scholarly journals The importance of delineating networks by activity type in bottlenose dolphins ( Tursiops truncatus ) in Cedar Key, Florida

2015 ◽  
Vol 2 (3) ◽  
pp. 140263 ◽  
Author(s):  
Stefanie Gazda ◽  
Swami Iyer ◽  
Timothy Killingback ◽  
Richard Connor ◽  
Solange Brault
Keyword(s):  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Spatial Association ◽  
Population Level ◽  
Activity Type ◽  
Behavioural State ◽  
Activity Networks ◽  
Behavioural Patterns ◽  
The Social ◽  
Large Groups

Network analysis has proved to be a valuable tool for studying the behavioural patterns of complex social animals. Often such studies either do not distinguish between different behavioural states of the organisms or simply focus attention on a single behavioural state to the exclusion of all others. In either of these approaches it is impossible to ascertain how the behavioural patterns of individuals depend on the type of activity they are engaged in. Here we report on a network-based analysis of the behavioural associations in a population of bottlenose dolphins ( Tursiops truncatus ) in Cedar Key, Florida. We consider three distinct behavioural states—socializing, travelling and foraging—and analyse the association networks corresponding to each activity. Moreover, in constructing the different activity networks we do not simply record a spatial association between two individuals as being either present or absent, but rather quantify the degree of any association, thus allowing us to construct weighted networks describing each activity. The results of these weighted activity networks indicate that networks can reveal detailed patterns of bottlenose dolphins at the population level; dolphins socialize in large groups with preferential associations; travel in small groups with preferential associates; and spread out to forage in very small, weakly connected groups. There is some overlap in the socialize and travel networks but little overlap between the forage and other networks. This indicates that the social bonds maintained in other activities are less important as they forage on dispersed, solitary prey. The overall network, not sorted by activity, does not accurately represent any of these patterns.

Resighting and association patterns of bottlenose dolphins (Tursiops truncatus) in the Cedar Keys, Florida: insights into social organization

2001 ◽  
Vol 79 (3) ◽  
pp. 447-456 ◽  
Author(s):  
Ester Quintana-Rizzo ◽  
Randall S Wells
Keyword(s):  
Social Organization ◽  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Aquatic Systems ◽  
Estuarine System ◽  
Association Patterns ◽  
Selective Pressures ◽  
The Social ◽  
Estuarine Systems ◽  
Common Dolphins

Little is known about the social organization of bottlenose dolphins (Tursiops truncatus) inhabiting open estuarine systems. Our purpose was to identify and quantify the resightings of bottlenose dolphins and associations formed among them to provide insights into the social organization of the species in the open estuarine system of the Cedar Keys, Florida. We conducted monthly photographic-identification surveys from June 1996 through May 1997. We identified a total of 233 dolphins of which 217 (93%) were classified into one of four categories based on the number of months in which they were sighted. "Rare" dolphins (sighted during 1–2 months) constituted more than half of these individuals (61%), followed by "occasional" (3–5 months; 20%), "common" (>8 months; 12%), and "frequent" (5–6 months; 7%) dolphins. We quantified the associations for dolphins sighted 10 times (26 common, 12 frequent, and 8 occasional) and found that individuals with different resighting patterns associate with each other but the association is mostly at a low level. The level of association among common dolphins, however, was higher within than between the sexes. Association patterns of common dolphins in the Cedar Keys resemble the associations of resident bottlenose dolphins inhabiting closed estuarine bays, suggesting that the selective pressures which induce such associations are the same in these aquatic systems.

THE SOCIAL STRUCTURE OF BOTTLENOSE DOLPHINS, TURSIOPS TRUNCATUS, IN THE BAHAMAS

2004 ◽  
Vol 20 (4) ◽  
pp. 688-708 ◽  
Author(s):  
Cindy A. Rogers ◽  
Barbara J. Brunnick ◽  
Denise L. Herzing ◽  
John D. Baldwin
Keyword(s):  
Social Structure ◽  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
The Bahamas ◽  
The Social

Diet of the bottlenose dolphin (Tursiops truncatus) in the western Mediterranean Sea

2001 ◽  
Vol 81 (6) ◽  
pp. 1053-1058 ◽  
Author(s):  
C. Blanco ◽  
O. Salomón ◽  
J.A. Raga
Keyword(s):  
Tursiops Truncatus ◽  
Diet Composition ◽  
Bottlenose Dolphins ◽  
Stomach Contents ◽  
Western Mediterranean ◽  
Mediterranean Coast ◽  
Important Prey ◽  
Western Mediterranean Sea ◽  
Causative Factors ◽  
Behavioural Patterns

The stomach contents of 16 bottlenose dolphins Tursiops truncatus (Cetacea: Odontoceti) stranded in the Spanish Mediterranean coast were examined. Remains and size of prey were analysed and correlated with the ecological characteristics and behavioural patterns of this dolphin. Fish and cephalopods represented the main diet components, and hake Merluccius merluccius was the most important prey. The food habits were considered as mainly demersal according to the characteristics of the prey. The study suggested ontogenic and sexual differences in feeding behaviour based on diet composition and hake size. The potential causative factors, particularly as they relate to dolphin social structure, are discussed.

scholarly journals Behaviourally specific preferred associations in bottlenose dolphins, Tursiops spp.

