A Field Season of Basking Shark Research in the Sea of Hebrides 2019

This summer, a team from the University of Exeter have been on field work in the Inner Hebrides tracking and filming basking sharks! Read on to find out why…

Words by Owen Exeter, Christopher Kerry and Jessica Rudd.

Basking sharks are the world’s second largest fish and one of the UK’s most iconic marine species. Understanding the lives of these endangered fish is key to their conservation. Since 2012, researchers from the University of Exeter led by Dr Matthew Witt and Dr Lucy Hawkes in collaboration with Scottish Natural Heritage’s Dr Suzanne Henderson have been working in the Sea of Hebrides to understand how and why sharks use these coastal waters. This year the team are applying a variety of technologies to investigate the secret life of basking sharks below the surface.

Left: Dr Suzanne Henderson, Dr Lucy Hawkes and Dr Matthew Witt. Right: Image taken by REMUS.

Previously, most of our knowledge of basking shark spatial ecology and behaviour has relied on surface observations limited by daylight and weather conditions. With the recent advances of tracking technologies, we have gained unprecedented insight into their UK distribution, diving behaviour, long distance migration and inter-annual site fidelity. Satellite telemetry data acquired by the Exeter team have confirmed the waters off the Isles of Coll and Tiree as spatially important to the species (Doherty et al. 2017). These findings have directly informed conservation management with the proposed Sea of the Hebrides MPA currently under consultation.

Recently the team’s research has shifted to exploring whether the region has further significance to the species. Little is known about basking shark reproductive behaviour, fine-scale movement or habitat preference. 2017 saw the successful deployment of multichannel tags recording behaviour at the sub-second level (Rudd et al. in prep) and in 2018, custom made cameras designed by MR ROV started elucidating some of these questions. This year we were joined by a team from Woods Hole Oceanographic Institute (WHOI) and their Autonomous Underwater Vehicle (AUV) REMUS, with further towed cameras to deploy and a sonar scanner to attempt to shed further light on the rarely seen secret life of basking sharks.

Field site: Isles of Coll and Tiree, Inner Hebrides, Scotland.

Woods Hole Oceanographic Institute REMUS

REMUS is an AUV, a two-meter-long submersible vehicle that is designed to record underwater footage without manual controls from the surface. This allowed us to conduct long deployments at distances of over 2km from our control boat. Developed by Amy Kukuyla and her team at WHOI, REMUS has previously been deployed to film white sharks, bull sharks and leatherback turtles at depth.

As REMUS relies upon a tracking beacon tag being attached to the sharks half our team set off early from Tobermory harbour to locate and deploy tags aboard vessel Bold Ranger. The control team, including WHOI staff, followed on Etive Explorer. We successfully deployed beacons on multiple sharks across several days. Once tagged, we launched REMUS which followed the sharks at predetermined distances for up to four hours each mission. REMUS has 5 frontal cameras with an optional rear camera allowing near 360 views to be captured and up to 24 hours of footage generated per mission. Members of the team are currently stitching these different camera views together for each mission to allow further processing and analysis of the footage.

Left: REMUS. Right: MR ROV towed camera.

Towed camera deployment

Last summer, the towed cameras revealed new and exciting footage, including the very first shark aggregation observed on the seabed. While basking sharks may aggregate at the surface to feed, it remains unclear why they may do so at depth. Wanting to build upon these initial findings and hope to uncover more novel behaviour, this year we set out to re-deploy three cameras for a longer duration. These tags encase a temperature-depth recorder tracking the shark’s movement throughout the water column while filming it with a rear and front facing camera attached just below the dorsal fin by a 1.5 m tether. A vital component to the tag package is the Programmed Time Release which enables us to set the time at which we wish the camera to pop off the shark after a desired period and an integrated satellite tag, allowing us to track the camera remotely once its antennae breaks the surface by relaying its position every hour.

Footage acquired from 2018 MR ROV towed cameras.

This season the team was again successful in deploying all three camera tags. Upon release we deployed a range of tech to help us successfully hone into the position of the cameras. Once arrived at its last known coordinates, we used a goniometer which gave an idea of the bearing of the camera in relation to the boat. Within a certain range a handheld VHF radio (above the surface) as well as a VEMCO acoustic pinger (underwater) provide extra confidence in the directionality and distance to our prized tags.

