July 2017 – (Another) New paper in Scientific Reports

A short sail to the north-east (~700 nautical miles) of Shark Bay lies the shallow tropical seas of the Pilbara region. Other than oil and gas fields, there you’ll find a demersal trawl fishery and a faithful population of common bottlenose dolphins. Intrigued!? Learn more by clicking on (or copy-pasting into your browser) one of the links below:

Title: Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery

Authors: Simon J. Allen, Kenneth H. Pollock, Phil J. Bouchet, Halina T. Kobryn, Deirdre B. McElligott, Krista E. Nicholson, Joshua N. Smith & Neil R. Loneragan 

Link: Get your own piece of this action at http://rdcu.be/t5Y2 or www.nature.com/articles/s41598-017-05189-0

Highlights: *1. An aerial survey to estimate dolphin abundance in the PTF suggests population size is smaller than expected at somewhere between 2,000 and 5,000 individuals.   *2. As expected, boat-based photo-ID and genetic sampling suggest a community of dolphins show fidelity to trawler-associated foraging over days, weeks and years.   *3. Fisheries-related mortality events are likely to have an impact on the viability of a small dolphin population, but this cannot be demonstrated without more precise estimates of mortality rates (through an observer program) and/or further estimates of abundance (to detect trends).   *4. The tendency for the dolphins to exploit the fishery as a high-risk but efficient means of procuring resources is problematic for bycatch mitigation, as foraging “traditions” tend to be handed down from one generation to the next.   *5. The data presented here do, however, provide the basis for some further assessment of the level of impact that dolphin bycatch has on the population, through either the application of Potential Biological Removal estimation (as per the US system) or completing a Population Viability Analysis.

Abstract: The incidental capture of wildlife in fishing gear presents a global conservation challenge. As a baseline to inform assessments of the impact of bycatch on bottlenose dolphins (Tursiops truncatus) interacting with an Australian trawl fishery, we conducted an aerial survey to estimate dolphin abundance across the fishery. Concurrently, we carried out boat-based dolphin photo-identification to assess short-term fidelity to foraging around trawlers, and used photographic and genetic data to infer longer-term fidelity to the fishery. We estimated abundance at ≈ 2,300 dolphins (95% CI = 1,247–4,214) over the ≈ 25,880-km2 fishery. Mark-recapture estimates yielded 226 (SE = 38.5) dolphins associating with one trawler and some individuals photographed up to seven times over 12 capture periods. Moreover, photographic and genetic re-sampling over three years confirmed that some individuals show long-term fidelity to trawler-associated foraging. Our study presents the first abundance estimate for any Australian pelagic dolphin community and documents individuals associating with trawlers over days, months and years. Without trend data or correction factors for dolphin availability, the impact of bycatch on this dolphin population’s conservation status remains unknown. These results should be taken into account by management agencies assessing the impact of fisheries-related mortality on this protected species.

 

1: Aerial survey tracks across the Pilbara Trawl Fishery management areas, north-western Australia, and dolphin group sightings.

 

2: Boat-based photo-identification reveals a community of dolphins, like this mother and calf, that regularly follow trawlers over days and weeks, feeding on injured or discarded fish. Sharks also follow the trawlers scavenging on discards, like the sizeable whaler pictured her below the dolphins.

 

3: Locations and times between sampling events of dolphins around trawlers. Genetic re-sampling and opportunistic photo-ID confirmed that some dolphins also follow the trawlers in the Pilbara over months and years.

 

4: Aggregations of dolphins follow the trawlers day-in day-out, leading to the impression that the population as a whole is large, but these preliminary results indicate that the population is smaller than expected.

 

5: This newborn is likely to learn about foraging around trawlers from its mother. Unfortunately the level of risk associated with foraging in and around fishing nets is not so easily taught.

All figures are from the paper in Scientific Reports and all images are ©Simon Allen.  🙂

Funding and acknowledgements: The Australian Marine Mammal Centre was the primary funder of this research, with additional contributions from the Fisheries Research and Development Corporation, the Western Australian Department of Fisheries, and the Nickol Bay Professional Fishers Association. We thank the commercial trawl operators for in-kind support and acknowledge the logistical assistance provided by the skippers and crews of the Pilbara Fish Trawl Interim Managed Fishery. Amanda Hodgson and Maria Jedensjö were instrumental in helping design and conduct the aerial survey, respectively. The research was carried out under cetacean research permits from both the Western Australian State Government and the Australian Commonwealth Government. Dolphin tissue samples were transferred to the University of Zurich under CITES using institutional permits for scientific exchange, and the research was conducted with animal ethics committee approval from Murdoch University.

 

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.

Apr 2017 – New paper on alliances published in Nature’s Scientific Reports

 

Title: Male alliance behaviour and mating access varies with habitat in a dolphin social network

Authors: Richard C. Connor, William R. Cioffi, Srđan Randić , Simon J. Allen, Jana Watson-Capps & Michael Krützen

Highlights: We discovered that male dolphin alliance behaviour varies systematically along the Peron Peninsula in the World Heritage Listed Shark Bay, Western Australia. It is rare to find such variation in a single population of mammals, and indeed even more so in a single social network. This exciting discovery was made by pure serendipity, as often happens in science. We set out to work on a completely different issue, and discovered this!

