Saturday, 24 June 2017

Fieldwork 2017 - the first 2 weeks!

Commentary by Sara Tavares



We’ve started our 2017 field season in Vestmannaeyjar and the first two weeks of fieldwork are completed! We’ve had our first Earthwatch team joining us and despite the periods of strong winds, rain and fog, we had some amazing sightings from the land station and encounters from the boat.

Adult male killer whales close to Heimaey. Photo by Sara Tavares.

Our land station is on Stórhöfði, a peninsula at the southern end of Heimaey which is the place of a meteorological station (officially the windiest place in Iceland!). From there, we can use using high-magnification binoculars to search for killer whales and other marine mammals and record their position using a theodolite. This will give us information on how groups of animals use the area over the season.

From the land station we saw killer whales, humpback whales, porpoises, potentially a beaked whale species (but it was not possible to confirm it), and pilot whales. And the observations of pilot whales could not have been more amazing! They appear in groups of hundreds and can be seen arriving from far away, in the horizon, since so many whales swimming so fast do a lot of splashing in the water!! And it’s incredible to see these large groups of whales arriving and the killer whales just moving away as the others come closer, eventually disappearing. The pilot whales are chasing the killer whales away! It was incredible to witness this from the land station.

Land station. Photo by Filipa Samarra.

Scanning for whales. Photo by Filipa Samarra.

We had awesome encounters from the boat, we saw many familiar killer whales (including a particular one with a distinct deformity in the spine, see our Facebook post here), minke whales, pilot whales and also an incredible sighting of a carcass of what looked like a shark. We could see the shark gills in the carcass on the sides of the head. It could have been a Basking shark but it was not possible to confirm the species due to the degradation of the carcass.

Killer whales travelling. Photo by Graeme Ellis.

Pilot whales coming close to the research boat. Photo by Graeme Ellis.

Shark carcass encountered floating on the water. Photo by Graeme Ellis.

From the boat we took photo-ID pictures and behavioural observations of the killer whales. And we were pooped on by gannets… a lot! It is very common to have countless gannets flying in circles above the boat.

These weeks were a very successful start of fieldwork. It was great to have such a fantastic Earthwatch team joining us in the field and it was wonderful to work with them all! We’ll have a second team joining us soon and we’ll keep you updated on new encounters and observations over the next couple of weeks!

Tuesday, 17 January 2017

The first detailed study on the social structure of Icelandic killer whales

by Sara Tavares

It was the 21st of July 2015 and we had been in the water for 2 hours observing a group of whales. We were nearing the end of our field season and had been observing this particular group of whales for the last days. The group included one adult male, 3 females/subadult males and 2 juveniles which had been travelling and feeding in close association. As the day drew to a close we returned home and wondered if we would see them again the next day. I was puzzled, since I remembered these whales from the winter season the previous year and I never saw them together. The next day we found some of the same whales but others had been replaced. The group was now composed of 2 adult males, 4 females/subadult males and 2 juveniles. Only 4 of the individuals were the same as in the first original group we had observed. To our surprise, the day after we saw the 2 missing whales from the first original group with completely different whales. What was going on here?…




Understanding the social life of killer whales requires several observations of the same individuals over time, so that patterns of association can be seen. This type of long-term data is essential to understand if whales form stable and coherent groups, and if there is a hierarchy in associations. We studied associations in the Icelandic killer whale population, a fish-eating population that seems to feed on herring, to investigate for the first time in detail what the social structure of this population might be like. Up to now, how killer whale populations are socially organised was thought to be determined solely by differences between feeding on fish and feeding on mammals.
For example, resident killer whales in the Pacific, that feed mainly on salmon, form clear family groups of individuals that associate very strongly (are always together) and their offspring stay with their mothers throughout their lifetime. These groups are called matrilines and generally all individuals within a matriline associate equally strongly. Different matrilines associate with each other for some periods of time in a hierarchical way - some associate more than others, creating a tree of associations. The mammal-eating population in the Pacific (also called transients or Bigg’s killer whales), which feeds mainly on seals, also has stable family groups but there is some dispersal of both females and males from their family groups that is not seen in the resident population. Associations between adult males are very rare and unstable in this population. The dispersal seen is needed to maintain smaller groups than the ones present in the resident population, which is optimal for feeding on seals. In our study of the Icelandic herring-eating population, curiously, we found striking differences from both mammal- and fish-eating populations in the Pacific. So what else might be shaping the social structure of killer whales worldwide?

