Category Archives: WSB

Jun 2019 – Social homophily in male dolphins, new paper in Proc Roy Soc B

Blurb: The beautiful and remote Shark Bay World Heritage Area (and Marine Protected Area) is home to the only known communities of tool-using dolphins on Planet Ocean. Only certain matrilines of dolphins engage in the tool-using behaviour, wearing basket sponges over the beaks/rostra as they forage. It’s thought to act as a protective ‘glove’ against sharp rocks, stingray barbs and the dorsal spines on some fish as the dolphins probe the sea floor.

There’s a general female-bias to this behaviour, with a much greater proportion of female calves adopting the behaviour her mum performs than do young males. This difference was long thought to be explained by the incompatibility of such a solitary and time-consuming behaviour with a male lifestyle – who should instead be investing time and energy into formulating alliances with other males.

Well, after a fateful survey in the western gulf of Shark Bay in May 2011, however, we discovered the existence of male alliances of sponging dolphins. About 8 years and two weeks later, here is the paper explaining this phenomenon.

Highlights: Diving into the behaviour of male dolphins that engage in tool-use for the first time and comparing them to non-tool-using males, we found that:

  • The male spongers spend more time associating with other male spongers than they do non-spongers, irrespective of relatedness or other factors.
  • They also devote more time to foraging and less time to resting and travelling than do non-sponging males.
  • Nevertheless, they spend just as much time socialising as do non-spongers.
  • Our study indicates social homophily in the second-order alliance composition of tool-using bottlenose dolphins.

Title: Tool use and social homophily among male bottlenose dolphins.

Authors: Bizzozzero MR, Allen SJ, Gerber L, Wild S, King SL, Connor RC, Friedman WR, Wittwer S, Krützen M.

Abstract: Homophilous behaviour plays a central role in the formation of human friendships. Individuals form social ties with others that show similar phenotypic traits, independently of relatedness. Evidence of such homophily can be found in bottlenose dolphins (Tursiops aduncus) in Shark Bay, Western Australia, where females that use marine sponges as foraging tools often associate with other females that use sponges. ‘Sponging’ is a socially learned, time-consuming behaviour, transmitted from mother to calf. Previous research illustrated a strong female bias in adopting this technique. The lower propensity for males to engage in sponging may be due to its incompatibility with adult male-specific behaviours, particularly the formation of multi-level alliances. However, the link between sponging and male behaviour has never been formally tested. Here, we show that male spongers associated significantly more often with other male spongers irrespective of their level of relatedness. Male spongers spent significantly more time foraging, and less time resting and travelling, than did male non-spongers. Interestingly, we found no difference in time spent socializing. Our study provides novel insights into the relationship between tool use and activity budgets of male dolphins, and indicates social homophily in the second-order alliance composition of tool-using bottlenose dolphins.  

Full citation: Bizzozzero MR, Allen SJ, Gerber L, Wild S, King SL, Connor RC, Friedman WR, Wittwer S, Krützen M. 2019 Tool use and social homophily among male bottlenose dolphins. Proc. R. Soc. B 286: 20190898. http://dx.doi.org/10.1098/rspb.2019.0898

Funding: This study was supported by a Swiss National Science Foundation grant 31003A_149956) to M.K. Further financial assistance was provided by grants from the National Geographic Society, W. V. Scott Foundation, Sea World Research and Rescue Foundation Inc., A. H. Schultz Stiftung, and the University of Zurich. S.L.K. was supported by The Branco Weiss Fellowship—Society in Science. W.R.F. was supported by a Graduate Fellowship in Anthropogeny from the University of California, San Diego.

Acknowledgements: We thank Shark Bay Resources and the Useless Loop community for their generous, long-term, in-kind and logistical support. We also thank all field assistants for their help during this study.

May 2019 – New paper in Ecology and Evolution

Title: Is MHC diversity a better marker for conservation than neutral genetic diversity? A case study of two contrasting dolphin populations.

Authors: Manlik O, Krützen M, Kopps AM, Mann J, Bejder L, Allen SJ, Frère C, Connor RC, Sherwin WB.

