title: Species-specific beaked whale echolocation signals.
abstract: Beaked whale echolocation signals are mostly frequency-modulated (FM) upsweep pulses and appear to be species specific. Evolutionary processes of niche separation may have driven differentiation of beaked whale signals used for spatial orientation and foraging. FM pulses of eight species of beaked whales were identified, as well as five distinct pulse types of unknown species, but presumed to be from beaked whales. Current evidence suggests these five distinct but unidentified FM pulse types are also species-specific and are each produced by a separate species. There may be a relationship between adult body length and center frequency with smaller whales producing higher frequency signals. This could be due to anatomical and physiological restraints or it could be an evolutionary adaption for detection of smaller prey for smaller whales with higher resolution using higher frequencies. The disadvantage of higher frequencies is a shorter detection range. Whales echolocating with the highest frequencies, or broadband, likely lower source level signals also use a higher repetition rate, which might compensate for the shorter detection range. Habitat modeling with acoustic detections should give further insights into how niches and prey may have shaped species-specific FM pulse types.
authors: Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093-0205, USA. sbaumann@ucsd.edu
authors: Simone
authors: S
authors: Baumann-Pickering
authors: Mark A
authors: MA
authors: McDonald
authors: Anne E
authors: AE
authors: Simonis
authors: Alba
authors: A
authors: Solsona Berga
authors: Karlina P B
authors: KP
authors: Merkens
authors: Erin M
authors: EM
authors: Oleson
authors: Marie A
authors: MA
authors: Roch
authors: Sean M
authors: SM
authors: Wiggins
authors: Shannon
authors: S
authors: Rankin
authors: Tina M
authors: TM
authors: Yack
authors: John A
authors: JA
authors: Hildebrand
mesh_terms: D000162:Acoustics; D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D004455:Echolocation; D005247:Feeding Behavior; D011235:Predatory Behavior; D013018:Sound Spectrography; D013045:Species Specificity; D013997:Time Factors; D014828:Vocalization, Animal; D014907:Whales / Q000502:physiology*