Using photographs of 198 identified killer whales we measured their association values. We discovered that associations in the Icelandic population are not random but there are very few, very strong associations among individuals. Members of social groups were not always together and didn’t associate equally strongly, unlike what is seen in residents. On the other hand, like in residents but unlike transients, there was no dispersal of either sex from their groups. In this population there was no hierarchy of association where small groups of individuals associate preferentially with other groups – that is, not all individuals associate at similarly high levels within social groups and distinctly lower levels between social groups.

There is, in fact, large diversity in the groups formed. Some of the groups are simple with similar associations between individuals. However, the majority of groups formed have many different strengths of associations, that is, individuals associate differently with other members of the group, and some groups seem to be composed of more than one subgroup. Associations between whales can be constant, or temporary. But temporary associations were not between coherent, stable groups that associate together for some time, as in the Pacific residents. Instead, they seem to be between (sets of) individuals that associate casually but with preferences. For example, some individuals might prefer to associate in the summer but not in the winter, or in one year but not in others. So they might hang out with the same individuals but be apart for several seasons (and therefore have low association values).

One of the most interesting finds was that associations between individuals were not completely determined by their movement patterns. We know that the whales we see in Iceland have different movements; for example, some go to Scotland in the summer while others appear to stay in Icelandic waters year-round. We also know that some of these whales even have different feeding ecologies. In the Pacific the mammal-eating and the fish-eating populations seem to be socially isolated, but in Iceland we see whales with different movement and feeding habits forming groups. For example, the killer whales matched to Scotland, which feed on fish and seals, sometimes group with individuals seen in Iceland year-round, that appear to follow the herring stock.

Examples of close associations between individuals with different movement patterns, subgroups and groups: 
(a) IF-4, who travels between Iceland and Scotland, in close association with individual IS121, seen year-round in Iceland; (b) 997, another whale who travels between Iceland and Scotland, in close association with IS041, also seen year-round in Iceland.

Although our study shows that killer whales in Iceland don’t form stable, coherent family groups alike those of residents, it is possible that these do exist but are just not behaving exactly the same. So, although both residents and Icelandic killer whales feed on fish, they seem to present different association strategies.

To understand why, consider the differences between Pacific residents and Icelandic killer whales. To start with, they target different prey! Salmon and herring behave very differently and require very different feeding strategies that, in turn, shape the way each killer whale population catches its prey and, likely, the way they socially organize. For example, in Iceland the whales seem to use a group feeding strategy that requires coordination to successfully hunt herring. When herring schools are larger, the whales likely benefit from forming a larger group. We often observe whales in large aggregations in Iceland, concentrated in a relatively small area where there is a lot of herring. This creates lots of opportunities for associations with different individuals and, given the possible benefits for dealing with larger (and always changing size) herring schools, a more fluid social structure may be beneficial for these whales.

The fact that we have observed Icelandic killer whales on herring grounds revealed the fluidity in the social structure of this population, but it will require many more years of observation before we understand the full details of their social structure. Indeed, it is possible that more observations might reveal stable, coherent groups particularly at other times of the year when large aggregations are not as common. For now, we will continue using photo-identification to investigate all these questions over longer time periods and in more behavioural and environmental contexts. We are also using genetic data to learn about the relatedness between individuals that associate and have different movements. We hope to give you more exciting news of these studies soon!
Research paper:
A multilevel society of herring-eating killer whales indicates adaptation to prey characteristics
Sara B. Tavares; Filipa I.P. Samarra; Patrick J.O. Miller
Behavioral Ecology 2016;
doi: 10.1093/beheco/arw179

Wednesday, 3 August 2016

Fieldwork 2016 - the end! What a great season...

 Commentary by Julie Béesau and Marie Louis



Our 2016 summer fieldwork is now finished. We have packed all the equipment and left the beautiful archipelago of Vestmannaeyjar. We had a very successful data collection this season and a month full of good weather, great orca encounters and an amazing group of people! Team members Julie Béesau and Marie Louis share with us their thoughts about the season. 


