Category Archives: Publication Announcements

May 2016 – New publication in Molecular Ecology

Hot on the heels of our recent publication in Frontiers (see: Rankin R, Nicholson K, Allen S, Krützen M, Bejder L, Pollock K (2016). A full-capture Hierarchical Bayesian model of Pollock’s closed robust design and application to dolphins. Frontiers in Marine Science 3: 25. DOI: 10.3389/fmars.2016.00025), we are very pleased to announce the publication (online early view) of our most recent paper in Molecular Ecology:

Title: Genetic isolation between coastal and fishery-impacted, offshore bottlenose dolphin (Tursiops spp.) populations.

Authors: Simon Allen, Kate Bryant, Robert Kraus, Neil Loneragan, Anna Kopps, Alex Brown, Livia Gerber and Michael Krützen.

Abstract: The identification of species and population boundaries is important in both evolutionary and conservation biology. In recent years, new population genetic and computational methods for estimating population parameters and testing hypotheses in a quantitative manner have emerged. Using a Bayesian framework and a quantitative model-testing approach, we evaluated the species status and genetic connectedness of bottlenose dolphin (Tursiops spp.) populations off remote northwestern Australia, with a focus on pelagic ‘offshore’ dolphins subject to incidental capture in a trawl fishery. We analysed 71 dolphin samples from three sites beyond the 50 m depth contour (the inshore boundary of the fishery) and up to 170 km offshore, including incidentally caught and free-ranging individuals associating with trawl vessels, and 273 dolphins sampled at 12 coastal sites inshore of the 50 m depth contour and within 10 km of the coast. Results from 19 nuclear microsatellite markers showed significant population structure between dolphins from within the fishery and coastal sites, but also among dolphins from coastal sites, identifying three coastal populations. Moreover, we found no current or historic gene flow into the offshore population in the region of the fishery, indicating a complete lack of recruitment from coastal sites. Mitochondrial DNA corroborated our findings of genetic isolation between dolphins from the offshore population and coastal sites. Most offshore individuals formed a monophyletic clade with common bottlenose dolphins (T. truncatus), while all 273 individuals sampled coastally formed a well-supported clade of Indo-Pacific bottlenose dolphins (T. aduncus). By including a quantitative modelling approach, our study explicitly took evolutionary processes into account for informing the conservation and management of protected species. As such, it may serve as a template for other, similarly inaccessible study populations.

The full citation is Allen SJ, Bryant K, Kraus R, Loneragan N, Kopps A, Brown A, Gerber L, Krützen M (2016). Genetic isolation between coastal and fishery-impacted, offshore bottlenose dolphin (Tursiops spp.) populations. Molecular Ecology doi: 10.1111/mec.13622

You can find the paper at URL: http://onlinelibrary.wiley.com/doi/10.1111/mec.13622/full

 

 

May 2015 – New Publication in Animal Behaviour

ESBDolphin BB flank female

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

Apr 2014 – Another publication in Proceedings of the Royal Society B

WSBDolphin Fajita with sponge 2

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

Feb 2014 – New publication in Proceedings of the Royal Society B

WSBDolphin Liesa with#25305662

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