A preliminary photo‐identification study of bottlenose dolphin(Tursiops truncatus)in Hauraki Gulf, New Zealand

2008 ◽  
Vol 42 (4) ◽  
pp. 465-472 ◽  
Author(s):  
J. Berghan ◽  
K. D. Algie ◽  
K.A. Stockin ◽  
N. Wiseman ◽  
R. Constantine ◽  
...  
Keyword(s):  
New Zealand ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Photo Identification

A time-based method for defining associations using photo-identification

Behaviour ◽  
2017 ◽  
Vol 154 (9-10) ◽  
pp. 1029-1050 ◽  
Author(s):  
D.R. Johnston ◽  
W. Rayment ◽  
E. Slooten ◽  
S.M. Dawson
Keyword(s):  
New Zealand ◽  
Tursiops Truncatus ◽  
Group Membership ◽  
Bottlenose Dolphins ◽  
Digital Photography ◽  
Social Structures ◽  
Data Set ◽  
Association Analyses ◽  
Photo Identification

Photo-identification is an invaluable method for documenting associations. Based on the assumption that individuals photographed close together in time are physically close in space, the metadata associated with digital photography offers an opportunity to base association analyses on time between images. This was tested via analysis of associations within a population of bottlenose dolphins (Tursiops truncatus) in Doubtful Sound, New Zealand. We compared the widely used group-membership method and an alternative time-based method. Overall social structures between methods were similar; high degrees of association among all individuals and little support for sub-groups. Results also indicated an increase in the precision of pairwise indices for the time-based method. This study validated the approach of using time as a basis for analyses of associations. Importantly, this method can be retrospectively applied to any photo-ID data set in which images of uniquely identifiable individuals are time-stamped by the camera.

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.

Using blubber biopsies to provide ecological information about bottlenose dolphins (Tursiops truncatus) around the Azores

2007 ◽  
Vol 87 (1) ◽  
pp. 223-230 ◽  
Author(s):  
M.J. Walton ◽  
M.A. Silva ◽  
S.M. Magalhães ◽  
R. Prieto ◽  
R.S. Santos
Keyword(s):  
Fatty Acid ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Fatty Acid Profiles ◽  
The Bahamas ◽  
Azores Archipelago ◽  
Photo Identification ◽  
Ecological Information ◽  
Island Group

Fatty acid profiles were used to investigate aspects of bottlenose dolphin populations around the Azores archipelago. Biopsy samples were obtained from 70 dolphins during the period 2002–2004. No statistically significant differences in profiles were found between different island groups, between sexes or between year of sampling. Thus no evidence was seen for island group fidelity, in contrast to bottlenose dolphins found around similar island groups such as the Hawaiian archipelago or the Bahamas. The findings are consistent with concurrent genetic and photo-identification studies on dolphins in the Azores.

Presenting vertebral deformities in bottlenose dolphin Tursiops truncatus calves from a protected population in northeast Scotland

2020 ◽  
Vol 140 ◽  
pp. 103-108
Author(s):  
KP Robinson ◽  
GN Haskins ◽  
SM Eisfeld-Pierantonio ◽  
T Sidiropoulos ◽  
CCG Bamford
Keyword(s):  
North Sea ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Maternal Separation ◽  
Well Being ◽  
Early Age ◽  
Photo Identification ◽  
Causative Factors ◽  
Moray Firth ◽  
Dolphin Population

Photographs collected during a 23 yr photo-identification study in the Moray Firth were examined to assess the prevalence, type and severity of vertebral deformations present in bottlenose dolphin Tursiops truncatus calves. Fifteen cases of presenting spinal anomalies (scoliosis, kyphosis, lordosis and combinations thereof) of variable severity were identified in 7.4% of all known calves from the population. Thirteen of the 15 anomalies were either manifest from birth or acquired from an early age, as ascertained from longitudinal sightings histories of their mothers. Most afflicted calves died during early development or shortly after maternal separation. However, 3 survived to adulthood and persist in the population to date, in addition to 2 dependent infants whose fate remains to be established. At 15+ yr of age, the oldest surviving individual was remarkably one of the most severe cases identified, highlighting the ability of these delphinids for adaptation to such gross structural deformities. The aetiology of the observed conditions could be attributed to a range of causative factors that may have implications for the well-being and health of this North Sea coastal dolphin population, a topic which merits further investigation.

