The 2015 field season was incredibly successful thanks largely to our amazing crew (Teresa Borcuch and Giulia Donati), without whom this success would not have been possible. In four months, we conducted hundreds of behavioural surveys across our entire study area and collected more than one hundred tissue samples.
We are sad to report that several dolphins, whom we have known for decades, have no longer been sighted in recent times. The most prominent among those missing is Real Notch, an old Red Cliff Bay male who had an impressive record spanning three decades – both when it comes to consortships and also paternities. He will be sorely missed, but will live on in our memories, in scientific papers and in legend!
Another loss this year was Nicky, one of the regular visitors to Monkey Mia beach. She was probably one of the most well-known and most frequently photographed wild dolphins in the world. Her disappearance in June, just short of 40 years of age, has made international headlines and thousands of people have expressed their condolences over social media. She left behind her two and a half year old calf, Missel. While we were hopeful at first, she was last sighted a couple weeks after Nicky’s disappearance and has, unfortunately, not been sighted again since.
The dolphin society is changing! Many of the male alliances who have dominated the eastern gulf in recent years are slowly disappearing, existing alliances are changing, and we have identified several potential new alliances, with young male dolphins who might take the old alliances’ place in the years to come. Only time and continued survey effort will tell if they succeed. The 2016 season is just around the corner and we aim to make it as successful as 2015 has been.
Sam and Team East
One of the most famous of the Monkey Mia beach dolphins, Nicky (pictured above in 2005) died last month. She was just shy of her 40th birthday. Only a small percentage of dolphins in Shark Bay are lucky enough to live past 40 years of age. Nicky’s mother, Holey-fin, died this same month 20 years ago.
This video clip shows Nicky interacting with her first infant, Nipper, in 1988, when Nipper was just one year old. The interactions were filmed by Scott Crane, who was helping us out that year. Although the interaction appears very “cute”, with Nipper in “baby position” and nuzzling and rubbing against her mother, it reflects an infant trying to get attention from a mother who was more focused on the free fish available at Monkey Mia.
Nicky certainly wasn’t the best mother in the bay, and her only surviving offspring (pictured with her below as a youngster in 2012), now a juvenile, remains her only opportunity to leave a lasting legacy.
Her poor performance stands in stark contrast to other Monkey Mia females, like Puck and Surprise, who have been very successful and are now grandmothers. Nicky and Puck were born a year apart. Nicky was originally thought to be a male and was named Nick based on the large nick in her dorsal fin. Following the naming of Nick, A Midsummer Night’s Dream was the inspiration for Puck. The dolphin versions of Nick and Puck could not have had more different personalities, but in ways different from the play! Nicky was quite aggressive, while Puck (whose daughter and granddolphin are pictured below in 2012) has always had a sweet, gentle disposition.
See also Richard’s posting at https://www.facebook.com/dolphinallianceproject?fref=ts
The 2015 field season, with researchers Sam Wittwer and Teresa Borcuch on the Monkey Mia side (Dolphin Alliance Project) and Livia Gerber and Sonja Wild on the Useless Loop side (Dolphin Innovation Project), has been successfully kicked off.
Both teams (including PhD students, Masters students and volunteers from four different countries) will stay in the field until mid-October, collecting photo-identification, behavioural and genetic data. They’ll see oh-so-many dolphins, fascinating foraging and complex cooperation and competition… not to mention flying fish, sharks, rays, dugongs, turtles, birds, sea snakes, sun rises, sunsets and so on.
Interested in joining as a volunteer in future years? If so, please contact Michael, Richard or Simon.
sharkbaydolphins.org is finally online and provides you with news and updates about the exciting lives of the dolphins (and the humans lucky enough to study them) in the Shark Bay World Heritage Area of Western Australia.
We are pleased to announce the publication of “Male dolphin alliances in Shark Bay: changing perspectives in a 30-year study” in Animal Behaviour
Authors: Richard Connor and Michael Krützen
Abstract: Bottlenose dolphins, Tursiops cf. aduncus, in Shark Bay, Western Australia exhibit the most complex alliances known outside of humans. Advances in our understanding of these alliances have occurred with expansions of our study area each decade. In the 1980s, we discovered that males cooperated in stable trios and pairs (first-order alliances) to herd individual oestrous females, and that two such alliances of four to six, sometimes related, individuals (second-order alliances) cooperated against other males in contests over females. The 1990s saw the discovery of a large 14-member second-order alliance whose members exhibited labile first-order alliance formation among nonrelatives. Partner preferences as well as a relationship between first-order alliance stability and consortship rate in this ‘super-alliance’ indicated differentiated relationships. The contrast between the super-alliance and the 1980s alliances suggested two alliance tactics. An expansion of the study area in the 2000s revealed a continuum of second-order alliance sizes in an open social network and no simple relationship between second-order alliance size and alliance stability, but generalized the relationship between first-order alliance stability and consortship rate within second-order alliances. Association preferences and contests involving three second-order alliances indicated the presence of third-order alliances. Second-order alliances may persist for 20 years with stability thwarted by gradual attrition, but underlying flexibility is indicated by observations of individuals joining other alliances, including old males joining young or old second-order alliances. The dolphin research has informed us on the evolution of complex social relationships and large brain evolution in mammals and the ecology of alliance formation. Variation in odontocete brain size and the large radiation of delphinids into a range of habitats holds great promise that further effort to describe their societies will be rewarded with similar advances in our understanding of these important issues.