While two of the sharks remained close to Coll, the third shark swum towards the Isle of Harris in the Outer Hebrides, nearly 150km north of it’s initial attachment. After a stroke of luck, a skipper and boat were found to help locate the last tag, known as Mr ROV Green, but required us to leave Mull, cross the mainland and drive across Skye before being picked up by a rib to find the camera. With the final mission successfully completed and all three camera tags found, now comes the exciting part of reviewing footage from both the cameras and REMUS to discover what new behaviours may have been recorded, along with answering biologically important questions such as estimating feeding rates and tail beat frequencies, as well as possible interactions with other basking sharks.

Finally, we would like to say a big thank you to Matt, Lucy and Suz for their knowledge and support during this field season. Interacting with a range of field technologies and seeing our data feed directly into policy and management is an invaluable experience for early career researchers. This work wouldn’t be possible without their hard work and dedication. We would also like to extend our thanks to Sky Ocean Rescue, WWF and Scottish Natural Heritage for their support of the project.

If you would like to updates on the basking shark project and our team’s other research please follow via twitter: Owen @OExeter,  Chris @chriskerry1989  and Jess @jlrudd.

The team. Clockwise from top left: Dr Lucy Hawkes, Dr Matt Witt, Owen Exeter, Chris Kerry and Jessica Rudd

#ExeterMarine is an interdisciplinary group of marine related researchers with capabilities across the scientific, biological,  medical, engineering, humanities and social science fields.

Find us on: Facebook : Twitter : Instagram : LinkedIn  

If you are interested in working with our researchers or students, contact Michael Hanley or visit our website!

My Exeter PhD: Camouflage helps brightly coloured chameleon prawns to survive in the rock pools

Camouflage is vital to an animals survival, blending in to the background can stop you being spotted by predators or conversely, allow you to sneak up on your prey. But how do animals that live in highly variable environments like rockpools, where the surrounding plant life and available hide-y holes can change from one tide to the next, stay camouflaged? One option to has a variety of colour morphs like the chameleon prawn found in UK rockpools, but what happens if you suddenly find yourself in a pool predominately full of green seaweed when you are bright red?

University of Exeter PhD student Sam Green tells us about his new paper with the Sensory Ecology Evolution Group, working to understand the drivers of variation in the chameleon prawn colour variation.

Words by Sam Green, PhD Student, University of Exeter.

Key findings: Brightly coloured and aptly named chameleon prawns (Hippolyte varians) combine impressive changes in colour with behavioural preferences for particular seaweeds to survive in their rock pool habitats.

Here in Cornwall we are lucky to have easy access to incredibly diverse rock pools around our coastline that are teaming with wildlife. One fascinating species dwelling amongst the seaweeds close to the low tide line is the chameleon prawn (Hippolyte varians). An apt name for a species that is highly variable in appearance and found in forms ranging from vibrant red and green colours to varying degrees of transparency and patterning1,2. But what is driving this remarkable variation?

 

Chameleon prawns (Hippolyte varians) are found in an incredible diverse range of vibrant colour forms in UK rock pools.

Rock pools are extremely beautiful and colourful environments but they are challenging to live in.  Every day the tides’ ebb and flow, which changes the availability of submerged habitat as well as the varieties of predators that range over the rock pools looking for an easy meal. Could this variation in colour help prawns to avoid the interests of hungry fish? One possibility is that prawn coloration provides camouflage against their seaweed substrates. But how can they maintain this camouflage when the rock pool environment is so variable and always changing?

Natural habitats comprise many potential background colours, posing a challenge for any animal that relies on camouflage – such as this array of seaweeds in a rock pool.

One remarkable camouflage strategy that might be used is for an animal to change body coloration itself. This is surprisingly common in the natural world with the duration of change ranging from a few seconds to weeks and months3. The well-known masters of this strategy include octopus and cuttlefish, where many are capable of swift changes to their coloration enabling them to quickly tailor their camouflage to the surroundings4. Might chameleon prawns also utilise colour change to better match their surroundings?

In our research we have focused on green and red chameleon prawns and their seaweed substrates, the green sea lettuce and red dulse. We brought prawns and seaweed into the lab and housed the prawns on seaweed of opposing coloration. Then, analysing coloration of prawns and seaweed from the perspectives of predatory fish visual systems, we measured changes in colour in relation to camouflage.

 

Chameleon prawns were kept individually on seaweed of mismatching coloration in the lab to induce colour change.