Abstract: Genetic diversity is essential for populations to adapt to changing environments. Measures of genetic diversity are often based on selectively neutral markers, such as microsatellites. Genetic diversity to guide conservation management, however, is better reflected by adaptive markers, including genes of the major histocompatibility complex (MHC). Our aim was to assess MHC and neutral genetic diversity in two contrasting bottlenose dolphin (Tursiops aduncus) populations in Western Australia — one apparently viable population with high reproductive output (Shark Bay) and one with lower reproductive output that was forecast to decline (Bunbury). We assessed genetic variation in the two populations by sequencing the MHC class II DQB, which encompasses the functionally important peptide binding regions (PBR). Neutral genetic diversity was assessed by genotyping twenty‐three microsatellite loci. 

We confirmed that MHC is an adaptive marker in both populations. Overall, the Shark Bay population exhibited greater MHC diversity than the Bunbury population—for example, it displayed greater MHC nucleotide diversity. In contrast, the difference in microsatellite diversity between the two populations was comparatively low.

Our findings are consistent with the hypothesis that viable populations typically display greater genetic diversity than less viable populations. The results also suggest that MHC variation is more closely associated with population viability than neutral genetic variation. Although the inferences from our findings are limited, because we only compared two populations, our results add to a growing number of studies that highlight the usefulness of MHC as a potentially suitable genetic marker for animal conservation. The Shark Bay population, which carries greater adaptive genetic diversity than the Bunbury population, is thus likely more robust to natural or human‐induced changes to the coastal ecosystem it inhabits.

Full citation: Manlik O, Krützen M, Kopps AM, Mann J, Bejder L, Allen SJ, Frère C, Connor RC, Sherwin WB 2019. Is MHC diversity a better marker for conservation than neutral genetic diversity? A case study of two contrasting dolphin populations. Ecology and Evolution 2019;00: 1-13 DOI: 10.1002/ECE3.5265

Funding: WV Scott Foundation; National Science Foundation, Grant/Award Number: 0918308, 0941487 and 1559380; Sea World Research and Rescue Foundation, Grant/Award Number: RM09107; NSERC; National Geographic Society; PADI Foundation; Australian Research Council; Shark Bay Shire; United Arab Emirates University.

Apr 2019 – Dolphins in hot water, new paper out in Current Biology

Feature image: This tiny calf of “Sunny”, a sponging mother dolphin in Shark Bay, did not make it to one year of age in the hard times following a marine heatwave.

 


Blurb: 
The remote and beautiful Shark Bay World Heritage Area (and marine park) got itself into some hot water in the summer of 2011. Various negative impacts across trophic levels followed this unprecedented marine heat wave, exacerbated by some anomalous flooding events, including the loss of habitat-forming seagrass meadows, crashes in invertebrate and fish populations, as well declines in marine turtle health.

For a little not-so-light reading, check out these prior papers by our friends and colleagues: Thomson et al. (2015). Extreme temperatures, foundation species, and abrupt ecosystem change: an example from an iconic seagrass ecosystem. Global Change Biology 21:1463–1474. And: Arias-Ortiz et al. (2018). A marine heatwave drives massive losses from the world’s largest seagrass carbon stocks. Nature Climate Change 8: 338–344.

Piccolo, daughter of Puck, is a famous Shark Bay dolphin. Here, she works hard to round up a bream in the shallows of Monkey Mia beach.

 

Highlights:This should probably read “lowlights” but, in this paper, we used our long-term demographic data to report on the subsequent (arguably cascading) effects of habitat degradation on the survival and reproduction of the iconic bottlenose dolphin population that inhabits this globally unique ecosystem.

Title: Long-term decline in survival and reproduction of dolphins following a marine heatwave. 

Authors: Sonja Wild, Michael Krützen, Robert W Rankin, Will JE Hoppitt, Livia Gerber, Simon J Allen.