You can access the article at: http://www.sciencedirect.com/science/article/pii/S0003347215000810
We are very pleased to announce the publication of “Cultural transmission of tool use by Indo-Pacific bottlenose dolphins (Tursiops sp.) provides access to a novel foraging niche” in Proceedings of the Royal Society B.
Authors: Michael Krützen, Sina Kreicker, Colin D. MacLeod, Jennifer Learmonth, Anna M. Kopps, Pamela Walsham, and Simon J. Allen
Abstract: Culturally transmitted tool use has important ecological and evolutionary consequences and has been proposed as a significant driver of human evolution. Such evidence is still scarce in other animals. In cetaceans, tool use has been inferred using indirect evidence in one population of Indo-Pacific bottlenose dolphins (Tursiops sp.), where particular dolphins (‘spongers’) use marine sponges during foraging. To date, evidence of whether this foraging tactic actually provides access to novel food items is lacking. We used fatty acid (FA) signature analysis to identify dietary differences between spongers and non-spongers, analysing data from 11 spongers and 27 non-spongers from two different study sites. Both univariate and multivariate analyses revealed significant differences in FA profiles between spongers and non-spongers between and within study sites. Moreover, FA profiles differed significantly between spongers and non-spongers foraging within the same deep channel habitat, whereas the profiles of non-spongers from deep channel and shallow habitats at this site could not be distinguished. Our results indicate that sponge use by bottlenose dolphins is linked to significant differences in diet. It appears that cultural transmission of tool use in dolphins, as in humans, allows the exploitation of an otherwise unused niche.
Krützen M, Kreicker S, MacLeod CD, Learmonth J, Kopps AM, Walsham P, Allen SJ. 2014 Cultural transmission of tool use by Indo-Pacific bottlenose dolphins (Tursiops sp.) provides access to a novel foraging niche. Proc. R. Soc. B 281: 20140374. http://dx.doi.org/10.1098/rspb.2014.0374
We are pleased to announce the publication of the new paper “Cultural transmission of tool use combined with habitat specialisations leads to fine-scale genetic structure in bottlenose dolphins” in Proceedings of the Royal Society B.
Authors: Anna M. Kopps, Corinne Y. Ackermann, William B. Sherwin, Simon J. Allen, Lars Bejder and Michael Krützen
Abstract: Socially learned behaviours leading to genetic population structure have rarely been described outside humans. Here, we provide evidence of fine-scale genetic structure that has probably arisen based on socially transmitted behaviours in bottlenose dolphins (Tursiops sp.) in western Shark Bay, Western Australia. We argue that vertical social transmission in different habitats has led to significant geographical genetic structure of mitochondrial DNA (mtDNA) haplotypes. Dolphins with mtDNA haplotypes E or F are found predominantly in deep (more than 10 m) channel habitat, while dolphins with a third haplotype (H) are found predominantly in shallow habitat (less than 10 m), indicating a strong haplotype–habitat correlation. Some dolphins in the deep habitat engage in a foraging strategy using tools. These ‘sponging’ dolphins are members of one matriline, carrying haplotype E. This pattern is consistent with what had been demonstrated previously at another research site in Shark Bay, where vertical social transmission of sponging had been shown using multiple lines of evidence. Using an individual-based model, we found support that in western Shark Bay, socially transmitted specialisations may have led to the observed genetic structure. The reported genetic structure appears to present an example of cultural hitchhiking of mtDNA haplotypes on socially transmitted foraging strategies, suggesting that, as in humans, genetic structure can be shaped through cultural transmission.
Kopps AM, Ackermann CY, Sherwin WB, Allen SJ, Bejder L, Krützen M. 2014 Cultural transmission of tool use combined with habitat specialisations leads to fine-scale genetic structure in bottlenose dolphins. Proc. R. Soc. B 281: 20133245. http://dx.doi.org/10.1098/rspb.2013.3245