Prawns have an excellent level of camouflage against their associated substrate types. They are also capable of impressive, if somewhat slow, colour changes that drastically improve camouflage against the previously mismatching seaweed over a number of weeks. So the prawns can change colour, but it’s clearly too slow to maintain camouflage when swimming around the rock pools. The seaweeds that comprise the ‘algal forests’ of the intertidal zone vary with the seasons5. These slower colour changes probably enable prawns to capitalise on seasonal seaweed shifts, whilst still benefiting from the protection of camouflage. If this is the case, how do the prawns maintain camouflage on a day-to-day basis?

Examples of the remarkable changes in colour displayed by green and red prawns over the 30 day experiment.

Animals often improve their camouflage through behaviour, such as choosing appropriate backgrounds that maximise their camouflage6.  Again using the same two species of seaweed we tested the behavioural preferences of green and red chameleon prawns. The prawns display strong behavioural preferences for selecting a background that best compliments their own coloration. So, whilst colour change may be of no use if a passing wave were to dislodge a prawn from its chosen camouflaged perch, they are able to quickly rectify the issue by swimming to the nearest patch of suitable seaweed.

The behavioural choice chamber used in our study. Here a red prawn chooses between suitable seaweed backgrounds.

The act of remaining camouflaged is rarely as simple as it first appears. The incredible variation in body coloration displayed by chameleon prawns enables the highest level of camouflage against particular seaweed backgrounds. On top of that the prawns display clear adaptations for remaining obscured in their environment, despite the challenges presented by their rock pool existence. For the chameleon prawns, our research shows that perhaps the best way of maintaining camouflage in the face of variation is to have a suite of strategies to suit the occasion.

Chameleon prawns are extremely well camouflaged against their favoured seaweed backgrounds. As seen here with green prawns and green sea lettuce.

Read the paper here

You can follow Sam on Twitter: @saunteringsam and Instagram: @saunteringsam

You can also keep up to date with the Sensory Ecology and Evolution Lab on Instagram: @See_research_lab and Facebook

References:

  1. Gamble, F. W. & Keeble, F. W. Hippolyte varians: a Study in Colour-change. Q. J. Microse Sci. 43, 589–703 (1900).
  2. Keeble, F. W. & Gamble, F. W. The colour-physiology of Hippolyte varians. Proc. R. Soc. London 65, 461–468 (1899).
  3. Duarte, R. C., Flores, A. A. V, Stevens, M. & Stevens, M. Camouflage through colour change : mechanisms , adaptive value and ecological significance. (2017). doi:10.1098/rstb.2016.0342
  4. Hanlon, R. Cephalopod dynamic camouflage. Curr. Biol. 17, 400–404 (2007).
  5. Dickinson, C. British Seaweeds – The Kew Series. (Eyre & Spottiswood, 1963).
  6. Stevens, M. & Ruxton, G. D. The key role of behaviour in animal camouflage. Biol. Rev. (2018). doi:10.1111/brv.12438

#ExeterMarine is an interdisciplinary group of marine related researchers with capabilities across the scientific, biological,  medical, engineering, humanities and social science fields.

Find us on: Facebook : Twitter : Instagram : LinkedIn  

If you are interested in working with our researchers or students, contact Michael Hanley or visit our website!

 

Nocturnal Flamingo Behaviour

Author: Dr. Paul Rose

 

We know a lot about the behaviour of wild species during the daytime and behaviour studies on animals in human care are often used to help inform us of their welfare state. For lots of species housed in zoological collections, we know little about what they do once their keepers go home. To fully understand their behaviour patterns, and what goes on when we’re not watching, we can use technology to observe their behaviour patterns across a full 24 hour cycle.

It’s commonplace to use data from the wild to help explain what our animals are doing in captivity. For species that might be just as active during the night as well as during the day, our observations on a human time-frame might only be half of the story. As more research is published on the ecology of wild species, this can be used to inform how we keep species in zoological collections- and knowledge of the nocturnal habits of “diurnal” species is one such area of scientific investigation.

 

The flamingo enclosure at WWT Slimbridge Wetland Centre

 

This research focused on flamingos, one of the world’s most popular of zoo animals occurring in a huge number of animal collections globally. Wild studies of flamingos have noted that feeding and foraging, chick rearing and movements between feeding and breeding areas can occur overnight. But how active are zoo birds? Will they still follow a similar activity budget to that shown in the field?

Using several remote trail cameras, fitted around the enclosure of a large flock of around 270 greater flamingos housed at WWT Slimbridge Wetland Centre behaviour across both day and night was collected over spring and summer 2016. The bird’s enclosure was split into different habitats areas, based on water depth in their pool and land areas used for different behaviour (such as nesting and rearing young) to see if areas commonly utilised during the daytime were still used overnight.

