one under-ice breathing hole to another. Breathing holes were drilled in the ice of a frozen freshwater pond and a lake near Fairbanks, Alaska. Holes were located 22–150 m apart. Tethered seals swimming without blindfolding located holes when they chanced to swim within visual detection distance. Blindfolded seals responded to acoustic signals. Tactile sensitivity of the vibrissae was used by blindfolded seals in the immediate vicinity of a hole to which they had been attracted by an acoustic cue. Responses of a juvenile ringed seal did not differ fundamentally from those of an adult of the same species nor from those of the spotted seal. The results indicate that seals relied upon a sensory hierarchy for locating breathing holes: vision, audition, and vibrissal sense. Heart rate was recorded during voluntary dives of the younger ringed seal at 2 and 3 years of age. Profound diving bradycardia was observed, suggesting that a highly developed diving response is routinely invoked by seals of relatively small body size during under-ice excursions. |
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