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.

Inshore and offshore bottlenose dolphin (Tursiops truncatus) communities distinguished by association patterns near Grand Bahama Island, Bahamas

1999 ◽  
Vol 77 (4) ◽  
pp. 581-592 ◽  
Author(s):  
Kelly A Rossbach ◽  
Denise L Herzing
Keyword(s):  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Site Fidelity ◽  
Bottlenose Dolphins ◽  
Social Groups ◽  
Foraging Strategies ◽  
Association Patterns ◽  
Simple Ratio ◽  
Water Depths

Little is known about the behavior of offshore dolphin populations. Our purpose was to distinguish and describe stable social groups of bottlenose dolphins (Tursiops truncatus) between inshore and offshore West End, Grand Bahama Island (26°42'N, 79°00'W). Photoidentification was conducted from May to September, 1994 to 1996. A simple ratio index described association patterns between dolphins. Multidimensional scaling of association indices (n = 1711 dolphin pairs) distinguished two dolphin communities consisting of 28 dolphins (19 of known sex) found inshore and 15 dolphins (12 of known sex) found greater than or equal to 27 km offshore. Eight of the 15 offshore dolphins were opportunistically photographed in the same region between 1986 and 1990. The two communities were found at different water depths (Mann-Whitney U test, p < 0.01), over distinct bottom types (Kruskal-Wallis test, p < 0.01), and used different bottom-foraging strategies. Long-term site fidelity of up to 10 years and repeated dolphin associations of up to 8 years occurred greater than or equal to 27 km from shore. Dolphins sighted greater than or equal to 15 times averaged 48 associates (SD = 11, n = 28). A dolphin's closest associate was of the same gender 74% of the time. This study is the first to report long-term site fidelity and association patterns of bottlenose dolphins found far from shore.

scholarly journals Robust design capture-recapture analysis of abundance and demographic parameters of Indian River Lagoon common bottlenose dolphins (Tursiops truncatus truncatus)

2020 ◽  
Author(s):  
Wendy Noke Durden ◽  
Eric D. Stolen ◽  
Lydia Moreland ◽  
Elisabeth Howells ◽  
Teresa Jablonski ◽  
...  
Keyword(s):  
Robust Design ◽  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Indian River Lagoon ◽  
Adult Survival ◽  
Demographic Parameters ◽  
Estuarine System ◽  
Mark Recapture ◽  
Temporary Emigration ◽  
Indian River

AbstractAccurate estimates of abundance are critical to species management and conservation. Common bottlenose dolphins (Tursiops truncatus truncatus) inhabiting the Indian River Lagoon (IRL) estuarine system along the east coast of Florida are impacted by anthropogenic activities and have had multiple unexplained mortality events, necessitating precise estimates of demographic and abundance parameters to implement management strategies. Mark-recapture methodology following a Robust Design survey was used to estimate abundance, adult survival, and temporary emigration for the IRL estuarine system stock of bottlenose dolphins. Models included a parameter (time since first capture) to assess evidence for transient individuals. Boat-based photo-identification surveys (n = 135) were conducted along predetermined contour and transect lines throughout the entire IRL (2016-2017). The best fitting model included the “transient” parameter to survival, allowed survival to vary by primary period, detection to vary by secondary session, and did not allow temporary emigration. Dolphin abundance ranged from 981 (95% CI: 882-1,090) in winter to 1,078 (95% CI: 968-1,201) in summer with a mean of 1,032 (95% CI: 969 -1,098). Model averaged seasonal survival rate for marked residents ranged from 0.85-1.00. Capture probability ranged from 0.20 to 0.42 during secondary sessions and transient rate from 0.06 to 0.07. This study represents the first Robust design mark-recapture survey effort to estimate abundance for IRL dolphins and provides parameter estimates to optimize sampling design of future studies. Transients included individuals with home ranges extending north of the IRL requiring further assessment of stock delineation. Results were remarkably similar to prior abundance estimates resulting from line-transect aerial surveys and were consistent with a stable population. Data will enable managers to evaluate the impact of fisheries-related takes as well as enable future comparisons of demographic parameters for a dolphin population that continues to sustain large scale mortality events and anthropogenic impacts.

Small-Scale Movement Patterns, Activity Budgets, and Association Patterns of Radio-Tagged Indian River Lagoon Bottlenose Dolphins (Tursiops truncatus)

2019 ◽  
Vol 45 (1) ◽  
pp. 66-87 ◽  
Author(s):  
Wendy Noke Durden ◽  
Greg O’Corry-Crowe ◽  
Steve Shippee ◽  
Teresa Jablonski ◽  
Sarah Rodgers ◽  
...  
Keyword(s):  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Indian River Lagoon ◽  
Movement Patterns ◽  
Small Scale ◽  
Association Patterns ◽  
Activity Budgets ◽  
Indian River

Use of photo-identification data to quantify mother–calf association patterns in bottlenose dolphins

2003 ◽  
Vol 81 (8) ◽  
pp. 1421-1427 ◽  
Author(s):  
Kate Grellier ◽  
Philip S Hammond ◽  
Ben Wilson ◽  
Carol A Sanders-Reed ◽  
Paul M Thompson
Keyword(s):  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Small Population ◽  
Association Patterns ◽  
Photo Identification ◽  
Dolphin Population ◽  
The Mean ◽  
First Time

For social mammals living in fission–fusion societies, the mother–infant bond is long and extends beyond the nursing period. We successfully developed a technique, using photo-identification data, to quantify mother–calf association patterns in a small population of bottlenose dolphins, Tursiops truncatus, off eastern Scotland. By statistically comparing association indices between young calves and their associates we assigned 17 individual adults as mothers to 20 young calves with a 5% level of probability. The mean index of association between calves and mothers remained high until at least year 8 of life. While calves were still found in the same schools as their mother, they surfaced beside her less often as their age increased. This is the first time that the mother–calf bond has been quantitatively assessed for any bottlenose dolphin population inhabiting temperate waters. Results are compared with those from subtropical populations and are discussed with respect to the viability of this population.

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

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.

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