2001. Connor RC, Heithaus MR and Barre LM. Complex social structure, alliance stability and mating access in a bottlenose dolphin 'super-alliance. Proceedings of the Royal Society of London, Series B. in press.

2001. Connor RC.Social relationships in a big-brained aquatic mammal. In: Dugatkin LA. (ed), Model Systems in Behavioral Ecology . Princeton University Press.

2001. Mann J and Sargeant B. Like mother, like calf: The ontogeny of foraging specializations in wild bottlenose dolphins .In: Fragaszy D and Perry S. (eds), The Biology of Traditions. Cambridge University Press.

2000. Connor RC, Heithaus MR, Berggren P and Miksis JL.'Kerplunking': Surface fluke-splashes during shallow water bottom foraging by bottlenose dolphins. Marine Mammal Science. 16: 646-653.

In Shark Bay, Western Australia, bottlenose dolphins (T.aduncus, following LeDuc et al. 1999) commonly forage on or near the bottom in shallow water (<4m). While foraging in the shallows, individuals often engage in "bottom grubbing," in which they orient toward, and poke their rostra into, the sea grass. Dolphins foraging in this manner are sometimes observed to chase, surface with, or throw a fish. While foraging over offshore flats (1.5-2.5m), bottom-grubbing individuals sometimes perform peculiar fluke-slaps that produce a 1-3.5m high splash of water and an audible "kerplunk" sound in air. Observations made during 1994-1995 suggest that such "kerplunks" may aid in the location or capture of fish by eliciting a startle response in hiding fish, revealing their location to the dolphin above.

2000. Mann J, Connor RC, Barre LM and Heithaus MR. Female reproductive success in wild bottlenose dolphins (Tursiops sp.): Life history, habitat, provisioning, and group size effects. Behavioral Ecology. 11: 210-219.

This study examines factors influencing female reproductive success in wild bottlenose dolphins (Tursiops sp.) in Shark Bay, Australia. Eighty-three females and their 142 calves were surveyed between 1988-1998 (3,457 surveys); 42 calves were also observed during focal follows for 1,330 hrs. Calf mortality is 44% by age 3 (N=110). Reproduction is moderately seasonal, peaking October-December. Length of interval to conception following calf loss inversely correlates with month of the year (r=-.53, p<.05), favoring within season births (p<.02). Weaning ages ranged from 2.7-8.0 years, but 66.7% (42 calves) were weaned by their 4th birthday. Females tended to wean mid-pregnancy. Accordingly, median inter-birth interval was 4.1 years. Female reproductive success was classified as 0, 1, 2, or 3 according to the number of calves who survived to age three over a 10 yr. period (N=38 females with complete histories). We examined whether factors affecting predation or food availability, water depth and group size, were related to female reproductive success. Group size was unrelated to water depth or female reproductive success, but reproductive success was predicted by water depth (p<.002). Shallow water may allow mothers and calves to detect and avoid predatory sharks. Alternatively, or additionally, prey density may be higher in shallow water compared to deep water.

1999. Connor RC, Heithaus MR and Barre LM. Superalliance of bottlenose dolphins. Nature. 371: 571-572.

It is quite common to find several levels of nested male alliances in human political organization, but these are extremely rare in other species. Yet we found that male bottlenose dolphins (Tursiops sp.) at Shark Bay, Western Australia, form two levels of alliance within a social network of more than 400 individuals. Fourteen of the males formed highly labile alliances, rather than the more typical stable ones, and joined forces in a large 'superalliance' that competed directly with smaller teams of stable alliances.

1999. Mann J and Barnett H. Lethal tiger shark (Galeocerdo cuvieri) attack on bottlenose dolphin (Tursiops sp.) calf: Defense and reactions by the mother. Marine Mammal Science. 15(2): 568-575.

Tiger sharks ( Galeocerdo cuvier) are known to prey on bottlenose dolphins (Tursiops sp.) (Bass et al. 1975, Corkeron et al. 1987, Cockroft et al. 1989, Simpfendorfer 1992), but no attacks have been directly observed. The few observed shark attacks on delphinids involved mostly injured or dead individuals (e.g., Wood et al. 1970, ross and Bass 1971, Leatherwood et al. 1972). We document here an unusual event involving a lethal attack by a tiger shark on a bottlenose dolphin calf and subsequent defense of the calf carcass by the mother. The mother-calf pair was part of a longitudinal study; thus we present systematic observational data on maternal behavior and associates in the weeks before and following the attack.