 

 

Shots taken directly from remote cameras stationed around the flamingo enclosure taken during the day (above), and at night (below).

 

Remote cameras are great for capturing behaviour in the wild and in the zoo. They reduce the chance of a human observer affecting or influencing the behaviour of the animal being watched. And they can be set to record animals at specific times, to focus on what animals might be doing over different seasons or times of day. And they can help collect data to inform animal welfare standards by providing a picture of how animals use their space and what areas of their habitat they prefer to be in.

Results show that these flamingos use their enclosure differently at night to that seen in daytime. Foraging behaviours peaked in the evening, showing that even though the flamingos are provided with a complete diet, natural filtering in their pool is still an important behaviour for these birds to perform.

Widest enclosure use, with the largest number of birds using the maximum number of zones was seen during the later evening, middle of the night and into the early morning. Birds congregated in fewer areas of their habitat during the later morning and middle of the day- preferring to be in one specific place for resting and preening.

Some behaviours were more commonly performed during daylight- courtship display for example peaks in the morning, and is lowest overnight. Showing that for some behaviours with a high visual impact, time of day for its performance is important for the message being presented by the behaviour.

 

 

This research has important implications for how we manage zoo populations of flamingos and other species in animal collections. These nocturnal observations show us the times in a day when flamingos naturally spend their time on key behaviours. By providing a habitat that allows a range of activities to be performed at different times, and not restricting the birds space to use these areas means that in a zoological collection, a natural behaviour pattern is performed. This is important for the welfare of these birds as the good features of this enclosure (its large size, the range of habitat areas, and the large number of birds housed within it) can be replicated in other zoological institutions to provide the highest quality of life possible.

We also show the influence of season on overall flock nocturnal activity levels- with birds becoming more active as spring progresses into summer, dipping slightly during the nesting and incubation period and then rising as chicks fledge and leave the nest. These data are helpful for breeding programmes, monitoring the seasonal changes in animals as potential predictors of when reproductive behaviours may occur.

These data are also useful to those studying wild flamingos too, as if we know the times of the day that flamingos like to forage or rest, or where they prefer to gather in larger number, so we can help maintain or create such spaces within their wild habitats, away from disturbances to encourage birds to settle and breed, or to forage at times of the day most suitable for them. With four of the six species of flamingo having a level of conservation concern from the IUCN all information on their behavioural ecology can be useful to the conservation of future populations.

 

About the Author:

Dr. Paul Rose is a zoologist whose interests lie in behavioural ecology, ornithology and animal welfare. Paul has previously researched the relevance and importance of social networks in captive species, and the associated implications for zoo animal husbandry and welfare. He now researchers enclosure usage and breeding behaviour of captive flamingos to help further evidence base the husbandry techniques used for them.

“I would be interested to hear from anyone working in the zoo industries who is working with flamingos, or giraffes or wildfowl, as well as from those researchers who are also investigating similar questions / areas of zoo animal behaviour and husbandry across taxa. Please do get in touch if you’re interested in a collaboration.”

To find about more about Paul’s project click here

You can find Paul on:

Twitter

ResearchGate

LinkedIn

#ExeterMarine is an interdisciplinary group of marine related researchers with capabilities across the scientific, medical, engineering, humanities and social science fields. If you are interested in working with our researchers or students, contact Michael Hanley or visit our website!

Tracking Seabirds to Inform Conservation Measures At Sea

Author: Dr Nicola Weber

 

Having studied and worked in biodiversity conservation, with a marine focus, I have had the opportunity to work with a number of marine megafauna species, but it wasn’t until a move to Ascension Island (to work with sea turtles) that I forayed into the world of seabird ecology. Seabirds are known to be sentinels of the sea with a number of studies demonstrating how they can be used as indicators of the “health” of the marine environment. While seabirds nest on land, they largely find all of their food at sea, so any changes in the availability of their food resources can have a significant impact on their health and reproductive success.