2005 ◽  
Vol 83 (12) ◽  
pp. 1566-1573 ◽  
Author(s):  
S Gero ◽  
L Bejder ◽  
H Whitehead ◽  
J Mann ◽  
R C Connor
Keyword(s):  
Social Relationships ◽  
Bottlenose Dolphins ◽  
Adult Males ◽  
Short Term ◽  
Shark Bay ◽  
Behavioural State ◽  
The Social ◽  
Association Group ◽  
Males And Females ◽  
Free Ranging

We investigated association patterns of 52 photographically identified, free-ranging bottlenose dolphins (Tursiops spp. Gervais, 1855) across four behavioural states (rest, travel, social, and foraging/feeding) to investigate how behavioural state influences patterns of association. Group composition and behavioural data were extracted from 2178 encounter surveys collected over 3 years. Analyses revealed three general types of association: (1) affiliates, which consistently demonstrate preferred associations across all behavioural states; (2) acquaintances, which never form preferred associations but still associate in at least one behavioural state; and (3) behavioural associates, which form preferred associations in at least one, but not all behavioural states. The majority of associations in Shark Bay, Australia, are acquaintance type (38.2%), with affiliates (5.7%, principally between adult males) and behavioural associates (28.9%, principally between juveniles) being relatively rarer. Permutation tests identified behaviourally specific preferred associations during all behavioural states. Although behaviourally specific preferred associations appear to exist within the Shark Bay social structure, it seems that the social organization and mating system constrain the social relationships for the majority of males and females in differing ways which prevent them from having behavioural associates, leaving juveniles free to associate based on short-term expediency and behavioural specific needs.

scholarly journals The Development of Echolocation in Bottlenose Dolphins (Tursiops truncatus)

2016 ◽  
Vol 29 ◽  
Author(s):  
Jennifer H. Harder ◽  
Heather M. Hill ◽  
Kathleen M. Dudzinski ◽  
Karissa T. Sanabria ◽  
Sara Guarino ◽  
...  
Keyword(s):  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Future Research ◽  
Anatomy And Physiology ◽  
Behavioral Observations ◽  
Sonar System ◽  
Social Grouping ◽  
The Social ◽  
Click Train

This study aimed to expand on previous efforts to evaluate the ontogeny of echolocation in Atlantic bottlenose dolphins (Tursiops truncatus). Data consisted of echolocation recordings and concurrent behavioral observations taken from one calf in 2000 and from five additional dolphin calves and their mothers in 2002 housed at the U.S. Naval facility in San Diego, CA. A total of 361 echolocation click train samples from calves were recorded weekly over the first 6 months of the calves’ lives. The earliest calf echolocation train was recorded at 22 days postpartum and the number of echolocation attempts from calves increased steadily with age. Calf echolocation trains increased in duration and the number of clicks per train with age while train density (clicks/sec) and interclick interval values remained more consistent. Calves swimming independent of their mothers produced more click trains, especially when multiple calves were present in the social grouping. When considering these results in the context of possible maturation of a calf’s melon physiology, it seems very likely that the first two months of life are critical for the development of echolocation and related behaviors. While the first click train recorded in this sample was approximately 3 weeks of age by two different calves, it is possible that dolphin calves may innately produce functional sonar clicks immediately after birth, which were not captured in the current study. Future research will need to investigate this possibility using more controlled conditions and a better understanding of the anatomy and physiology of the sonar system of neonates as well as the possible role of the mother in echolocation development.

scholarly journals The social structure of Golfo Dulce bottlenose dolphins ( Tursiops truncatus ) and the influence of behavioural state

2016 ◽  
Vol 3 (8) ◽  
pp. 160010 ◽  
Author(s):  
Kelsey Moreno ◽  
Alejandro Acevedo-Gutiérrez
Keyword(s):  
Social Structure ◽  
Bottlenose Dolphins ◽  
Ecological Factors ◽  
Mating Strategies ◽  
Behavioural Plasticity ◽  
Social Strategies ◽  
Behavioural State ◽  
The Social ◽  
Well Differentiated ◽  
Highly Correlated