1999. Mann J and Smuts BB. Behavioral development in wild bottlenose dolphin newborns. Behaviour. 136: 529-566.

Newborn characteristics, patterns of motoric and social behavioural development, and mother-infant relationships in free-ranging and semi-provisioned bottlenose dolphins (Tursiops sp.) are examined. Nine newborns were observed for 189 hours over the first 10 weeks of life. Newborn infants breathe more often than their mothers, and synchronize their breathing and swimming with her soon after birth, but show a gradual decline in synchrony as they age. Virtually all patterns of infant behaviour, mother-infant proximity, and spatial relationships with the mother changed as a function of infant age. Maternal activity, however, did not change over time, except that mothers decreased their role in maintaining proximity to their infants from the first month to the second month of infant life. Infants spent less time close to their mothers, less time echelon swimming (close, alongside the mother), and more time infant-position swimming (in contact under the mother) as they aged. Infants spent more time traveling and socializing independently over time. They also separated from their mothers more often and for longer periods of time. Infants do not hunt during the newborn period, but are observed "practice hunting" by the end of the first month. Rubbing, petting, chasing, and displaying with other animals (including the mother) were common forms of socializing. Infants frequently initiated rubbing with their mothers, with particular focus on her head region. Infants typically associated with young females, adult females and other infants, but not with adult or subadult males. Developmental shifts and overall patterns are discussed in the context of the bottlenose dolphin's fission-fusion social organization and ecology. The effects of provisioning on dolphin behaviour are addressed.

1999. Smolker RA and Pepper J. Whistle convergence among allied male bottlenose dolphins (Delphinidae, Tursiops sp.) . Ethology. 105(7): 595-617.

Dolphins are adept at learning new vocalizations (whistles) throughout life, an ability thus far demonstrated in few nonhuman mammals. In dolphins, this ability is well documented in captivity but poorly studied in the wild, and little is known of its role in natural social behavior. This study documents the previously unknown phenomenon of whistle convergence among habituated free-living male bottlenose dolphins (Tursiops sp.). Over a 4yr study period, three male subjects formed an alliance, spending most of their time together and cooperating to herd females. Within individuals, whistle repertoires were more variable than expected based on previous studies, mostly performed with captive dolphins, but became less so during the course of the study. Among individuals, the distinctiveness of individual repertoires decreased such that the three males were virtually indistinguishable by the end of the study. Initially, some whistle types were shared. By the end of the study, the three males had formed a close alliance, and had all converged on one particular shared whistle form which they had rarely produced before forming the alliance. The results are discussed in terms of their implications for the prevailing `signature whistle' hypothesis, as well as possible mechanisms and functional significance of whistle convergence among cooperating males.

1998. Mann J and Smuts BB. Natal attraction: Allomaternal care and mother-infant separations in wild bottlenose dolphins. Animal Behaviour. 55: 1097-1113.

To determine whether allomaternal care occurs among bottlenose dolphins, we examined patterns of association and mother-infant separations for eight infants (164.4 focal h) during the first 3 months of life. During the first week of life, three inexperienced females (nullipara and mothers of infants that did not survive the newborn period) attempted to take infants from their mothers 13 times. Mothers responded by rapidly retrieving the infant and threatening the female. By the second week, mothers consistently allowed the same females to escort their infants to tens of metres away from them, suggesting that such separations were no longer risky, possibly because infants had imprinted on their mothers. To determine whether escorts benefited mothers after the first week, we compared maternal behavior when infants were away from their mothers, but alone (solitary separations), to when infants were away, but with escorts (social separations). Mothers were less likely to forage and were more likely to engage in non-foraging activities (socialize, rest or travel) when infants were with young escorts (other dependent infants) compared with when infants were alone. When infants were with older (juvenile or adult) escorts, maternal activity did not differ significantly compared with when infants were alone. This result suggests that escorts did not benefit mothers by allowing them to forage. Inexperienced females that never raised an infant were more likely to escort newborns than were parous experienced females, supporting the 'learning to parent' hypothesis.

1997. Mann J. Individual differences in bottlenose dolphin infants. Family Systems. 4: 35-49.

This paper explores some characteristics that are shared by dolphins and primates and distinguish them, with particular emphasis on the development of individual differences. Some preliminary data on the development of wild bottlenose dolphins are presented. These data illustrate the stability of mother-infant contact over time, a striking contrast to the patterns found in most mammals, and the individual variability of exploratory behavior (time away from mother). The latter is consistent with the inhibited- disinhibited, bold-shy, or restrictive vs. laissez-faire differences found in many species of primates, including humans. These patterns are discussed in relation to the dolphin's social ecology and life history.

1997. Smolker RA, Richards AF, Connor RC, Mann J and Berggren P. Sponge-carrying by Indian Ocean bottlenose dolphins: Possible tool-use by a delphinid Ethology. 103: 454-465.

