Use of signature whistles during separations and reunions by wild bottlenose dolphin mothers and infants

We examine the contexts and patterns of “signature” whistle production by wild bottlenose dolphin mother-infant pairs (Tursiops spp.) to gain insight into the functional significance of whistles. Results are based on focal observations and simultaneous recordings of underwater vocalizations. Whistles occur primarily when mother-infant pairs are separated, and the probability of whistles increases with distance of separation. The timing of whistles during separations varies, but whistles tend to be produced in repetitive series and are generally concentrated toward the later stages of the separation, i.e., during the process of reunion. Although we focused on infants, mothers do not appear to whistle during separations as frequently as infants. Infant whistles may function to facilitate reunions by conveying information to the mother concerning the infant's motivation to reunite and/or its location. Infant whistles could induce a cooperative response from the mother including approach, slowing to allow the infant to catch up or whistling. Highly individualized signature whistles may be particularly useful in a fission-fusion society in which individuals (mothers and infants as well as adults) join and leave temporary parties in a fluid manner, yet maintain consistent, long-term associations with particular individuals.

[1]  Melba C. Caldwell,et al.  10 – Review of the Signature-Whistle Hypothesis for the Atlantic Bottlenose Dolphin , 1990 .

[2]  V. Cockcroft,et al.  5 – Comments on Australian Bottlenose Dolphins and the Taxonomic Status of Tursiops aduncus (Ehrenberg, 1832) , 1990 .

[3]  C. K. Tayler,et al.  Social Organisation of Inshore Dolphins (Tursiops aduncus and sousa) in the Indian Ocean , 1973 .

[4]  D. K. Caldwell,et al.  The Whistle of the Atlantic Bottlenosed Dolphin (Tursiops truncatus)—Ontogeny , 1979 .

[5]  Randall S. Wells,et al.  The Social Structure of Free-Ranging Bottlenose Dolphins , 1987 .

[6]  J. Lilly,et al.  Sounds Emitted by the Bottlenose Dolphin , 1961, Science.

[7]  D. K. Caldwell,et al.  Vocalization of Naive Captive Dolphins in Small Groups , 1968, Science.

[8]  John W. Pepper,et al.  Sex Differences in Patterns of Association Among Indian Ocean Bottlenose Dolphins , 1992 .

[9]  J. Prescott,et al.  Observations of the sound production capabilities of the bottlenose porpoise: A study of whistles and clicks , 1962, Zoologica : scientific contributions of the New York Zoological Society..

[10]  D. K. Caldwell,et al.  STATISTICAL EVIDENCE FOR INDIVIDUAL SIGNATURE WHISTLES IN THE SPOTTED DOLPHIN, STENELLA PLAGIODON. , 1970 .

[11]  L. Ballance 13 – Residence Patterns, Group Organization, and Surfacing Associations of Bottlenose Dolphins in Kino Bay, Gulf of California, Mexico , 1990 .

[12]  R. Smolker,et al.  Loud Sounds During Feeding in Indian Ocean Bottlenose Dolphins , 1988 .

[13]  D. K. Caldwell,et al.  Individualized Whistle Contours in Bottle-nosed Dolphins (Tursiops truncatus) , 1965, Nature.

[14]  G. Peters,et al.  Acoustic Communication by Fissiped Carnivores , 1989 .

[15]  J. Altmann,et al.  Observational study of behavior: sampling methods. , 1974, Behaviour.

[16]  Randall S. Wells,et al.  Signature whistles of free-ranging bottlenose dolphins Tursiops truncatus: stability and mother-offspring comparisons , 1990, Behavioral Ecology and Sociobiology.

[17]  B. Würsig OCCURRENCE AND GROUP ORGANIZATION OF ATLANTIC BOTTLENOSE PORPOISES (TURSIOPS TRUNCATUS) IN AN ARGENTINE BAY , 1978 .

[18]  P. Tyack,et al.  Whistle repertoires of two bottlenosed dolphins, Tursiops truncatus: mimicry of signature whistles? , 1986, Behavioral Ecology and Sociobiology.

[19]  Bernd Würsig,et al.  The Photographic Determination of Group Size, Composition, and Stability of Coastal Porpoises (Tursiops truncatus) , 1977 .

[20]  John J. Dreher,et al.  Linguistic Considerations of Porpoise Sounds , 1961 .

[21]  Gary F. McCracken,et al.  Vocal recognition in mexican free-tailed bats: do pups recognize mothers? , 1992, Animal Behaviour.

[22]  M. C. Caldwell,et al.  STATISTICAL EVIDENCE FOR INDIVIDUAL SIGNATURE WHISTLES IN THE PACIFIC WHITESIDED DOLPHIN, LAGENORHYNCHUS OBLIQUIDENS , 1970 .

[23]  Robert Gisiner,et al.  California sea lion pups play an active role in reunions with their mothers , 1991, Animal Behaviour.

[24]  Heribert Hofer,et al.  Loud calling in a female-dominated mammalian society: I. Structure and composition of whooping bouts of spotted hyaenas, Crocuta crocuta , 1991, Animal Behaviour.

[25]  P. Brown,et al.  Vocal communication in the pallid bat, Antrozous pallidus. , 2010, Zeitschrift fur Tierpsychologie.

[26]  P. McArthur Mechanisms and development of parent-young vocal recognition in the piñon jay (Gymnorhinus cyanocephalus) , 1982, Animal Behaviour.

[27]  R. Connor,et al.  Two levels of alliance formation among male bottlenose dolphins (Tursiops sp.). , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[28]  F. Trillmich,et al.  Mutual Mother-Pup Recognition in Galápagos Fur Seals and Sea Lions: Cues Used and Functional Significance , 1981 .

[29]  R. Haven Wiley,et al.  5 – Adaptations for Acoustic Communication in Birds: Sound Transmission and Signal Detection , 1982 .

[30]  A. J. Gaston,et al.  Vocal recognition between parents and young of ancient murrelets, Synthliboramphus antiquus (Aves: Alcidae) , 1987, Animal Behaviour.

[31]  Y. Espmark Individual recognition by voice in reindeer mother-young relationship. Field observations and playback experiments. , 1971, Behaviour.

[32]  R. Connor,et al.  Habituated Dolphins (Tursiops sp.) in Western Australia , 1985 .

[33]  M. D. Beecher 2 – Development of Parent–Offspring Recognition in Birds , 1981 .

[34]  D. Hebb,et al.  Behavior of the captive bottle-nose dolphin, Tursiops truncatus. , 1948, Journal of comparative and physiological psychology.

[35]  A. F. McBride,et al.  Observations on Pregnancy, Parturition, and Postnatal Behavior in the Bottlenose Dolphin , 1951 .

[36]  G. Ross Comments on Australian bottlenose dolphins and the taxonomic status of Tursiops aduncus (Ehrenberg, 1982) , 1990 .