Grading, Discreteness, Redundancy, and Motivation-Structural Rules

Morton, Eugene S.

doi:10.1016/b978-0-08-092416-8.50015-2

Cited by 178 publications

(151 citation statements)

References 42 publications

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“…Sharng may improve the receiver's ability to identify environmental effects on a propagating signal, which may improve the receiver's ability to estimate the range to the signaler (Morton, 1982;Falls et al, 1982;McGregor et aI., 1983;Shy & Morton, 1986; but see Naguib, 1997Naguib, , 1998Wiley, 1998). Matched counter-callng occurs when a receiver responds to a signal by producing the same signal (Sugiura, 1993), and may provide a mea!1s for a respondent to direct a signal at the original caller (McGregor et aI., 1992).…”

Section: Discussionmentioning

confidence: 99%

“…I was also able to confirm that killer whale calls are directional at high frequencies, and show that this directionality strcture provides a potentially useful cue of the direction-of-movement of the signaler (chapter six). Call-type sharing by members of the same group may help receivers more accurately identify orientation and range-dependent effects on the signal (Morton, 1982).…”

Section: Discussionmentioning

confidence: 99%

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Maintaining contact : design and use of acoustic signals in killer whales, Orcinus orca

Miller¹

2000

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This thesis presents data on the structure and use of acoustic signals produced by free-ranging resident kiler whales. The analysis focuses on signal features that might be useful for animals to maintain contact and coordinate activities with preferred associates, including: distinctiveness by group or individual, call amplitude, and directionality cues that might cue the direction-of-movement of the signaler. Research was conducted in Haro and Johnstone Straits off Vancouver Island, British Columbia, where kiler whales have been the focus of a long-term photo-identification effort. Extensive previous research on this population has demonstrated stable kin-based matrilineal social groups and pod-specific calling behavior.Individually-distinctive markings and pigmentation patterns were used to identify groups or individuals from which sounds were recorded. Recordings from each of the three matrilineal groups composing pod Al were made when each subgroup was isolated from the two other subgroups. Analysis of call use and structure revealed subgroupspecificity that was qualitatively similar to previously observed differences between pods, although more subtle. This finding suggests that pod-specific callng arises primarly as a consequence of accumulated drift or divergence of calls between highly cohesive matrilineal subgroups as they gradually separate into different pods. A new towed aray beamforming system was developed to identify vocalizing killer whales concurrent with focal behavioral observations. Carefully positioning the aray relative to the animals and linking visual observations of whale position with the angle-of-arrival of sounds on the towed array allows reliable identification of signalers in many circumstances. Using this new system, a sample of 140 calls was recorded from identified individuals within W-pod to compare the call-type repertoires of individuals within a matrilineal subgroup. The three individuals composing W-pod shared at least four different call types and call-type 5 frequency did not differ by individual, suggesting each matrilineal group member uses the same call types in a similar fashion.To measure signal source levels, the range from the array to a signaler was calculated by triangulating the angles-of-arrival of the sound on two beamforming arrays towed in series. Source levels of 819 calls and 24 whistles were combined with a model of sound propagation and perception to estimate the maximum range at which another kiler whale could detect each sound in quiet conditions. The estimated maximum range of detectability of all sounds ranged from 4.5 to 26.2 km, suggesting killer whales can maintain acoustic contact with each other over long ranges. Whistles and variable calls have a smaller active space than stereotyped calls which appear to consist of two groups: long-and short-range call types with a mean estimated active space of 14.5 and 8.8 km, respectively. Directionality features of calls were described by recording sounds in front of, and behind, groups of animals a...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Maintaining contact : design and use of acoustic signals in killer whales, Orcinus orca

Miller¹

2000

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“…Staccatos may also obey motivational-structural rules (Morton 1982), and work as a mecha- nism for competition avoidance. In some primates, the degree of harshness and pitch of calls relates to tendencies of spatial proximity or spatial dispersion (Robinson 1982, Boinski 1991.…”

Section: Discussionmentioning

confidence: 99%

Vocal sequential exchanges and intragroup spacing in the Northern Muriqui Brachyteles arachnoides hypoxanthus

Mendes

Ades

2004

An. Acad. Bras. Ciênc.

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Sequential exchanges of vocalizations (staccatos and neighs) emitted by Northern MuriquisBrachyteles arachnoides hypoxanthus were recorded at the Biological Station of Caratinga, Minas Gerais State, Brazil. Staccatos and neighs containing larger proportion of short elements were preferentially produced during short-range exchanges; neighs, produced by a larger number of participants, were typical of long-range exchanges. Staccatos emitted by animals feeding in a dispersed manner contained a larger proportion of tonal elements than those emitted by muriquis feeding in a cohesive manner. Sequential exchanges seem thus to be constituted by two inter-related subsystems of calls that aid muriquis to coordinate intragroup spacing, despite the poor visibility of the habitat.

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“…For example, spectral peaks present in the bee note might be equal at a distance of 80 m in one environment, but not in a different habitat. Many environmental variables affect how songs attenuate and reverberate during transmission (Richards & Wiley, 1980;Wiley & Richards, 1978, 1982. Because most of the conditions that affect propagation along a direct path will also affect transmission of reverberated echoes along indirect paths, habitat-dependent effects on attenuation will be correlated with habitat-dependent effects on reverberation.…”

Section: Perception Of Changes In Singer Distancementioning

confidence: 99%

“…Birds clearly can make use of amplitude cues to judge singer distance in some circumstances (Nelson, 2000;Radziwon et al, 2011). Amplitude cues are less reliable than other distance cues because of amplitude variations caused by factors other than source distance, such as differences in source levels, atmospheric conditions, and height of the singer (Morton, 1982;Wiley & Richards, 1978, 1982. Chickadees trained to discriminate songs recorded from different distances varied in their use of amplitude cues, with some individuals using them and others ignoring them (Phillmore et al, 1998).…”

Section: Cues To Singer Distancementioning

confidence: 99%