Abstract: Within-species variation in social structure has attracted interest recently because of the potential to explore phenotypic plasticity and, specifically, how demographic and ecological variation influence social structure. Populations of bottlenose dolphins (Tursiops spp.) vary in male alliance formation, from no alliances to simple pairs to, in Shark Bay, Western Australia, the most complex nested alliances known outside of humans. Examination of ecological contributions to this variation is complicated by differences among populations in other potentially explanatory traits, such as phylogenetic distance, as well as female reproductive schedules, sexual size dimorphism, and body size. Here, we report our discovery of systematic spatial variation in alliance structure, seasonal movements and access to mates within a single continuous social network in the Shark Bay population. Participation in male trios (versus pairs), the sizes of seasonal range shifts and consortship rates all decrease from north to south along the 50 km length of the study area. The southern habitat, characterised by shallow banks and channels, may be marginal relative to the open northern habitat. The discovery of variation in alliance behaviour along a spatial axis within a single population is unprecedented and demonstrates that alliance complexity has an ecological component.

 

2 Figure 1

Figure 1: The study site in waters off the east side of Peron Peninsula, which bisects Shark Bay, Western Australia. Centroids for seven northern 2nd-order alliances, which occupy relatively open habitat, are shown divided from the five southern 2nd-order alliances, which occupy habitat subdivided by shallow banks and channels.

 

3 Figure 2

Figure 2: The proportion of trios (triangles), consortship rate (circles), and adjusted consortship rate (squares) in 2nd-order alliances decreases in a SE direction across the study area/two habitats. Fitted logistic curves are shown from generalized linear models. prop. trios = proportion trios, CR = consortship rate.

Citation: Connor, R.C. et al. 2017 Male alliance behaviour and mating access varies with habitat in a dolphin social network. Sci. Rep. 7, 46354; doi: 10.1038/srep46354.

Link: http://www.nature.com/articles/srep46354

Acknowledgements: This study was supported by grants from the Australian Research Council (A19701144 and DP0346313), The Eppley Foundation for Research, The Seaworld Research and Rescue Foundation, The W. V. Scott Foundation, The National Geographical Society’s Committee for Research and Exploration and NSF (1316800). Accommodation was very generously provided by the Monkey Mia Dolphin Resort. Permits for the scientific use of animals were obtained from the West Australian Department of Parks and Wildlife. The University of Massachusetts at Dartmouth approved this study. Many generous people helped make this project possible. Landsat 7 ETM+ imagery of Shark Bay courtesy of the U.S. Geological Survey.

Feb 2016 – New paper (moonlighting to the north) in Endangered Species Research

About 400 km to the north of our wondrous focal study site of Shark Bay lies the spectacular Ningaloo Reef and North West Cape. Some of our initial field efforts to study bottlenose and humpback dolphins up that way have involved collecting data that has already contributed to several papers (see Allen et al. 2012 and 2016, and Brown et al. 2012 and 2014 on the publications page, for example). We then obtained some funding from the Australian Marine Mammal Centre (to PI Guido Parra of Flinders Uni, and Co-Is Lars Bejder and Simon Allen) to look specifically at Australian humpback dolphin (Sousa sahulensis) ecology, and a PhD was taken on by Tim Hunt. That research is now coming to fruition, with Tim’s PhD nearing completion and his first thesis data paper hot off the (online) press.

Title: Demographic characteristics of Australian humpback dolphins reveal important habitat toward the south-western limit of their range

Authors: Tim N Hunt, Lars Bejder, Simon J Allen, Rob W Rankin, Daniella Hanf, Guido J Parra.

1 simo

An adult Australian humpback dolphin off the North West Cape, Western Australia.

 

Highlights: 

  • Our very own Australian humpback dolphins were only classified as a separate species from their south-east Asian cousins as recently as 2014. Given their somewhat cryptic nature and their distribution across Australia’s remote northern coastline, they remain elusive to the extent that we do not have enough information to assign them a conservation status (other than ‘data deficient’).
  • In this study, we sought to estimate the abundance, site fidelity and residence patterns of Australian humpback dolphins around the North West Cape, Western Australia.
  • We estimated a population of 129 individuals in the 130 km² study area and documented the highest density recorded for this species to date. Incidentally, we also documented almost double that number of Indo-Pacific bottlenose dolphins in the study area, but that remains for a future study/publication.
  • The density, site fidelity and residence patterns of Aussie humpback dolphins around the North West Cape suggest it is an important habitat for the species.
  • We provide a methodological framework for future Impact Assessments and a baseline for longer-term studies on this enigmatic species.