Abstract: It’s a two-page correspondence piece, so there isn’t really an abstract per se, but here is the first paragraph, a pseudo-abstract of sorts: One of many challenges in the conservation of biodiversity is the recent trend in the frequency and intensity of extreme climatic events. The Shark Bay World Heritage Area, Western Australia, endured an unprecedented marine heatwave in 2011. Catastrophic losses of habitat-forming seagrass meadows followed, along with mass mortalities of invertebrate and fish communities. Our long-term demographic data on Shark Bay’s resident Indo-Pacific bottlenose dolphin (Tursiops aduncus) population revealed a significant decline in female reproductive rates following the heatwave. Moreover, capture–recapture analyses indicated 5.9% and 12.2% post heatwave declines in the survival of dolphins that use tools to forage and those that do not, respectively. This implies that the tool-using dolphins may have been somewhat buffered against the cascading effects of habitat loss following the heatwave by having access to a less severely affected foraging niche. Overall, however, lower survival has persisted post-heatwave, suggesting that habitat loss following extreme weather events may have prolonged, negative impacts on even behaviourally flexible, higher-trophic level predators.

 

Oakley and calf cruise over the seagrass and sand in western Shark Bay.

 

Full citation: Wild S, Krützen M, Rankin RW, Hoppitt WJE, Gerber L and Allen SJ. 2019. Long-term decline in survival and reproduction of dolphins following a marine heatwave. Current Biology 29: R1-R2. DOI: 10.1016/j.cub.2019.02.047

Funding and acknowledgements: This research was funded by grants from the Swiss Science Foundation, National Geographic Society, Sea World Research and Rescue Foundation, WV Scott Foundation and the AH Schultz Stiftung. We thank Mitsui, Shark Bay Resources, and the Useless Loop community for in-kind support, and field assistants for contributions to data collection. This research was conducted with scientific investigation permits from the Department of Biodiversity, Conservation and Attractions, as well as animal ethics approvals from the University of Zurich, University of Western Australia, Murdoch University and the University of New South Wales.

 

An alliance of males follows the foraging female in western Shark Bay. We hope we are not consigned to documenting the demise of the remarkable wildlife population.

 

Watch this space for more research findings in the coming months…

Jun 2018 – New publication on signature whistles in male alliances

The Dolphin Alliance Project and colleagues are pleased to announce the publication of our recent work on communication in Shark Bay’s “teams of rivals”, the male alliances…

Citation: King SL, Friedman W, Allen SJ, Gerber L, Jensen F, Wittwer S, Connor RC, Krützen M 2018. Bottlenose dolphins retain individual vocal labels in multi-level alliances. Current Biology https://doi.org/10.1016/j.cub.2018.05.013.

Field methods at a glance: A trio of dolphins forages in the shallows near Peron Peninsula. The research team confirms their identities with photo-identification, records their vocalisations with a four-hydrophone array and obtains aerial video with either a helikite- or a drone-mounted HD video camera (photo: Simon J Allen).

Summary: Cooperation between allied individuals and groups is ubiquitous in human societies, and vocal communication is known to play a key role in facilitating such complex human behaviours. In fact, complex communication may be a feature of the kind of social cognition required for the formation of social alliances, facilitating both partner choice and the execution of coordinated behaviours. As such, a compelling avenue for investigation is what role flexible communication systems play in the formation and maintenance of cooperative partnerships in other alliance-forming animals. Male bottlenose dolphins in some populations form complex multi-level alliances, where individuals cooperate in the pursuit and defense of an important resource: access to females. These strong relationships can last for decades and are critical to each male’s reproductive success. Convergent vocal accommodation is used to signal social proximity to a partner or social group in many taxa, and it has long been thought that allied male dolphins also converge onto a shared signal to broadcast alliance identity. Here, we combine a decade of data on social interactions with dyadic relatedness estimates to show that male dolphins that form multi-level alliances in an open social network retain individual vocal labels that are distinct from those of their allies. Our results differ from earlier reports of signature whistle convergence among males that form stable alliance pairs. Instead, they suggest that individual vocal labels play a central role in the maintenance of differentiated relationships within complex nested alliances. 

