5. Acoustics and Social Behavior
241
of both species during interspecific conflict (Herzing 1996; Herzing and
Johnson 1997).
Many species utilize acoustic information from neighboring species
(Fagan 1981). Studies on the perception of the human voice by nonhuman
animals (as reviewed in Ralston and Herman 1989) indicate that speciesspecific processes are not necessary for the recognition of acoustic phonetic
segments. Two sympatric species as closely related as S. frontalis and
T truncatus may be able to decipher species-specific signaling and perhaps
use it functionally during mixed-species aggregations. Cross-species signal
content may be read across species boundaries utilizing specific sound parameters (Morton 1977). Cross-species overlap may allow messages and their
modulated information, to be decoded between species and might provid~
a research window for decoding information available to both species.
3.7 Nonvocal Acoustics Associated with
Behavioral Activity
S. frontalis use (1) tail-slaps as attention-getting mechanisms or in annoyance, (2) jaw claps in escalated aggression, (3) aerial displays during play
behavior and also during intra- and interspecific aggressive chases, (4)
bubble displays in the production of whistles (bubble trails) and in annoyance (full and half bubbles) and bubble rings (torus) during annoyance or
aggressive contexts, and (5) in-air vocalizations, including the chuff (an
explosive exhalation) during annoyance and raspberry (a constricted exhalation) in interspecies affiliative contexts. Although nonvocal by traditional
definition, these sounds provide acoustic signals and their prosodic features,
including rate, spacing, and frequency, may be conserved and available for
analysis.
Jaw claps have been noted in aggressive contexts for T truncatus
(Overstrom 1983; Herzing 1988) and interspecifically during the intimidation of subordinate dolphins by dominant conspecifics (Wood 1953). Sharp
puffs of air have been noted during signs of agitation by S. attenuata
(Pryor and Kang-Shallenberger 1991). Bubbles and bubble rings (torus) are
produced during aggressive interactions of S. attenuata (Pryor and Kang
1980) and during play activity of T truncatus (Marten et al. 1996).
Nonvocal impulse sounds, including sounds produced by slamming of
body parts, cavitational movements, percussive thrashing during attempted
hits, closure of the jaw, and various aerial behaviors, have been described
spectrally and in behavioral contexts for multiple species (Marten et al.
1988) and during behavioral contexts including agitation and stress
(Caldwell et al. 1962; Norris and Dohl 1980; Pryor and Kang-Shallenberger
1991). Such signals are typically of a short time duration and may function
as supplemental or exclamatory signals during activity, either from a
distance or in close proximity. Wild dolphins may be able to convey, as
241
of both species during interspecific conflict (Herzing 1996; Herzing and
Johnson 1997).
Many species utilize acoustic information from neighboring species
(Fagan 1981). Studies on the perception of the human voice by nonhuman
animals (as reviewed in Ralston and Herman 1989) indicate that speciesspecific processes are not necessary for the recognition of acoustic phonetic
segments. Two sympatric species as closely related as S. frontalis and
T truncatus may be able to decipher species-specific signaling and perhaps
use it functionally during mixed-species aggregations. Cross-species signal
content may be read across species boundaries utilizing specific sound parameters (Morton 1977). Cross-species overlap may allow messages and their
modulated information, to be decoded between species and might provid~
a research window for decoding information available to both species.
3.7 Nonvocal Acoustics Associated with
Behavioral Activity
S. frontalis use (1) tail-slaps as attention-getting mechanisms or in annoyance, (2) jaw claps in escalated aggression, (3) aerial displays during play
behavior and also during intra- and interspecific aggressive chases, (4)
bubble displays in the production of whistles (bubble trails) and in annoyance (full and half bubbles) and bubble rings (torus) during annoyance or
aggressive contexts, and (5) in-air vocalizations, including the chuff (an
explosive exhalation) during annoyance and raspberry (a constricted exhalation) in interspecies affiliative contexts. Although nonvocal by traditional
definition, these sounds provide acoustic signals and their prosodic features,
including rate, spacing, and frequency, may be conserved and available for
analysis.
Jaw claps have been noted in aggressive contexts for T truncatus
(Overstrom 1983; Herzing 1988) and interspecifically during the intimidation of subordinate dolphins by dominant conspecifics (Wood 1953). Sharp
puffs of air have been noted during signs of agitation by S. attenuata
(Pryor and Kang-Shallenberger 1991). Bubbles and bubble rings (torus) are
produced during aggressive interactions of S. attenuata (Pryor and Kang
1980) and during play activity of T truncatus (Marten et al. 1996).
Nonvocal impulse sounds, including sounds produced by slamming of
body parts, cavitational movements, percussive thrashing during attempted
hits, closure of the jaw, and various aerial behaviors, have been described
spectrally and in behavioral contexts for multiple species (Marten et al.
1988) and during behavioral contexts including agitation and stress
(Caldwell et al. 1962; Norris and Dohl 1980; Pryor and Kang-Shallenberger
1991). Such signals are typically of a short time duration and may function
as supplemental or exclamatory signals during activity, either from a
distance or in close proximity. Wild dolphins may be able to convey, as