During long-term research on bottlenose dolphins (Tursiops sp.) in Shark Bay, Western Australia, several individuals were observed carrying sponges, Echinodictyum mesenterinum, on their rostra. Over multiple years, five regularly sighted individuals were usually carrying sponges when encountered (67-100% of encounters). Four additional regularly sighted individuals were observed with sponges just one time each. All five individuals that routinely carried sponges were female. Two of the anomalous, one-time carriers were female, one was likely female, and one was male. Most observations of sponge carrying occurred within a restricted area, a relatively deep water channel (8-10m deep). Surface observations of sponge carrying, including focal animal observations, revealed a stereotyped surfacing and diving pattern, and occasional indications of prey consumption. Three hypotheses are considered regarding the function of sponge carrying: 1. dolphins were playing with the sponges; 2. the sponges contain some compound of use to the dolphins (e.g. for medicinal purposes); and 3. the sponges were used as a tool to aid in foraging. The foraging tool hypothesis is best supported, but the exact manner in which sponges are used remains to be discovered. Sponge carrying is a behavioral specialization, probably involving foraging, and regularly engaged in by only a small proportion of female dolphins in Shark Bay.

1996. Connor RC and Heithaus MR. Approach by great white shark elicits flight response in bottlenose dolphins. Marine Mammal Science. 12: 602-606.

Sharks have been identified as important predators on bottlenose dolphins in several locations, but no actual attacks have been observed and reports of interactions between bottlenose dolphins and sharks are few. Here we report a strong avoidance reaction by a group of nine bottlenose dolphins (Tursiops sp.) to an approach by a 2.5-3m great white shark (Carcharodon carcharias) in Shark Bay, Western Australia. Bottlenose dolphins in Shark Bay are among the smallest known; adult females measured have ranged from 186-207cm and one adult male was measured at around 210cm (unpublished data, Smolker et al. 1992). Thus, at 2.5-3.0m, the shark was longer than the dolphins it encountered.

1996. Connor RC and Smolker RA. 'Pop' goes the dolphin: a vocalization male bottlenose dolphins produce during consortships. Behaviour. 133: 643-662.

Studies of dolphin communication have been hindered by the difficulty of localizing sounds underwater and thus identifying vocalizing individuals. Male bottlenose dolphins (Tursiops sp.; speckled form) in Shark Bay, Western Australia produce a vocalization we call 'pops'. Pops are narrow-band, low frequency pulses with peak energy between 300 and 3000 Hz and are typically produced in trains of 3-30 pops at rates of 6-12 pops/s. Observations on the pop vocalization and associated behavior were made as part of a long-term study of bottlenose dolphins in Shark Bay. During 1987-88 seven dolphins, including three males, frequented a shallow water area where they were daily provisioned with fish by tourists and fishermen. The three males often produced pops when accompanied by single females.

1996. Connor RC, Richards AF, Smolker RA and Mann J. Patterns of female attractiveness in Indian Ocean bottlenose dolphins. Behaviour 133: 37-69.

Hormonal profiles of captive individuals show that bottlenose dolphins (Tursiops sp.) are seasonally polyoestrous, but little is known of reproductive behaviour among free ranging bottlenose dolphins. In Shark Bay, western Australia we have documented for the first time patterns of female attractiveness that may correspond to multiple oestrous cycles. Male bottlenose dolphins in stable alliances of 2-3 individuals form temporary consortships with individual females. Consortships often are established and maintained by aggressive herding. Consortships are associated with reproduction and are a useful measure of a female's attractiveness. Following reproduction, females may become attractive to males when their surviving calf is about 2-2.5 years old or within 1-2 weeks of losing an infant. Individual females are attractive to males for variable periods extending over a number of months, both within and outside of the main breeding season. The duration of attractive periods is greater during breeding season months than during the preceding months. Males sometimes are attracted to females for periods exceeding the reported duration of rising estrogen levels during the follicular stage of the oestrus cycle. Males occasionally have consorted or otherwise been attracted to females in several unusual contexts, including late pregnancy, the first two weeks after parturition, and the day after the loss of a nursing infant. Individual females were consorted by up to 13 males during the season they conceived, supporting predictions of a promiscuous mating system in bottlenose dolphin. Thus, consorting is a strategy by males to monopolize females, but not a completely successful one. Multiple cycling by female bottlenose dolphins may be a strategy to avoid being monopolized by particular males. Given the duration and agonistic nature of many consortships, the benefits to females of such a costly strategy are not obvious. Multiple cycling may reduce the risk of infantcide by males or allow females to mate with preferred males after being monopolized by less desirable males.

1995. Connor RC and Smolker RA. Seasonal changes in the stability of male-male bonds in Indian Ocean Bottlenose dolphins. Aquatic mammals. 21: 213-216.

1995. Mann J, Smolker RA and Smuts BB. Responses to calf entanglement in free-ranging bottlenose dolphins. Marine Mammal Science. 11(1): 168-175.

