We also applied call detection and repertoire analysis to archived recordings from other studies of ringed and ribbon seal vocalizations.
We performed repertoire analysis on a large sample of ribbon seal calls detected during fall 2008 and found six types of vocalizations (Fig.
5a) are the most identifiable of ribbon seal vocalizations and made up about 20% of total calls.
5c) were the most commonly detected ribbon seal vocalization, representing 37% of total calls included in repertoire analysis.
5e) were the least common ribbon seal call detected and were found only during periods when the received level of their other calls was high.
They are the lowest-frequency ribbon seal vocalizations and have little frequency variation from start to end.
Ribbon seal calls occurred in highly stereotyped sequences.
Repertoire analysis was performed on a large sample of ribbon seal calls recorded by G.
Ribbon seal calls were detected during the open water period (AMSR-E mean ice cover of 0% within 20 km radius of recording site) on 17 days from 6 September through 24 October 2008, after which there were no further detections through the end of the recording period.
Among the ice-associated (pagophilic) seals, ringed seals, Phoca hispida, occur in all of these ice types, bearded seals, Erignathus barbatus, typically occur in all but the shorefast ice, while ribbon seals, Phoca fasciata, and spotted seals are generally found only in the ice front from February to late April.
Spotted seals are more numerous than ribbon seals on the southern side of the front towards the ice fringe, but the ratios reverse towards the northern edge near the pack ice (Burns, 1970).
The remainder consisted of ribbon seals (5%) and bearded and ringed seals (about 1% each).