scholarly journals Individual, unit and vocal clan level identity cues in sperm whale codas

2016 ◽  
Vol 3 (1) ◽  
pp. 150372 ◽  
Author(s):  
Shane Gero ◽  
Hal Whitehead ◽  
Luke Rendell
Keyword(s):  
Social Structure ◽  
Communication Systems ◽  
Social Complexity ◽  
Animal Communication ◽  
Sperm Whale ◽  
Ocean Basin ◽  
Photo Identification ◽  
The Social ◽  
Complexity Hypothesis ◽  
Social Units

The ‘social complexity hypothesis’ suggests that complex social structure is a driver of diversity in animal communication systems. Sperm whales have a hierarchically structured society in which the largest affiliative structures, the vocal clans, are marked on ocean-basin scales by culturally transmitted dialects of acoustic signals known as ‘codas’. We examined variation in coda repertoires among both individual whales and social units—the basic element of sperm whale society—using data from nine Caribbean social units across six years. Codas were assigned to individuals using photo-identification and acoustic size measurement, and we calculated similarity between repertoires using both continuous and categorical methods. We identified 21 coda types. Two of those (‘1+1+3’ and ‘5R 1 ’) made up 65% of the codas recorded, were shared across all units and have dominated repertoires in this population for at least 30 years. Individuals appear to differ in the way they produce ‘5R 1 ’ but not ‘1+1+3’ coda. Units use distinct 4-click coda types which contribute to making unit repertoires distinctive. Our results support the social complexity hypothesis in a marine species as different patterns of variation between coda types suggest divergent functions, perhaps representing selection for identity signals at several levels of social structure.

scholarly journals Tolerant and intolerant macaques show different levels of structural complexity in their vocal communication

2020 ◽  
Vol 287 (1928) ◽  
pp. 20200439
Author(s):  
Nancy Rebout ◽  
Arianna De Marco ◽  
Jean-Christophe Lone ◽  
Andrea Sanna ◽  
Roberto Cozzolino ◽  
...  
Keyword(s):  
Communication Systems ◽  
Social Complexity ◽  
Vocal Communication ◽  
Rhesus Macaques ◽  
Structural Complexity ◽  
Social Environments ◽  
Social Tolerance ◽  
The Social ◽  
Vocal Signals ◽  
Complexity Hypothesis

We tested the social complexity hypothesis which posits that animals living in complex social environments should use complex communication systems. We focused on two components of vocal complexity: diversity (number of categories of calls) and flexibility (degree of gradation between categories of calls). We compared the acoustic structure of vocal signals in groups of macaques belonging to four species with varying levels of uncertainty (i.e. complexity) in social tolerance (the higher the degree of tolerance, the higher the degree of uncertainty): two intolerant species, Japanese and rhesus macaques, and two tolerant species, Tonkean and crested macaques. We recorded the vocalizations emitted by adult females in affiliative, agonistic and neutral contexts. We analysed several acoustic variables: call duration, entropy, time and frequency energy quantiles. The results showed that tolerant macaques displayed higher levels of vocal diversity and flexibility than intolerant macaques in situations with a greater number of options and consequences, i.e. in agonistic and affiliative contexts. We found no significant differences between tolerant and intolerant macaques in the neutral context where individuals are not directly involved in social interaction. This shows that species experiencing more uncertain social interactions displayed greater vocal diversity and flexibility, which supports the social complexity hypothesis.

scholarly journals Genetic relatedness delineates the social structure of southern Australian bottlenose dolphins

2019 ◽  
Vol 30 (4) ◽  
pp. 948-959 ◽  
Author(s):  
Fernando Diaz-Aguirre ◽  
Guido J Parra ◽  
Cecilia Passadore ◽  
Luciana Möller
Keyword(s):  
Social Structure ◽  
Genetic Relatedness ◽  
Social Systems ◽  
Bottlenose Dolphins ◽  
South Australia ◽  
Intrinsic Factors ◽  
Photo Identification ◽  
The Social ◽  
Modularity Analysis ◽  
Network Metrics

