title: Short first click intervals in echolocation trains of three species of deep diving odontocetes.
abstract: All odontocetes produce echolocation clicks as part of their vocal repertoire. In this paper the authors analysed inter-click-intervals in recordings from suction cup tags with a focus on the first inter-click interval of each click train. The authors refer to shorter first inter-click intervals as short first intervals (SFIs). The authors found that the context of SFI occurrence varies across three deep-diving species. In Blainville's beaked whales, 87% of click trains that were preceded by a terminal buzz started with SFIs. In Cuvier's beaked whales, only sub-adult animals produced notable amounts of SFIs. In contrast, sperm whales were much more likely to produce SFIs on the first click train of a dive. While the physiological and/or behavioural reasons for SFI click production are unknown, species differences in their production could provide a window into the evolution of odontocete echolocation.
authors.affiliation: Bahamas Marine Mammal Research Organisation, P.O. Box AB-20714, Marsh Harbour, Abaco, Bahamas.
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Dunn
authors.affiliation: Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, Fife KY16 8LB, Scotland.
authors.forename: Peter
authors.initials: P
authors.lastname: Tyack
authors.affiliation: Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, Fife KY16 8LB, Scotland.
authors.forename: Patrick J O
authors.initials: PJ
authors.lastname: Miller
authors.affiliation: Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, Fife KY16 8LB, Scotland.
authors.forename: Luke
authors.initials: L
authors.lastname: Rendell