Figure 1 from the paper deftly illustrates the strength of social bonds between first- and second-order alliance partners, while the spectrograms display the whistle contours of each individual male dolphin (King et al. 2018). Note the differences between contours relative to the strength of particular social bonds.

Media: There was some very nice coverage from funders National Geographic (which you can view at: https://news.nationalgeographic.com/2018/06/dolphins-animals-courtship-friends/#), a great summary appeared in The Conversation (http://theconversation.com/male-dolphins-use-their-individual-names-to-build-a-complex-social-network-97780) and, 48 hours later, it’s pretty much everywhere!

BUBBLES! Are you talkin’ to me!? (photo: Simon J Allen)
Acknowledgements: Stephanie is a Branco Weiss Fellowship—Society in Science Fellow. Stephanie, Richard and Whitney received grants from the National Geographic Society. The study was also supported by a Swiss National Science Foundation grant to Michael. Whitney was supported by a Graduate Fellowship in Anthropogeny from the University of California, San Diego. Frants was supported by the US Office of Naval Research and a fellowship from the Aarhus Institute of Advanced Studies, Aarhus University. Permits for the scientific use of animals were obtained from the Department of Biodiversity, Conservation and Attractions (DBCA), Western Australia. The University of Zurich and University of Western Australia granted animal ethics approvals. The authors thank RAC Monkey Mia Dolphin Resort, Monkey Mia Wildsights, and the DBCA’s Shark Bay Rangers, all field assistants and our human judges for their help during this study. Lastly, we grateful to three anonymous reviewers for their valuable comments on the manuscript.
Stay tuned for some more exciting findings in the next few months.

Jan 2018 – The papers and presentations of 2017

Happy 2018! Time for a quick update: The last year has been a productive one for the Shark Bay Dolphin Research Alliance (SBDRA), with successful field seasons in both eastern (#36!) and western (#11) gulfs, a solid showing at the 22nd Biennial Conference in Halifax, Nova Scotia, and a number of papers published.

With field seasons wrapped up, we went on our way to Canada for the conference. Quite a few of us shared flights with other members of the group, plus colleagues from other labs. In various airports, we’d find the time to catch up and talk marine mammal science… oh wait. No, we wouldn’t. We’d just stare at our mobile devices…

 

 

Members of the SBDRA gave eight oral presentations and one poster presentation…

 

We also had a lovely ‘Friends of Shark Bay’ dinner for a gaggle of researchers past, present and future…

 

Amongst a few others, we published a paper on male alliance behaviour and mating access in the open social network of Shark Bay’s bottlenose dolphins (http://www.nature.com/articles/srep46354) in Nature’s Scientific Reports.

 

Also in Scientific Reports, another on sexual displays involving posturing and sponge presentation by male Australian humpback dolphins across north-western Australia (http://rdcu.be/w3tL).

 

There are so many intriguing parallels in behaviour and social complexity that exist between some of the cetacea and the great apes, but who would have thought that one charismatic, tool-using species might remain undiscovered until late 2017!? Congrats to Michael and colleagues on this wonderful result: http://www.cell.com/current-biology/fulltext/S0960-9822(17)31245-9.

 

2018 is shaping up to be a bumper year for papers and fieldwork. We look forward to sharing it with you, so stay tuned…

July 2017 – Field seasons start (and the Dolphin Alliance Project turns 35!)

The Shark Bay Dolphin Research Alliance field teams have now been back on the water for a month or so in Western Oz. This surely makes it time for a pictorial update of the first successes in pursuit of data on dolphins.

 

First things first, having kicked off in 1982, the Dolphin Alliance Project turns a healthy and productive 35 years old this season. Happy 36th field season DAP!