Bottlenose Dolphin (Tursiops truncatus) Abundance, Site Fidelity, and Group Dynamics in the Marlborough Sounds, New Zealand

2009 ◽  
Vol 35 (4) ◽  
pp. 511-522 ◽  
Author(s):  
Monika G. Merriman ◽  
Tim M. Markowitz ◽  
April D. Harlin-Cognato ◽  
Karen A. Stockin
Keyword(s):  
New Zealand ◽  
Group Dynamics ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Site Fidelity

scholarly journals Female reproductive output in a Mediterranean bottlenose dolphin Tursiops truncatus population

2020 ◽  
Vol 29 ◽  
pp. 123-136
Author(s):  
MF Blasi ◽  
C Bruno ◽  
L Boitani
Keyword(s):  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Reproductive Output ◽  
Bottlenose Dolphins ◽  
Reproductive Pattern ◽  
Photo Identification ◽  
Conservation Actions ◽  
Dolphin Population ◽  
The Mean ◽  
June July

The reproductive output of wild bottlenose dolphins Tursiops truncatus has extensively been investigated; nevertheless, it remains widely unexplored in the Mediterranean Sea. We investigated the reproductive history of female bottlenose dolphins in the Aeolian Archipelago (Italy). Thirteen years of photo-identification data were used to track the reproductive pattern of 7 females and their 16 calves. The birth period was accurately estimated within 1 mo for 6 calves (37.5%), peaking in June/July. The mean number of calves for females was 2.3 ± 1.1 (SD), ranging from 1 to 4. The mean interbirth interval was 3.5 ± 1.6 yr, ranging from 2 to 7 yr. The mean weaning age was 3.2 ± 0.6 yr, although 1 calf may have been weaned as late as its fifth birthday. Mother-calf postweaning associations were tracked for 9 calves and ranged from 4 to 10 yr of residence in the maternal group of the calf. The age of first pregnancy was 7.5 yr. The number of calves was influenced by the mean maternal group size, with females that were sighted in larger groups having more calves. However, the number of calves was not influenced by the strength of the associations of mothers with other females. Calf mortality by age 1 was high (12.5%). Two juveniles also died postweaning within 6 yr of their birth. Finally, 2 females may have died during the study, as they were not re-sighted at the end of the study. Our results highlight the need to implement urgent conservation actions to protect this bottlenose dolphin population.

scholarly journals Distribution and abundance of bottlenose dolphin (Tursiops truncatus) over the French Mediterranean continental shelf

2019 ◽  
Author(s):  
Hélène Labach ◽  
Caroline Azzinari ◽  
Maxime Barbier ◽  
Cathy Cesarini ◽  
Boris Daniel ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Encounter Rate ◽  
Habitat Directive ◽  
Photo Identification ◽  
Gulf Of Lion ◽  
Capture Recapture ◽  
First Time

AbstractThe Mediterranean bottlenose dolphin (Tursiops truncatus) sub-population is listed as vulnerable by the International Union for Conservation of Nature. This species is strictly protected in France and the designation of Special Areas of Conservation (SAC) is required under the European Habitat Directive. However, little information is available about the structure, dynamic and distribution of the population in the French Mediterranean waters. We collected photo-identification data over the whole French Mediterranean continental shelf all year round between 2013 and 2015. We sighted 151 groups of bottlenose dolphins allowing the individually photo-identification of 1,060 animals. The encounter rate distribution showed the presence of bottlenose dolphins over the whole continental shelf all year round. Using capture-recapture methods, we estimated for the first time the size of the bottlenose dolphin resident population at 557 individuals (95% confidence interval: 216-872) along the French Mediterranean continental coast. Our results were used in support of the designation of a new dedicated SAC in the Gulf of Lion and provide a reference state for the bottlenose dolphin monitoring in the French Mediterranean waters in the context of the Marine Strategy Framework Directive.

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