AbstractSocial relationships represent an adaptive behavioral strategy that can provide fitness benefits to individuals. Within mammalian societies, delphinids are known to form diverse grouping patterns and show a variety of social systems. However, how ecological and intrinsic factors have shaped the evolution of such diverse societies is still not well understood. In this study, we used photo-identification data and biopsy samples collected between March 2013 and October 2015 in Coffin Bay, a heterogeneous environment in South Australia, to investigate the social structure of southern Australian bottlenose dolphins (Tursiops cf. australis). Based on the data from 657 groups of dolphins, we used generalized affiliation indices, and applied social network and modularity methods to study affiliation patterns among individuals and investigate the potential presence of social communities within the population. In addition, we investigated genetic relatedness and kinship relationships within and between the communities identified. Modularity analysis revealed that the Coffin Bay population is structured into 2 similar sized, mixed-sex communities which differed in ranging patterns, affiliation levels and network metrics. Lagged association rates also indicated that nonrandom affiliations persisted over the study period. The genetic analyses suggested that there was higher relatedness, and a higher proportion of inferred full-sibs and half-sibs, within than between communities. We propose that differences in environmental conditions between the bays and kinship relationships are important factors contributing to the delineation and maintenance of this social structure.

scholarly journals Social complexity as a proximate and ultimate factor in communicative complexity

2012 ◽  
Vol 367 (1597) ◽  
pp. 1785-1801 ◽  
Author(s):  
Todd M. Freeberg ◽  
Robin I. M. Dunbar ◽  
Terry J. Ord
Keyword(s):  
Social Complexity ◽  
Social Systems ◽  
Causal Factor ◽  
Human Language ◽  
The Social ◽  
Alternative Hypotheses ◽  
Group Members ◽  
Complexity Hypothesis ◽  
Complex Social Systems ◽  
Over Time

The ‘social complexity hypothesis’ for communication posits that groups with complex social systems require more complex communicative systems to regulate interactions and relations among group members. Complex social systems, compared with simple social systems, are those in which individuals frequently interact in many different contexts with many different individuals, and often repeatedly interact with many of the same individuals in networks over time. Complex communicative systems, compared with simple communicative systems, are those that contain a large number of structurally and functionally distinct elements or possess a high amount of bits of information. Here, we describe some of the historical arguments that led to the social complexity hypothesis, and review evidence in support of the hypothesis. We discuss social complexity as a driver of communication and possible causal factor in human language origins. Finally, we discuss some of the key current limitations to the social complexity hypothesis—the lack of tests against alternative hypotheses for communicative complexity and evidence corroborating the hypothesis from modalities other than the vocal signalling channel.

scholarly journals The influence of fish farm activity on the social structure of the common bottlenose dolphin in Sardinia (Italy)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10960
Author(s):  
Serena Frau ◽  
Fabio Ronchetti ◽  
Francesco Perretti ◽  
Alberto Addis ◽  
Giulia Ceccherelli ◽  
...  
Keyword(s):  
Social Structure ◽  
Bottlenose Dolphin ◽  
Foraging Strategy ◽  
Important Change ◽  
Fish Farm ◽  
Photo Identification ◽  
Common Bottlenose Dolphin ◽  
The Social ◽  
Dolphin Population ◽  
The Common

In a wide variety of habitats, including some heavily urbanised areas, the adaptability of populations of common bottlenose dolphin (Tursiops truncatus) may depend on the social structure dynamics. Nonetheless, the way in which these adaptations take place is still poorly understood. In the present study we applied photo-identification techniques to investigate the social structure of the common bottlenose dolphin population inhabiting the Gulf of Alghero (Sardinia, Italy), analysing data recorded from 2008 to 2019. The social structure analysis showed a division of the entire population into five different communities and the presence of non-random associations, while there was no evidence of segregation between sexes. Furthermore, results highlighted an important change in social structure through time, likely due to a reduction in fish farm activity since 2015. The division of the population into different communities, the presence of segregation based on the foraging strategy (inside or outside the fish farm area) and the social network measures were evaluated by analysing independently the two datasets: the intense and low farm activity periods: 2008–2014 and 2015–2020, respectively. Segregation among individuals belonging to the same foraging strategy class was found only in the earlier period, and the composition of the four communities was consistent with this result. Our study improves the knowledge about bottlenose dolphin adaptation, as a lower complexity in social structure was linked to a reduction in anthropogenic food availability.