 

When packing for the field, there were a couple of team mascots a little concerned about whether or not they were joining us…

 

Indeed this day of departure image was no set-up – the door was left open and we came out to the project ute to find these rascals staking their claim…

 

One team went East (to Monkey Mia) with the hounds, while the other went West (to Useless Loop) with new team members and a recently serviced ‘Squidward’…

 

The Dolphin Alliance Project got amongst the action early, with popping males and foraging females on a glassy morning out…

 

The Dolphin Innovation Project got sampling on some glassy evenings in Useless Inlet…

 

And while Sonja did all the work driving and retrieving boats, Nahiid got busy with some serious shell photography (what a trooper!)…

 

Ol’ Bytfluke, the sponging grandmother, chasing brunch in a channel off Monkey Mia…

 

A trio of adult males from the 2nd-order alliance, the ‘Kroker Spaniels’, snagging near the pearl farm in Red Cliff Bay…

 

More of Stephanie’s acoustic targets, some of the ‘Hooligans’ alliance snagging in Whale Bight…

 

A beautiful young lady, Dokley, bow-riding in the shallows off Useless Loop…

 

Here is the delightful sponger Daiquiri in the Denham Channel, 2007…

 

And here she is, same fin, same old shark bite, same behaviour, same place, 2017…

 

Everyone’s favourite, the little boat-friendly Kimo in Useless Inlet…

 

And Kimo making photo-ID easy…

 

For those champing at the bit for an update on Osmo, the King of the Inlet, who lost his dorsal fin in a big fight over a female in 2016…

 

Here he is in 2017, looking cool, calm and healed…

 

And speaking of legends, here is the ‘Silver Bullet’ towing ‘Spongebob’ in the inaugural Dolphin Innovation Project season, 2007…

 

The end of an era, the last time the Bullet is used to launch the Bob before being handed over to a new owner (no, Silver Bullet has NOT crossed the rainbow bridge just yet)…

 

Of course, being in Shark Bay means some pretty sunsets. Sometimes it is important to ignore the rule of thirds…

 

Sunsets AND dolphins…

 

AGAIN!

 

In case people are getting bored with dolphins and sunsets, here are some BUDGIES!

 

For the picky/pedantic/thorough folk out there: photo credits go to the likes of Stephanie King, Nahiid Stephens, Sonja Wild and I of the Shark Bay Dolphin Research Alliance (Dolphin Alliance Project and Dolphin Innovation Project); image collection and other sampling/research was carried out under permit from WA Dept of Parks and Wildlife; and no doggies, dolphins or budgies were harmed in the making of this blog.

Jan 2017 – The Dolphin Innovation Project turns 10 (or ‘Not-so-Useless Loop 2007-2016’)!

1 Cover

The Shark Bay Dolphin Research Alliance is pleased to announce the successful navigation of a decade of dolphin research in the western gulf.

The first 10 seasons of the Dolphin Innovation Project’s field research have yielded some 4,500 dolphin group surveys, which have formed the basis of one Honours, six Masters and one PhD theses, with three more PhDs in the making. The data and subsequent analyses from the western gulf/Useless Loop study site have led to 11 peer-reviewed scientific journal articles in Frontiers in Marine Science, Marine Mammal Science, Marine Ecology Progress Series, Molecular Ecology, Proceedings of the Royal Society: Biological Sciences and more.

2 LIE3 shell

Along the way, we’ve identified over 60 sponging dolphins in the western gulf, discovered the function of shelling, and watched as a host of young males have galvanised into formidable second-order alliances. In recent seasons, we’ve added to ‘the usual suite’ of field techniques and started collecting underwater video records, laser photogrammetry data, helikite-mounted video and utilizing a hydrophone array.

We’re so very grateful to past field season leaders Alex Brown, Whitney Friedman, Livia Gerber, Anna Kopps, Dee McElligott, Krista Nicholson, and Sonja Wild; as well as a plethora of sterling volunteers/research assistants (from as far and wide as Australia, Brazil, Canada, England, France, Germany, Ireland, Italy, Scotland, Switzerland, the US of A and elsewhere), without whom such long-term projects would not be possible.

And hats off to David Allen/Wolf Design for the superb logo(s)!

Wolf Design Logo Red

We extend our sincere thanks to various funding agencies that have supported this research, the University of Zurich and, of-course, Shark Bay Resources and the Useless Loop community for being so accommodating to our teams.