Entanglement in fishing gear poses severe risks to dolphins and is of enormous ecological concern (Brownell et al. 1989, Perrin et al. in press). Monofilament line does not degrade quickly in water and can cause severe injury or death to numerous forms of marine life. Little is known about the responses of dolphin mothers to injured or entangled calves. Here we describe the behavior of a free-ranging dolphin mother and infant before and after the infant became entangled in fishing line.

1993. Smolker RA, Mann J and Smuts BB. The use of signature whistles during separations and reunions among wild bottlenose dolphin mothers and calves. Behavioral Ecology and Sociobiology. 33: 393-402.

We examine the contexts and patterns of "signature" whistle production by wild bottlenose dolphin mother-infant pairs (Tursiops sp.) 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 infants 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.

1992a. Connor RC, Smolker RA and Richards AF. Two levels of alliance formation among bottlenose dolphins (Tursiops) sp. Proc. Nat. Acad. Sci. 89: 987-990.

In Shark Bay, Western Australia, male bottlenose dolphins (Tursiops sp.) cooperate in pairs and triplets to sequester and control the movements of females. We refer to this behavior as "herding" and to the male pairs and triplets as alliances. During a 25-month study (1987-1989) on the social relationships of males, we documented herding in 10 alliances. Males preferentially herded nonpregnant females likely to be in estrus. Alliance members associated with one another consistently when not herding females. Each alliance associated preferentially with one or two other alliances. Occasionally, two alliances combined and took females from another alliance or defended females against such efforts. This study documents multiple- level alliances within a social group outside of humans.

1992b. Connor RC, Smolker RA and Richards AF. Dolphin alliances and coalitions. In: Harcourt AH and de Waal FBM, (eds), Coalitions and alliances in humans and other animals. Oxford University Press: 415-443.

Recently, much attention has focused on a role for complex social interactions, including alliance formation, in the function and evolution of large brains and intelligence in primates (e.g. Jolly 1966; Humphrey 1976; Kummer 1982; Cheney et al. 1986; Alexander 1989; papers in Byrne and Whiten 1988). Based largely on captive studies, Herman (1980) and Connor and Norris (1982), suggested a link between complex social interactions and the large dolphin brain. Until recently, our knowledge of the social lives of free-ranging dolphins was scant. Now, however, long term studies of several dolphin species are revealing highly complex societies. Here we review: (1) our study of alliances and coalitions among male bottlenose dolphins in Shark Bay, W. Australia; (2) the limited data on coalitions among female dolphins at Shark Bay; (3) evidence for alliances in other populations and species. We then compare alliance formation among male dolphins with alliances and coalitions among male and female primates, including humans.

1992. Smolker RA, Richards AF, Connor RC and Pepper JW. Sex differences in patterns of association among Indian Ocean bottlenose dolphins. Behaviour 123: 38-69.

Patterns of association among bottlenose dolphins resident in Shark Bay, Western Australia were analyzed using party membership data. Parties contained an average of 4.8 individuals, but party size and composition were unstable. While these temporary parties often contained both males and females, long term consistent associations generally were between members of the same sex. The highest association coefficients, resulting from very frequent co-occurrence within parties were between males and between mothers and offspring. Males formed subgroups of two or three individuals who consistently associated with each other, and these were stable over periods of at least seven years in some cases. Male subgroups preferentially associated with particular other male subgroups. Females associated most consistently with other females, although not to the same extent as some males. Female associations were better described as a network rather than discrete subgroups. Male-female associations were generally inconsistent and depended in part on female reproductive state. Mothers and their offspring associated very consistently for at least 4 years.

1990. Connor RC and Smolker RA. Quantitative description of a rare behavioral event: a bottlenose dolphins behavior toward her deceased offspringIn: Leatherwood S and Reeves RR (eds), The Bottlenose Dolphin . New York Academic Press: 355-360.

Opportunities to observe the behaviors of dolphins toward their dead offspring are rare in nature, and existing reports are largely anecdotal (e.g. Hubbs, 1953; Moore, 1953, 1955; Norris and Prescott, 1961). Here we describe the behaviour of a female bottlenose dolphin (Tursiops sp.) during the last hours in which she was sighted in the vicinity of her dead offspring.

1988. Smolker R and Richards AF.Loud sounds during feeding in Indian ocean bottlenose dolphins. In: Nachtigall P and Moore PWB (eds), Animal Sonar: processes and performance Plenum Press, New York: 703-706.

1985. Connor RC and Smolker RA.Habituated dolphins (Tursiops sp.) in Western Australia. Journal of Mammalogy. 66: 398-400.

On the east side of Point Peron, which bisects Shark Bay (25 47'S, 113 43'E) in Western Australia, a small number of bottlenose dolphins (Tursiops sp.) from a local population are habituated to accepting fish-handouts and occasional physical contact from people. According to local residents and regular visitors, such dolphins have been coming to the same area for at least 20 years. Based on our study of this situation from August to October, 1982, we report herein on some previously undescribed behavior in dolphins.

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