Julie

It was a pleasure to come back to help again the Icelandic Orca’s team, now in the summer place in Vestmannaeyjar. I discovered this wonderful area that is completely different from the winter fieldwork, I cannot compare the two areas. It’s just so amazing to be on the boat with the amazing wild animal named orcas. I spent two weeks there to participate in the data collection, in particular photo-ID.
As always the team atmosphere was really great, everyone on the boat was so happy to be in this beautiful landscape with whales and try to collect as much data as possible.
We had some great encounter with orcas and we saw some breaching and socialisation like the “pink lamprey”… I would like to thank everyone for this wonderful two weeks spent there.

Happy killer whale around Vestmannaeyjar. Photo by Julie Béesau. 

Amazing sunset after our last day on the boat. Photo by Julie Béesau.


Marie

Fieldwork and staying in Vestmannaeyjar was amazing. We had really great weather during the last 8 days and could go out at sea every day. We saw lots of killer whales in large feeding aggregations. One of the highlights of the season was to see hundreds of killer whales swimming very fast away from the pilot whales! It was very impressive!
Thanks everyone for a great time!  And a special mention to our favourite friendly whale Cray-cray featured in the last blog post!

Spy-hopping killer whale. Photo by Marie Louis.

The A-team enjoying the last very sunny and warm survey day (yes this photo was taken in Iceland!). Photo by Marie Louis.

Wednesday, 27 July 2016

Fieldwork 2016 - on the last week already!

 Commentary by Gary Haskins

Gary Haskins joined the Icelandic Orca project fieldwork this season as a skipper. This blog post is about his experience over the first 3 weeks with us.


We have been testing out the feasibility of utilising a land based crew to monitor and track orca movements using a theodolite. This system allows us to record the positions and movements of whales, boats, tidal flows/upwellings, etc., on map in real time. This is cool as firstly the land based team can direct boat teams on the location of whales, but also you get large scale movement and behavioural data that can be then related to lots of environmental factors or even boats in the area. This gets even cooler when you place a listening device, moored at sea visible from the land station so that behavioural activity can then be monitored in conjunction with ‘listening in’ on the associated vocalisations a’ la the NSA. Unlike the NSA however, we welcome whistle blowing.

This is all good in theory (and in practice eventually) but theodolites are fickle beasts, otherwise known as pieces of precision equipment. They have to be set up carefully and once set up, they must not be knocked. They become difficult to use at rock concerts, and I imagine they are a right pain in Space, but of more relevance they are a bit iffy in windy places. It turns out that our land observation point, Stórhöfði, is the windiest place in Iceland. Literally. (The actual meaning of literally, not the silly new meaning, where literally has literally become the antithesis of itself).

OMG! Jen was so happy to be collecting data she literally died.

In short the theodolite has to be levelled and any movement by a tiny margin will give false or no readings. Therefore wind can hinder the set up. But, we went from taking two patience sapping hours to being able to do it effectively and accurately in 10 minutes. We successfully tracked orca and collected some nice data on minke presence and movements for our undergrad student, Jenifer Stollery. We even recorded a sneaky anomalously pigmented (white) harbour porpoise calf.

A porpoise is in this picture somewhere. Photo by Jen Stollery.

Other than that I have been skippering the boat, helping out with Photo-ID and bit of acoustics and anywhere that I can try and lend a hand. Our main goal this week has been to acquire biopsy samples from orca using an ARTS system. The ARTS fires a dart that takes a small sample from the whale (its harmless) and allow all sorts of information to be determined; diet, movements, sex, relatedness, pollutant load. Again, great sounding in theory but in practice it can be pretty tricky to get close enough to these animals. According to Craig Matkin, they act like ‘offshores’. That basically means they are boat shy and have a circle of trust, of about 25 or more meters. We can biopsy up to about 18 m so gaining access is a case of softly, softly catchee monkey. But man, those last few moments, as we edge ever closer, timing our gentle arrival to the last surface of our target animal before it dives…..you could cut the air with a theodolite.

Miguel with the ARTS system, as we enter the circle of trust.

Celebrating a successful biopsy, Miguel claims all the credit and won't share the sweets.

As well as boat shy, twice now I have seen these orca porpoise at high speed away from incoming pilot whales. Admittedly there were lots of pilot whales charging in like madmen but there were perhaps over one hundred orca. In addition, a local fishermen was telling us about how the whales he sees from his boat always flee when the porpoise turn up. He insists its porpoise displacing them. Orca – you used to be cool man, what happened?

Scary pilot whales apparently.