Following are some of the changes to dolphins and kit over the last decade:

4 Scott 2007 Scott 5 Scott 2016 Scott

Scott the sponger 2007 and 2016

 

10 Emu 2007 Emu 11 Emu 2016 Emu

Emu the sponger 2007 and 2016

 

18 Porthos 2007 19 Porthos 2011 20 Porthos 2014 21 2016 Porthos

Porthos, one of two remaining Musketeers 2007, 2011, 2014 and 2016

 

And here is how the kit and storage has evolved from 2007 to 2016:

22 2007 Kit and storage 23 2017 kit and storage

 

We’ve seen some amazing things and shared great times. 2017 brings our 11th field season and we simply cannot wait to get back out there to catch up with old friends (finned and otherwise), observe, listen, experiment, innovate and discover… and, even though few of us are actually marine biologists, this seems like a fitting way to end the blog…

24 Astronauts

 

Nov 2016 – Part II: The Return of the King

…after Osmo’s bruising encounter, we had a day of searching for, but not finding, Floppy’s Crew. Then another windy stretch kept us off the water. Five days later we were back out there, and found Floppy, Splitfin and Sherman, another member of their second-order alliance, filling the space where Osmo should have been. They were involved in another social interaction with some females. Where was Osmo? Had he succumbed? Were Floppy and Splitfin that fickle!? Or is that just what it takes to be a successful male in this busy, competitive bay? No time for mourning a loss. The ‘new’ trio were regularly in formation behind the female.

26 Sherm 1 27 sherm 2

We went on the search for Osmo a few more times without luck, and Stephanie’s field season had come to an end. We left Shark Bay with a sense of foreboding, but hoped Sonja and her team, continuing for another two months, might have some good news for us down the track…

 

 

28 Osmo returns

Yesssss!!! About three weeks later, we finally got a long-awaited whatsapp message from Sonja and the team… “Can anyone help us ID this finless dolphin!?” Apparently the lads Floppy and Splitfin, still with other members of their second-order alliance, were involved in a bit of intense socialising action when a big finless fella came charging in… but then he held back and watched from the periphery. Discretion is the better part of valour! Here was Osmo, back, fin-less and healing.

Fast forward to early September when Sonja and I were back on the Bellefin Flats… who did we find? Floppy. Splitfin. And Osmo!

29 flop late30 split late31 osmo late

 

On our final day on the water in the western gulf for 2016, we headed down into Useless Inlet and found the big males, together, and consorting a female. Floppy was showing even more evidence of intense social interaction in recent times; We got a couple of celebratory leaps from Splitfin; And Osmo, off to the side. Foraging. The Return of the King!

32 split ouch 33 Split leap 34

 

Nov 2016 – Part 1: The Fellowship of the Inlet…

The dolphins of Shark Bay are famous for a number of reasons, not least of which is the strong tendency for adult males to form multi-level alliances in order to consort receptive females, compete against other alliances for access to females, and protect females from attacks by other alliances. In the feature photo above, the young fella Floppy, second from the left, mixes it (tho’ probably more as a spectator than a participant) with some of the big, well-established males on the Bellefin Flats in western Shark Bay in 2009.

By 2013, a first-order alliance of three lads, Floppy, Splitfin and Osmo seemed to be solidifying around the entrance to Useless Inlet (their bigger, second-order alliance known as “Floppy’s Crew”). 

2 Flop early3 Split1 Osmo key

We’ll never know whether Floppy and Splitfin’s superbly sculptured dorsal fin profiles are a result of shark bites or intense social interaction with other dolphins. “Rake marks” from the teeth of other dolphins are prevalent in these images. Osmo sports a distinctive dorsal keyhole.

The trio were a tight alliance by 2014 and 2015 field seasons. Here, Osmo has some rake marks from recent socialising; he surfaces close to Floppy; and Splitfin forages nearby.