As with many marine species, advances in technology have made it possible to study the largely unseen journeys and behaviours of seabirds at sea using increasingly small tracking devices that are normally attached the feathers of the bird. These devices then either need to be retrieved to download the data or can transmit it using satellite technology. During my time working on Ascension Island we attached tracking devices to a number of seabird species including the endemic frigatebird, the masked booby, sooty terns and yellow-billed tropicbirds. These projects involved many people including supervisors at the University of Exeter who conceived ideas and secured funding, experienced colleagues at the RSPB who helped with study design, deployment of devices and interpretation of data, and of course those working on the ground at the Ascension Island Government Conservation & Fisheries Department who know the area and the birds better than anybody else. Expeditions to tag seabirds, in particular on the offshore islet, Boatswainbird Island, that the local boat drivers skilfully got us on to, remain a highlight of my 5 years on Ascension Island.

 

 

Over the last 20 years, researchers have equipped over 100 species of seabirds with tracking devices to follow their movements at sea. As such studies become increasingly common, a wealth of information is being collected and many of these data have been contributed to the BirdLife Seabird Tracking Database and can be used for conservation planning or research, for example by identifying areas at sea that are important foraging grounds and hence may benefit from protective measures being put in place. It is only in this collaborative way that we can carry out holistic research projects to gain real insights into marine ecology and conservation at a more global scale.

In a new study published this week in the journal Marine Policy, researchers from RSPB and BirdLife International summarised the tracking data of 52 species from 10 families across the Atlantic Ocean (including those from the Ascension Island birds) to highlight the differences in the spatial scale of their movements during the breeding season. This summary, based on more than 12,000 foraging trips from over 5000 breeding birds, highlights the enormous differences between seabird families: while cormorants and shags often only travel 5-10 km out to sea, albatrosses, petrels, and frigatebirds routinely travel more than 200 km to find food during the breeding season. As there is a variety of options to protect seabirds at sea, it is thus important for policy makers and conservation practitioners to understand which approach is most suitable for which species based on their behavioural ecology. For example, birds that travel very far and exploit vast areas at sea may require conservation measures at a much larger scale than birds that travel only a short distance and remain in a smaller area.

 

 

This study highlights one of the aspects of academic research that I find the most interesting and rewarding – the collection of reliable data that can be used to inform management decisions and lead to tangible conservation actions being implemented, through the collaborative efforts of many people and organisations.

Please see the paper for full acknowledgements of people, organisations and funding bodies.

 

Dr. Nicola Weber 

(http://biosciences.exeter.ac.uk/staff/index.php?web_id=Nicola_Weber)

You can get in touch with Nicola through:

Twitter

ResearchGate

LinkedIn

 

 

#ExeterMarine is an interdisciplinary group of marine related researchers with capabilities across the scientific, medical, engineering, humanities and social science fields. If you are interested in working with our researchers or students, contact Michael Hanley or visit our website!

 

Scientists at Sea (Episode 1): Do crabs have ears? with Emily Carter

 

 

Show notes

 

Emily Carter – @E_E_Carter

How does noise pollution impact one of our coastal favourites? Ethan and Molly talk to Masters by Research student Emily Carter about her current work which investigates how the presence of ship noise affects the rate of colour change in shore crabs.

 

Other behaviours that don’t rely on noise at all can be quite drastically affected by noise pollution

Useful links from this episode:

Fiddler crab

Selfish herd hypothesis

Shore crabs

Crabs hearing noise

Gylly beach

Penryn Campus

Steve Simpson, Matthew Wale, Andrew Radford

Martin Steven’s Group/Sensory Ecology

 

 

 

 

#ExeterMarine is an interdisciplinary group of marine related researchers with capabilities across the scientific, medical, engineering, humanities and social science fields. If you are interested in working with our researchers or students, contact Michael Hanley or visit our website!

 

 

 

 

 

 

 

My #ExeterMarine MSc: Skates on thin ice: a phylogenetic study of vulnerable elasmobranchs

Author – Maisie Jeffreys, MSc Student – Molecular Ecology and Evolution group

Elasmobranchs (sharks, skates and rays) are more vulnerable to extinction than any other vertebrate group, meaning their protection is more important than ever. However, confusion remains surrounding the taxonomy of many species- making conservation difficult. Hence, more research needs to be done to answer taxonomic questions that still surround these endangered species.  

Elasmobranchs are some of the most fascinating creatures of the underwater world. Currently, there are at least 1,118  extant species of sharks, skates, and rays found throughout all corners of the globe: from depths of up to 4,000m in the deep sea and the icy waters of the Arctic, to shallower habitats in estuaries and freshwater lakes. Indeed, this group of cartilaginous fish can be found in just about every aquatic ecosystem on the planet, where they play vital roles in maintaining ecosystem balance.