The social organization of sperm whales in the Gulf of California and comparisons with other populations

2009 ◽  
Vol 89 (5) ◽  
pp. 975-983 ◽  
Author(s):  
Nathalie Jaquet ◽  
Diane Gendron
Keyword(s):  
Social Organization ◽  
Gulf Of California ◽  
Ecological Factors ◽  
Sperm Whale ◽  
Galapagos Islands ◽  
Galápagos Islands ◽  
Sperm Whales ◽  
Photo Identification ◽  
Long Term Study ◽  
The Social

Intra-specific variation in social organization provides valuable insights into the selective forces driving social evolution. Sperm whales are distributed globally and live far from shore, thus obtaining large sample sizes on social organization in multiple areas is logistically challenging and few comparative studies exist. In order to address how ecological factors influence sociality, we investigated the social organization of sperm whales in the Gulf of California (GoC) using a long-term study (1998–2004) and compare our results to other published studies. Standard photo-identification and behavioural observation techniques were used. Group size was calculated from photographic mark–recaptures using a Petersen estimator. Social organization was investigated using SocProg 2.3. Mean typical group sizes in the GoC were similar to those in the Galápagos Islands, Chile and Seychelles (24.7, 24.8, 30.4 and 18 individuals respectively), but substantially larger than in the Sargasso Sea, Caribbean and northern Gulf of Mexico (12.0, 6.4 and 6.9 individuals respectively). Sperm whale social organization in the GoC best fitted a constant companion/casual acquaintance model, where permanent units sizes were 12.5 individuals and two units usually associated together to form a group. This structure is similar to the situation in the Galápagos Islands and Chile areas. However, groups were more stable in the GoC than in the South Pacific, as groups stayed together for periods of about 80 days versus about ten days in the Galápagos Islands and Chile. It is likely that differences in the social organization between the study areas in the Pacific and Atlantic Oceans were due to differences in predation pressure and/or food resources. We suggest that, site-specific ecological factors are likely to influence fundamental aspects of sperm whale social organization.

Kinship Ties and Young Patricians in Fifteenth-Century Venice

1985 ◽  
Vol 38 (2) ◽  
pp. 240-270 ◽  
Author(s):  
Stanley Chojnacki
Keyword(s):  
Social Structure ◽  
Fifteenth Century ◽  
Ruling Class ◽  
Late Medieval ◽  
The Social ◽  
The Family ◽  
Long Time ◽  
Renaissance Italy ◽  
Social Units ◽  
Kinship Ties

Regimes and families: historians have recently enriched our understanding of the patrician regimes of late-medieval and Renaissance Italy by analyzing relations among their component social units. This essay will contribute to this literature by throwing some light on the social structure and practices of the ruling class of fifteenth-century Venice. For a long time, but with quickening rhythm in the last decade or so, historians of Venice have been charting various currents that ran through the Venetian patriciate. On the whole, though, they have preferred to concentrate on political and economic groupings, less on the family and kinship patterns that fascinate investigators of other cities, notably Florence.

scholarly journals Does Social Complexity Drive Vocal Complexity? Insights from the Two African Elephant Species

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3071
Author(s):  
Daniela Hedwig ◽  
Joyce Poole ◽  
Petter Granli
Keyword(s):  
Communication Systems ◽  
Social Complexity ◽  
Vocal Communication ◽  
Reproductive Rate ◽  
African Elephant ◽  
African Elephants ◽  
Savanna Elephant ◽  
The Social ◽  
Forest Elephant ◽  
Vocal Complexity

The social complexity hypothesis (SCH) for communication states that the range and frequency of social interactions drive the evolution of complex communication systems. Surprisingly, few studies have empirically tested the SHC for vocal communication systems. Filling this gap is important because a co-evolutionary runaway process between social and vocal complexity may have shaped the most intricate communication system, human language. We here propose the African elephant Loxodonta spec. as an excellent study system to investigate the relationships between social and vocal complexity. We review how the distinct differences in social complexity between the two species of African elephants, the forest elephant L. cyclotis and the savanna elephant L. africana, relate to repertoire size and structure, as well as complex communication skills in the two species, such as call combination or intentional formant modulation including the trunk. Our findings suggest that Loxodonta may contradict the SCH, as well as other factors put forth to explain patterns of vocal complexity across species. We propose that life history traits, a factor that has gained little attention as a driver of vocal complexity, and the extensive parental care associated with a uniquely low and slow reproductive rate, may have led to the emergence of pronounced vocal complexity in the forest elephant despite their less complex social system compared to the savanna elephant. Conclusions must be drawn cautiously, however. A better understanding of vocal complexity in the genus Loxodonta will depend on continuing advancements in remote data collection technologies to overcome the challenges of observing forest elephants in their dense rainforest habitat, as well as the availability of directly comparable data and methods, quantifying both structural and contextual variability in the production of rumbles and other vocalizations in both species of African elephants.

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