5 Osmo key4 Osm and Flop6 split early

In early 2016, we found the now predictable and formidable trio consistently in and around the top half of Useless Inlet and the deeper channels near the dunes – Osmo now even more distinguishable with a deep tip-nick at the apex of his fin. Fairly typical of these guys (and many other first-order alliance trios), there often seems to be a tight pair and ‘the odd guy out’: Floppy and Splitfin the pair, Osmo the third wheel, but still never far. Synchrony in behaviours indicates a tight bond.

7 trio tight 19 Trio inlet 2 8 trio tight

Floppy’s Crew is one of Dr. King’s focal alliances, and here we were on a focal follow in the inlet shallows after Floppy, Splitfin and Osmo charged in and saw off some young males, then investigated the females with older calves.

10 focal follow

It seemed like every time we found these guys in 2016, Floppy and Splitfin would be tight together, travelling or resting, while Osmo would be off foraging. Longer dives. Unpredictable surfacing locations. This could make for a challenging and/or uneventful focal follow, but at least he was bulking up for winter! Being judgemental types, we started calling him ‘Osmo ate all the pies’.

12 Osmo pies

Then one evening, another trio (from the second-order alliance “The Baywatchers”) came purposefully in behind Floppy, Splitfin, Osmo and their lady-friend. Esther and his buddies, Doo and Caipirinha, surfaced synchronously behind our lads and their lady. The intent was clear… we’re here, we’re tight, and we’re interested…

13 Esther 14 Cai and Doo

We were stunned (and thoroughly impressed) to witness Osmo drop back a little behind Splitfin and Floppy, arch his back and flex hard, in a display with tail, head and open jaw out of the water (sorry, but I was just too slow on the trigger finger). He then positioned himself repeatedly between the approaching Baywatchers and the female. The Baywatchers soon backed off and Osmo, Floppy and Splitfin relaxed, their female retained. Osmo does eat all the pies, and he is the muscle… King of the Inlet!

15 mo flex 16 battle 1 17 trio lady

Later in June, we were surveying down into the inlet and we came across a wall of dolphins… they charged by us and it was clearly on – intense socialising between battling males over a female. As we tried to keep up with the melee, we started picking out recognisable fins. On some rapid surfacings, one big dolphin appeared finless. That individual surfaced consistently near Floppy and Splitfin… no, could it be…? On other surfacings, the freshly broken fin was ‘bouncing’ back upright… look! There is a tip-nick like Osmo’s (second from the left in the third image).

18 wall 19 broken 1 20 flappy

Ouch… that’s our big fella sporting an even-more-distinctive fin than that which he already had! Everything eventually calmed down, with the losing males moving back south into the inlet. Floppy, Splitfin and Osmo won the day, keeping the female Banquo… but at what cost?

21 Ouch 22 Losers 23 ouch 3

Banquo began foraging, while the lads followed slowly behind. Osmo then went back to some foraging of his own, but we thought he was moving pretty tenderly. We had to leave them at the end of the day, hoping we’d see them all again soon…

 

 

Oct 2016 – Another DIP field season comes to an end

Four months of fieldwork in the western gulf of Shark Bay saw generally poor field conditions in terms of wind and rain, but solid data collection none-the-less for both Ph.D. student Sonja Wild and Dr. Stephanie King. A big thanks to Research Assistants Helen Hiley, Sara Niksic, and Rebecca Cope for their time and effort. Following are some happy snaps from the season:

Stormy weather…2 Storm

A golden trivially makes its way up the food chain…3 Golden trevally end

Sherman shows off his healed shark bite and scans the shallows for fish…4 Sherman in the shallows

Caipirinha struts his stuff in front of a young male…5 Cai strut

Humphrey the Wonder Spaniel considers joining a male alliance…6 Humph n dolph

Pinata shows off her newborn calf…7 Pinata and Huitzilopochtli

Relaxing (snagging) with friends in Blind Strait…8 Snaggers

Little fins; big fin…11 Little dorsals big dorsal

Sublime South Passage…18 Sublime South Passage

Sunset on salt, the young Seamen and season #10…20 Sunset on salt

Watch this space for an update on the Dolphin Alliance Project’s 35th (!!) field season.