Unfortunately, elasmobranchs are a group at high risk of extinction; due to habitat destruction, overfishing, and being caught as bycatch, an estimated 25% of species are thought to be threatened worldwide. The impact of elasmobranch decline is poorly understood, but given their important roles in aquatic ecosystems, the consequences are likely to be far-reaching.

Of all the elasmobranchs, the batoids (skates and rays) are the most vulnerable, with around 20% now threatened with extinction. Despite this, effective conservation of batoid fish has been hindered by a lack of accurate scientific data; many species are now listed as ‘data deficient’ on the IUCN red list, making establishing accurate conservation methods difficult.

This lack of data can be partially attributed to the large degree of morphological and ecological similarities among living orders of skates and rays. These similarities cause high amounts of cryptic speciation (animals that look alike but are genetically distinct), which results in taxonomic confusion and unstable nomenclature.

A classic example of cryptic speciation can be found in the Manta rays. Currently, there are two species of Manta ray; the larger species, Manta birostris, can grow up to 7 m in width, while the smaller, Manta alfredi, reaches 5.5 m. However, these were thought to represent just one species until 2009, due to their morphological similarities. This discovery has been vital in the conservation of mantas, particularly as it has allowed the clarification of the two species’ ranges. Since M. birostris is thought to migrate across open oceans, while M. alfredi tends to be resident and coastal, conservation efforts have now been targeted accordingly.

My Masters by Research focusses on resolving taxonomic questions that still surround several other species of endangered rays and skates, including the ‘common skate’ complex (Dipturus cf. flossada and Dipturus cf. intermedia), the Norwegian skate (Dipturus nidarosiensis), the longnose skate (Dipturus oxyrinchus), the thornback ray (Raja clavata) and the Madeiran skate (Raja maderensis). In order to answer these questions, I will be using restriction-site associated DNA sequencing (nextRAD) and mitochondrial DNA (mtDNA) sequencing to build phylogenetic trees for analysis. This work could potentially lead to the discovery of new species of endangered skate and has important conservation implications for batoid fish.

This project, supervised by Dr Andrew Griffiths and Dr Jamie Stevens, forms just one part of a host of exciting work being done by the Molecular Ecology and Evolution group (MEEG) here at Exeter University. Several other marine projects are currently underway, including research into the population genetic variation of brown trout (Salmo trutta) and Atlantic salmon (Salmo salar), and genetic connectivity in tropical corals and temperate invertebrate systems.

#ExeterMarine is an interdisciplinary group of marine related researchers with capabilities across the scientific, medical, engineering, humanities and social science fields. If you are interested in working with our researchers or students, contact Michael Hanley or visit our website!

 

My #ExeterMarine PhD: Social learning in whales and dolphins: implications for their conservation

Author – Philippa Brakes  (@PBrakes)

Whales perform some of the longest migrations on earth. Many live in close family groups, some sing, feed cooperatively, transmit innovations, share the care of their offspring and are even vital ecosystems engineers. They are the stuff of legend and the cornerstone of many marine eco-tourism businesses around the world. Yet despite the size of these charismatic megafauna, both in life and in our imaginations, they remain somehow enigmatic: the details of their lives are challenging for us to grasp. Nevertheless, through long-term studies, we are starting to unravel some of the mysteries and these scientific insights also necessitate a re-evaluation of how best to conserve these giants of the deep.

Behaviour matters. One key issue for the conservation of whales – and likely many other taxa – is social learning. There is growing evidence that many species of whales learn some important behaviours from their elders and sometimes their peers. Evidence for social learning in whales is found in all the main behavioural domains; from communication to foraging, migration to play. This is significant for conservation efforts. Understanding that behaviours from foraging strategies to migration routes may be socially transmitted, requires us to reflect on the types of resources whales need to survive and thrive in ever changing environments.

 

The emerging evidence in this field is also now beginning to influence conservation policy. The UN Convention on Migratory Species (CMS)  has been spearheading important work in this area. At a Conference of the Parties in the Philippines late last year, CMS committed to further examine the importance of social learning for the conservation of a range of migratory species. CMS also agreed a concerted action for the acoustic clans of eastern tropical Pacific sperm whales, which requires cooperation among the range states to gather more information about the social behaviours of these whales.

