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.

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.

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 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.

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

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.

scholarly journals Pregnancy and Fetal Development: Cephalic Presentation and Other Descriptive Ultrasonographic Findings from Clinically Healthy Bottlenose Dolphins (Tursiops truncatus) under Human Care

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 908
Author(s):  
Pietro Saviano ◽  
Letizia Fiorucci ◽  
Francesco Grande ◽  
Roberto Macrelli ◽  
Alessandro Troisi ◽  
...  
Keyword(s):  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Invasive Technique ◽  
Medical Procedures ◽  
Non Invasive ◽  
Dolphin Population ◽  
Human Care ◽  
First Time

Ultrasonography is widely used in veterinary medicine for the diagnosis of pregnancy, and can also be used to monitor abnormal pregnancies, embryonic resorption, or fetal abortion. Ultrasonography plays an important role in modern-day cetacean preventative medicine because it is a non-invasive technique, it is safe for both patient and operator, and it can be performed routinely using trained responses that enable medical procedures. Reproductive success is an important aspect of dolphin population health, as it is an indicator of the future trajectory of the population. The aim of this study is to provide additional relevant data on feto-maternal ultrasonographic monitoring in bottlenose dolphin (Tursiops truncatus) species, for both the clinicians and for in situ population studies. From 2009 to 2019, serial ultrasonographic exams of 11 healthy bottlenose dolphin females kept under human care were evaluated over the course of 16 pregnancies. A total of 192 ultrasound exams were included in the study. For the first time, the sonographic findings of the bottlenose dolphin organogenesis and their correlation with the stage of pregnancy are described. Furthermore, this is the first report that forecasts the cephalic presentation of the calf at birth, according to its position within the uterus.

scholarly journals Female reproductive success and calf survival in a North Sea coastal bottlenose dolphin (Tursiops truncatus) population

PLoS ONE ◽  
2017 ◽  
Vol 12 (9) ◽  
pp. e0185000 ◽  
Author(s):  
Kevin P. Robinson ◽  
Texa M. C. Sim ◽  
Ross M. Culloch ◽  
Thomas S. Bean ◽  
Isabel Cordoba Aguilar ◽  
...  
Keyword(s):  
Reproductive Success ◽  
North Sea ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Female Reproductive Success ◽  
Calf Survival

Bottlenose dolphins in the Netherlands come from two sides: across the North Sea and through the English Channel

2021 ◽  
pp. 1-7
Author(s):  
Jeroen P. A. Hoekendijk ◽  
Mardik F. Leopold ◽  
Barbara J. Cheney
Keyword(s):  
The Netherlands ◽  
North Sea ◽  
Bottlenose Dolphins ◽  
Photo Identification ◽  
The North ◽  
Video Recordings ◽  
Moray Firth ◽  
The North Sea ◽  
The Uk ◽  
Two Sides

Abstract On 19 July 2019 an estimated 20 bottlenose dolphins (Tursiops truncatus) were observed in the Marsdiep, a tidal inlet connecting the North Sea and the Dutch Wadden Sea, between Den Helder and the island of Texel. Photographs and video recordings were made and nine individuals were matched with known dolphins from the Moray Firth, NE Scotland. These are the first matches of this east coast of Scotland population outside the UK and Ireland. Subsequent observations of individuals from this group show that at least some of the animals have returned to Scottish waters, while others were photographed in Danish waters. Furthermore, we report on a photo identification match of a solitary bottlenose dolphin between France and the Netherlands. These matches suggest that bottlenose dolphins, in the Netherlands, originate from two different genetically distinct populations: ‘Coastal South’ and ‘Coastal North’. This evidence of previously unknown long-range movements may have important implications for the conservation and management of this species in European waters.

scholarly journals Ultrasonographic findings associated with normal pregnancy and fetal well‐being in the bottlenose dolphin ( Tursiops truncatus )

2020 ◽  
Vol 61 (2) ◽  
pp. 215-226
Author(s):  
Marina Ivančić ◽  
Forrest M. Gomez ◽  
Whitney B. Musser ◽  
Ashley Barratclough ◽  
Jennifer M. Meegan ◽  
...  
Keyword(s):  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Well Being ◽  
Normal Pregnancy
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