 

2 simo copy

Cumulative discovery curve of identified Australian humpback dolphins (n = 98) within the North West Cape study area over the 2013, 2014 and 2015 survey periods (total 195 d).

 

Abstract: The paucity of information on the recently described Australian humpback dolphin (Sousa sahulensis) has hindered assessment of its conservation status. Here, we applied capture-recapture models to photo-identification data collected during boat-based surveys between 2013 and 2015 to estimate the abundance, site fidelity and residence patterns of Australian humpback dolphins around the North West Cape (NWC), Western Australia (WA). Using Pollock’s Closed Robust Design, abundance estimates varied from 65 to 102 individuals, and POPAN open modelling yielded a super-population size of 129 individuals in the 130 km² study area. At approximately one humpback dolphin per km², this density is the highest recorded for this species. Temporary emigration was Markovian, suggesting seasonal movement in and out of the study area. Hierarchical clustering showed that 63% of individuals identified exhibited high levels of site fidelity. Analysis of lagged identification rates indicated dolphins use the study area regularly over time, following a movement model characterized by emigration and re-immigration. These density, site fidelity and residence patterns indicate that the NWC is an important habitat toward the south-western limit of this species’ range. Much of the NWC study area lies within a Marine Protected Area, offering a regulatory framework on which to base the management of human activities with the potential to impact this threatened species. Our methods provide a methodological framework to be used in future environmental impact assessments, and our findings represent a baseline from which to develop long-term studies to gain a more complete understanding of Australian humpback dolphin population dynamics.

Full citation: Hunt TN, Bejder L, Allen SJ, Rankin RW, Hanf D, Parra GJ. 2017. Demographic characteristics of Australian humpback dolphins reveal important habitat toward the south-western limit of their range. Endangered Species Research 32: 71-88.

3 simo

Socialising humpback dolphins. Note the scarred dorsal fin of an adult male and the long beak of the other individual – classic Australian humpback dolphin characteristics.

 

Funding and acknowledgements: The Australian Marine Mammal Centre (Project 12/11) and the Winifred Violet Scott Charitable Trust funded this research. We sincerely thank all ‘Team Sousa’ volunteers that assisted with data collection in the field over the 3 years of surveys. Data collection was permitted by the WA Department of Parks and Wildlife (DPaW; SF009240, SF009768, SF010289), WA Department of Agriculture and Food (U38/2013-2015) and the Australian Government Department of Defence (Harold Holt Naval Base Exmouth), with approval from Flinders University Animal Welfare Committee (E383). We would also like to thank the community and businesses of Exmouth, the staff at DPaW Exmouth, the Cape Conservation Group, and MIRG Australia for supporting the North West Cape Dolphin Research Project. We thank Ken Pollock for providing initial statistical advice on earlier versions of this manuscript.

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 – A review paper in Biology Letters

Woohoo! Not long after our publications in Animal Cognition and Marine Mammal Science, Dr. Stephanie King and a colleague have a review in Biology Letters on vocal matching in animals.

Title: Vocal Matching: the what, the why and the how.

Authors: Stephanie King and Peter McGregor.

Abstract: Over the years, vocal matching has progressed beyond being an interesting behavioural phenomenon to one that now has relevance to a wide range of fields. In this review, we use birds and cetaceans to explain what vocal matching is, why animals vocally match and how vocal matching can be identified. We show that while the functional aspects of vocal matching are similar, the contexts in which matching is used can differ between taxa. Whereas vocal matching in songbirds facilitates mate attraction and the immediate defence of resources, in parrots and cetaceans it plays a role in the maintenance of social bonds and the promotion of behavioural synchrony. We propose criteria for defining vocal matching with the aim of stimulating more matching studies across a wider range of taxa, including those using other, non-vocal, communication modalities. Finally, we encourage future studies to explore the importance of vocal learning in the development of vocal matching, and the information it may provide to third parties in the communication network.

Key words: songbirds; cetaceans, vocal matching; vocal learning; interactive playbacks.

You can access the article at http://rsbl.royalsocietypublishing.org/content/12/10/20160666.full.

Nov 2016 – Piccolo’s piscatorial penchant

In 2005, Piccolo (the dolphin) brought the people (who normally feed her) at Monkey Mia a sizeable pink snapper. Despite having it handed back to her by rangers, she insisted. Pay-back for years of free hand-outs?

1

Fast forward to 2016 and she still has some adept foraging skills. As for the hapless snapper, ever get the feeling you’re being watched?:

3

A little burst of acceleration and some hydroplaning:

4

She pivots… the jaws of death await… a near miss:

5

 

At this point, it still seems reasonably fair… the fish has a chance of escape in the shallows, right?:

6

Aargh! 150 kg grey torpedo armed with tens of teeth out there and the mighty winged shadow of death with a huge beak in here? Utterly unfair:

7

Piccolo at risk of losing her well-rounded (up) meal… Flee fishy! …an even nearer miss:

9

…but… game over. Piccolo 1: Pelican 0: Pisces -1:

10

 

 

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.