 

The better we understand social networks, the types of relationships individuals have, how they innovate and share new information and the roles that specific individuals may play within their social groups, the better equipped we will be for bespoke conservation solutions for animals that learn socially. A key area of importance to conservation will be determining how foraging strategies are socially transmitted. If information about a new technique for foraging on a specific resource is transmitted within a social group, these individuals may become specialist feeders on a particular prey type. Potentially, this has both conservation and evolutionary advantage, if this behaviour results in more efficient prey gathering or provides access to more abundant or better quality prey. However, such specialisation is not without risk. A significant decline in a certain prey type may present a challenge to the survival of some specialist feeders, unless of course they readily swap to other types of prey.

This ability to swap behaviour may be key. For example, bottlenose dolphins have the capacity to socially transmit new foraging strategies. But this species also exhibits sufficient behavioural plasticity to diversify to other prey types when their environment changes and certain prey become scarce. In contrast, killer whales, who are considered more conservative in their behaviour, generally adhere rigidly to their prey specialisations throughout their lifetime. There may be a tension between conservatism and plasticity, both within individual behaviour and across species, which highlights the complexity of conserving animals that learn socially.

 

But social learning is not the whole story; social structure, social role and even distribution of consistent individual difference (or personality) may also have an influence on the trajectory of populations. To examine this further WDC (@WHALES_org) and #ExeterMarine (@ExeterMarine) are investigating a feeding innovation in humpback whales off Cape Cod in the U.S.A., with the kind help of amazing WDC North America interns. Here, as well as bubble net and lunge feeding, a group of humpback whales have learnt a unique feeding strategy called kick or lobtail feeding. These whales lift the tail fluke (or entire caudal peduncle) out of the water in order to strike the water hard with the tail fluke (at least once) to stun the sand lance. This is typically followed by the whales then corralling the stunned fish by blowing bubbles underwater and surfacing with a mouthful of seawater and fish, which is then strained through the baleen.

This foraging strategy is unique to the Gulf of Maine population of humpback whales.  Previous research has determined this behaviour has been socially transmitted between whales in this population for nearly three decades. WDC (@WHALES_org) and ExeterMarine (@ExeterMarine) are now exploring whether factors such as age or social position matter when learning these new foraging skills. Is success rate related to whom you learn from, or are some individuals more predisposed to try out new innovations? Do some whales perfect their technique more rapidly than others, does skill level increase over time? Or, are particular individual differences in feeding style consistent over a lifetime? Do some whales never quite get the hang of the optimal kick feeding style and does that influence their overall calorific intake, their reproductive success, or even their longevity?

Our research so far indicates that individual whales exhibit their own specific styles of kick feeding, the question is how and if these styles change over time. Another interesting discovery is that some whales in this group seem to be goal hangers! There may be a producer-scrounger system in operation among these whales, although how dynamic this situation is remains to be seen. Non-kicking ‘scroungers’ may be benefiting from feeding on the fish stunned by the kicking whales. This begs several questions. Does it pay sometimes to be a kicker (producer) and sometimes a scrounger? Or is this part of the process of learning this unique foraging strategy? Does scrounging behaviour vary with group size? Are there ecological constraints? Only by gathering data on how these individual whales feed will we gain a better understanding of how these systems work and what role consistent individual difference may play in the spread of social learning of particular foraging strategies.

We can look to other taxa for clues. For example, chimpanzees exhibit gender differences in learning, particularly in relation to attention to maternal techniques, which has been used to predict competence in learned behaviour at a later date. Understanding whether similar differences between males and females exist in humpback whales will enable a richer understanding of social transmission in these species.

One thing is certain: whale science has advanced considerably since the save the whale movement of the 70s and 80s. Contemporary efforts to conserve whales from human-induced rapid environmental change requires more sophisticated and strategic approaches to protecting populations, which in some cases includes defining and managing social units. Saving whales today requires us to rethink some traditional approaches for delineating populations and shine a light on some of the detail of their individual lives. Just as ecological and conservation thinking has evolved from the elementary description of basic food chains, towards grappling with the complexity of food webs, future conservation efforts will need to incorporate the many facets of the social, as well as ecological, aspects of the life histories of these leviathans.

 

#ExeterMarine is a interdisciplinary group of marine related researchers with capabilities across the scientific, medical, engineering, humanities and social science fields. If you are interested in working with our researchers or students, contact Michael Hanley or visit our website!

