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Acoustic features involved in the neighbour-stranger vocal recognition process in male Australian fur seals

journal contribution
posted on 2008-09-01, 00:00 authored by J Tripovich, I Charrier, T Rogers, R Canfield, John ArnouldJohn Arnould
Many territorial species have the ability to recognise neighbours from stranger individuals. If the neighbouring individual is assumed to pose less of a threat, the territorial individual responds less and avoids unnecessary confrontations with familiar individuals at established boundaries, thus avoiding the costly energy expenditure associated with fighting. Territorial male Australian fur seals respond more to strangers than to neighbouring males. The present study evaluated which acoustic features were important in the neighbour–stranger recognition process in male Australian fur seals. The results reveal that there was an increase in response strength or intensity from males when they heard more bark units, indicating the importance of repetition to detect a caller. However, lengthening and shortening the inter-unit spaces, (i.e. changing the rhythm of the call) did not appear to significantly affect an animal's response. In addition, the whole frequency spectrum was considered important to recognition with results suggesting that they may vary in their importance. A call containing the dominant and surrounding harmonics was considered important to a male's ability to recognise its neighbour. Furthermore, recognition occurs even with a partial bark, but males need to hear between 25 and 75% of each bark unit from neighbouring seals. Our study highlights which acoustic features induce stronger or weaker responses from territorial males, decoding the important features in neighbour–stranger recognition.

History

Journal

Behavioural processes

Volume

79

Issue

1

Pagination

74 - 80

Publisher

Elsevier BV

Location

Amsterdam, Netherlands

ISSN

0376-6357

eISSN

1872-8308

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2008, Elsevier B.V.