Behavioral Context of Call Production by Eastern North Pacific Blue Whales

We assessed the behavioral context of calls produced by blue whales Balaenoptera musculus off the California coast based on acoustic, behavioral, and dive data obtained through acoustic recording tags, sex determination from tissue sampling, and coordinated visual and acoustic observations. Approxim...

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Bibliographic Details
Main Authors: Oleson, Erin M, Calambokidis, John, Burgess, William C, McDonald, Mark A, LeDuc, Carrie A, Hildebrand, John A
Other Authors: CASCADIA RESEARCH COLLECTIVE OLYMPIA WA
Format: Text
Language:English
Published: 2007
Subjects:
Biological Oceanography
Acoustics
*AUDIO TONES
*BEHAVIOR
*WHALES
CALIFORNIA
CIRCADIAN RHYTHMS
COASTAL REGIONS
NORTH PACIFIC OCEAN
PATTERNS
SEX
SHALLOW DEPTH
BLUE WHALES
FORAGING
GROUP SIZE
SEX BIAS
SUCTION CUP TAGS
WHALE CALLS
WHALE SONGS
REPRINTS
Lone
Pacific
Balaenoptera musculus
Online Access:http://www.dtic.mil/docs/citations/ADA580707
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA580707
Description
Summary:We assessed the behavioral context of calls produced by blue whales Balaenoptera musculus off the California coast based on acoustic, behavioral, and dive data obtained through acoustic recording tags, sex determination from tissue sampling, and coordinated visual and acoustic observations. Approximately one-third of 38 monitored blue whales vocalized, with sounds categorized into 3 types: (1) low-frequency pulsed A and tonal B calls, in either rhythmic repetitive song sequences or as intermittent, singular calls; (2) downswept D calls; and (3) highly variable amplitude- or frequency-modulated calls. Clear patterns of behavior, sex, and group size are evident for some call types. Only males were documented producing AB calls, with song produced by lone, traveling blue whales, and singular AB calls were more typically produced by whales in pairs; D calls were heard from both sexes during foraging, commonly from individuals within groups. The sex bias evident in AB callers suggests that these calls probably play a role in reproduction, even though the calls are produced year-round. All calls are produced at shallow depth, and calling whales spend more time at shallow depths than non-calling whales, suggesting that a cost may be incurred during D calling as less time is spent feeding at deeper depths. This relationship between calling and depth may predict the traveling behavior of singing blue whales, as traveling whales do not typically dive to deep depths and therefore would experience little extra energetic cost related to the production of long repetitive song bouts while moving between foraging areas. Published in Marine Ecology Progress Series, v330, p269-284, 25 January 2007.

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