Interestingly, the grey seals appeared afraid of the live fish, with grey seal Sten swimming rapidly away from the artificial kelp when realizing that live fish was offered. Grey seal Liivi sometimes caught the live fish, but spat it out if she got a hold of it. None of the grey or harbour seals ingested a live fish during the entire study. This was the complete opposite behaviour of the fur seals, which searched for, chased and ingested the live fish with no apparent fear at all. Even the young fur seal Timjan, who was still nursing at the time, chased the live fish around the enclosure, although not ingesting the fish if she got a hold of it
The results show that both of the grey seals were engaged in stereotypic pattern swimming during the pre- treatment baseline observations. Both grey seals significantly decreased the amount of pattern swimming in the mornings after the treatment 1 sessions with dead fish. However, grey seal Liivi increased the amount of pattern swimming in the afternoons after live fish was flushed out.
When comparing the morning and afternoon behaviour of the grey seals after the dead fish sessions, there was significantly more pattern swimming in the afternoon. In the mornings the seals spent significantly more time resting and investigating the surroundings. None of the grey seals participated in the afternoon live fish sessions to any extent so that statistical analysis could be calculated. When the grey seals left the kelp area during the live fish sessions in treatment 1, the fur seals took the opportunity to participate.
In treatment 2, significantly more seals participated in the live fish sessions, and the time chasing the live fish was significantly longer than the time chasing the dead fish
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Last updated: 05/18/14