Exeter MSc Students Sharing Marine Science Widely

Prof Brendan Godley  teaches a MSc module on Marine Biodiversity and Conservation at the Centre for Ecology and Conservation on the University’s Penryn Campus. The students learn about a wide diversity of topics and undertake independent study on two major topics within their specific interests. These are assessed by a dissertation and an oral presentation to their peers, respectively. This year, the tutor challenged his students to go a stage further and produce an infographic to communicate the message of their oral presentation to a wide audience that could then be shared on Twitter or other social media platforms. Brendan wrote;

Communicating science, especially conservation science, to a wide audience is a key skill we all need to work on. This was my initial reasoning for setting the task. I think. however, that the exercise really challenged the students to distil and clarify their key take-home messages in advance of giving their talks. They achieved both of these aims with some aplomb and were widely complimented on their work.”

 

The module sees a range of invited marine conservation practitioners sharing their sectoral experience with the students. Katrina Ryan of Mindfully Wired a consultancy which specialises in science communication was one of the invited experts this year and gave the students feedback on their infographics as part of her session. Katrina added;

“It’s wonderful to see vital communication skills being fostered as part of these students’ wider conservation science learning. Condensing such complex subject matters into compelling graphics is a real challenge, but the students did a superb job and, as a result, many had significant impact on social media”

Tweet from Hetty Upton

Click her to see a storify of the tweets, starting with the single most impactful by Hetty Upton.

 

#ExeterMarine is a interdisciplinary group of marine related researchers with capabilities across the scientific, medical, engineering, humanities and social science fields. If you are interested in working with our researchers or students, contact Michael Hanley or visit our website!

 

My #ExeterMarine PhD: Marine Turtles of Brazil

Author – Lili Colman (PhD Student) – Centre for Ecology and Conservation, Penryn Campus

From the moment I arrived at the University of Exeter to undertake my MSc in Conservation and Biodiversity, I quickly fell in love with the University, the Campus and Cornwall. Discovering all the cutting-edge research being carried out across the University of Exeter has been a definite highlight for me. The opportunity to participate in the Africa field course was one of the most amazing experiences of my life and one I will always cherish, having helped me build a practical understanding of large-scale conservation issues. My MSc research project centred on analysing 30 years of mark-and-recapture data from juvenile green turtles on an isolated tropical archipelago in Brazil, under the supervision of Prof Brendan GodleyThis published work contributes important insights regarding demographic parameters and population trends for this species.

Lili_Kenya
Meeting the Maasai in Kenya

 

Upon my return to Brazil, and whilst working as an environmental consultant there, I applied for a PhD at Exeter to work with TAMAR (the Brazilian Sea Turtle Conservation Programme). This on-going conservation project illustrates a powerful example of how marine turtles and coastal communities can co-exist in an ever-changing world. Despite a history of over-exploitation, the five different species of marine turtles that nest in Brazil are now fully protected by law. And as a result, recent years have shown very promising signs of population recovery. Perhaps most notably, a major part of this success can be attributed to the active involvement of the surrounding coastal communities in the conservation work. What once started in the direct employment of former egg poachers, now involves a wide range of activities to encourage environmental awareness in the area. This includes environmental campaigns, alongside the support of alternative, sustainable economic opportunities for the communities living near the nesting beaches.

Tamar

Local kids talking turtle in Bahia, Brazil (Banco de imagens Projeto TAMAR)

My PhD research focuses on the highly migratory leatherback sea turtle (Dermochelys coriacea). This species has its major nesting site deep in the southwestern Atlantic ocean in eastern Brazil, on the northern coast of Espirito Santo. Projeto TAMAR has been monitoring the area since 1983 and there are promising signs of population recovery for the species. However, with a small population size and restricted geographical distribution, alongside the emergence of new threats – coastal development, fisheries bycatch, climate change, marine and light pollution – the population continues to be of conservation concern.

(Henrique Filgueiras)
Lili records leatherback sea turtle nesting (Henrique Filgueiras)

As part of the Marine Turtle Research Group (MTRG) at the University of Exeter, we are using a variety of techniques to investigate this population’s ecology, trends and the main impacts they are facing. This research is being done in collaboration with TAMAR in Brazil and Ciência Sem Fronteiras , a scholarship programme from the Brazilian Government. The knowledge obtained in this study will be used to design better and more effective conservation strategies for this species. I was delighted that my PhD project was chosen to feature in one of the films to celebrate TAMAR’s 35th anniversary:

#ExeterMarine is a interdisciplinary group of marine related researchers with capabilities across the scientific, medical, engineering, humanities and social science fields. If you are interested in working with our researchers or students, contact Michael Hanley or visit our website!