Ecological factors such as habitat and food availability affect the social structure of bottlenose dolphins ( Tursiops spp.). Here, we describe the social structure of bottlenose dolphins ( T. truncatus ) in Golfo Dulce, Costa Rica, a semi-enclosed, fjord-like tropical embayment resembling a pelagic system. We also examine behaviour-linked social strategies by comparing social structure relative to behavioural state: feeding versus non-feeding. We analysed 333 sightings over 210 days from boat-based surveys. Despite the uniqueness of the area, the 47 analysed adults had a social structure similar to other populations: a well-differentiated fission–fusion society with sex-specific patterns of associations and aggression. These results indicate that differences in social structure relative to other populations were a matter of degree. Association strength of dyads was highly correlated across behavioural states, indicating constraints on social fluidity. Males displayed a marked difference in lagged association rate and females displayed a small difference in association homogeneity between states. We suggest this difference in population-wide social connections between behavioural states, particularly for males, was due to mating strategies, a pressure which is strongest during non-feeding behaviour and relaxed during feeding. This finding highlights the importance of considering behavioural state when examining individual bonds and the behavioural plasticity for which the bottlenose dolphin is well known.

scholarly journals Tour boats affect the activity patterns of bottlenose dolphins (Tursiops truncatus) in Bocas del Toro, Panama

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8804 ◽  
Author(s):  
Ayshah Kassamali-Fox ◽  
Fredrik Christiansen ◽  
Laura J. May-Collado ◽  
Eric A. Ramos ◽  
Beth A. Kaplin
Keyword(s):  
Markov Chain ◽  
Tursiops Truncatus ◽  
Transition Probabilities ◽  
Bottlenose Dolphins ◽  
Activity Patterns ◽  
Biological Significance ◽  
Population Level ◽  
Tourism Industry ◽  
Activity Budgets ◽  
Bocas Del Toro

Bottlenose dolphins (Tursiops truncatus) of the Bocas del Toro archipelago are targeted by the largest boat-based cetacean watching operation in Panama. Tourism is concentrated in Dolphin Bay, home to a population of resident dolphins. Previous studies have shown that tour boats elicit short-term changes in dolphin behavior and communication; however, the relationship of these responses to the local population’s biology and ecology is unclear. Studying the effects of tour boats on dolphin activity patterns and behavior can provide information about the biological significance of these responses. Here, we investigated the effects of tour boat activity on bottlenose dolphin activity patterns in Bocas del Toro, Panama over 10 weeks in 2014. Markov chain models were used to assess the effect of tour boats on dolphin behavioral transition probabilities in both control and impact scenarios. Effect of tour boat interactions was quantified by comparing transition probabilities of control and impact chains. Data were also used to construct dolphin activity budgets. Markov chain analysis revealed that in the presence of tour boats, dolphins were less likely to stay socializing and were more likely to begin traveling, and less likely to begin foraging while traveling. Additionally, activity budgets for foraging decreased and traveling increased as an effect of tour boat presence. These behavioral responses are likely to have energetic costs for individuals which may ultimately result in population-level impacts. Boat operator compliance with Panamanian whale watching regulations is urgently needed to minimize potential long-term impacts on this small, genetically distinct population and to ensure the future viability of the local tourism industry.

New research frameworks in the study of chimpanzee and gorilla sociality and communication

2019 ◽  
Author(s):  
Sam G. B. Roberts ◽  
Anna Roberts
Keyword(s):  
Social Evolution ◽  
Social Complexity ◽  
Brain Size ◽  
Social Systems ◽  
Strongly Correlated ◽  
The Social ◽  
Human Social Evolution ◽  
Research Frameworks ◽  
New Research ◽  
Large Groups

Group size in primates is strongly correlated with brain size, but exactly what makes larger groups more ‘socially complex’ than smaller groups is still poorly understood. Chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) are among our closest living relatives and are excellent model species to investigate patterns of sociality and social complexity in primates, and to inform models of human social evolution. The aim of this paper is to propose new research frameworks, particularly the use of social network analysis, to examine how social structure differs in small, medium and large groups of chimpanzees and gorillas, to explore what makes larger groups more socially complex than smaller groups. Given a fission-fusion system is likely to have characterised hominins, a comparison of the social complexity involved in fission-fusion and more stable social systems is likely to provide important new insights into human social evolution

Cranial crassicaudiasis in two coastal dolphin species from South Africa is predominantly a disease of immature individuals

2020 ◽  
Vol 139 ◽  
pp. 93-102 ◽  
Author(s):  
MF Van Bressem ◽  
P Duignan ◽  
JA Raga ◽  
K Van Waerebeek ◽  
N Fraijia-Fernández ◽  
...  
Keyword(s):  
South Africa ◽  
Bone Development ◽  
Bottlenose Dolphins ◽  
Fatal Outcome ◽  
Population Level ◽  
Cape Coast ◽  
Osteolytic Lesions ◽  
Immune Mediated ◽  
Significant Difference ◽  
The Difference

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.

Seasonal Abundance and Site Fidelity of Bottlenose Dolphins (Tursiops truncatus) in Mississippi Sound

2004 ◽  
Vol 30 (2) ◽  
pp. 299-310 ◽  
Author(s):  
Carrie W. Hubard ◽  
Kathy Maze-Foley ◽  
Keith D. Mullin ◽  
William W. Schroeder
Keyword(s):  
Tursiops Truncatus ◽  
Site Fidelity ◽  
Bottlenose Dolphins ◽  
Seasonal Abundance ◽  
Mississippi Sound
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