N.B. I say they are wary and boat shy, and they are. All exempt our new favourite whale, IS423 – affectionately named by Miguel as Richie Cray-Cray. Whilst the others are playing hard to get, IS423 approaches the boat and swims in our wake, less than a metre from us, seemingly attracted to the bubbles produced by our engine. He is now too close to biopsy, obviously.

Thanks to all for having me as part of the team! It is greatly appreciated.

Video of IS423 (by Miguel Neves).



Tuesday, 19 July 2016

Fieldwork 2016 - the first 2 weeks!


Commentary by Marie Louis

Marie Louis is a post-doctoral fellow at the University of St Andrews joining the Icelandic Orca project fieldwork this season. This blog post is about her experience over the first 2 weeks with us.

I am helping with field data collection on killer whales in Vestmannayejar since two weeks. It has been a fantastic and interesting experience so far. Sara and Filipa explained us during the first couple of days how the material was working and how the data should be collected. 

On the boat, I am in charge of taking photo-identification data. Sara showed me during the first two trips how the photo-ID data is collected in particular for social structure analyses. The challenging but also exciting part is to get eye patches’ photos of the calves as they are fast and often stay behind their mother. It greatly helps for their identification as their saddle patch is usually faint. 

Adult male dorsal fin and saddle patch. Photo by Marie Louis.
Female and juvenile. Photo by Marie Louis.

Female, calf and juveniles. Photo by Marie Louis.
We had really great encounters with the killer whales and good weather conditions. We are re-sighting part of the same whales trip after trip, sometimes with different associates. Some of the whales (as illustrated by the below photos of the male with the floppy fin and the female with a big notch on the dorsal fin) are easy to recognize in the field. During the last trip, several groups of whales were feeding and surrounded by lots of diving gannets. There was also a humpback whale in the middle of the groups of killer whales. We sampled herring from these feeding events; Filipa will use them for stable isotopes analyses to better understand the feeding ecology of the killer whales. 

Humpback whale. Photo by Marie Louis.

Adult male with a floppy fin. Photo by Marie Louis.

An easily recognizable female with a big nick (IS035). Photo by Marie Louis.

It was also very interesting to see other parts of the data collection: acoustic recordings and behavioral sampling, and tracking data collection from land using a theodolite. I am very glad to be here, the Vestmannayejar is a very beautiful archipelago and an amazing field site. It is also a paradise for seabirds and puffins-fans!  Every evening we rotate to cook a nice meal for everyone and learned new recipes including tasty vegan cakes. We have been stuck on land due to a storm yesterday but tomorrow’s forecast is looking good. I am looking forward to see what the next two weeks will bring!

Juvenile killer whale. Photo by Marie Louis.

Gannet rock in Vestmannaeyjar. Photo by Marie Louis.

Puffin. Photo by Marie Louis.

The view from the volcano that erupted in 1973. Photo by Marie Louis.

Sunday, 3 July 2016

And we are starting!

We are starting our 2016 fieldwork in Vestmannaeyjar of 1 month… This fieldwork will be a collaboration between the Marine Research Institute and the University of Cumbria. This last couple of days have been full of team members arriving and setting up equipment! We still have some work to do on land before we get on the boat… But just yesterday some killer whales were sighted close to the main island Heimaey where we are staying! So things look promising here and we are very excited to start!

This season we will be collecting photo-ID data, behavioural observations, sampling feeding events, biopsy samples, acoustic recordings and land-based observations. With this we investigate the distribution and movements, social and acoustic behaviour and foraging ecology of the Icelandic killer whale population.

We’ll keep you posted on the progress of the fieldwork through the next weeks! Here are some pictures from these first days from Marie Louis, who's joining us this year.

The view from Heimaey. Photo by Marie Louis.

Minke whale seen from land. Photo by Marie Louis.

Killer whales seen from land. Photo by Marie Louis.

Killer whales seen from land. Photo by Marie Louis.

Team members scouting for whales! Photo by Marie Louis. 

The midnight sun in Heimaye. Photo by Marie Louis.


Killer whales seen from land. Photo by Marie Louis.

Puffin. Photo by Marie Louis.




Tuesday, 14 June 2016

DNA can say so much...

Commentary by Sara Tavares

The amazing work done for more than 20 years in British Columbia, photographing and identifying (all) killer whales, gave us unprecedented knowledge about this species. The detailed photographic dataset created in British Columbia is invaluable for the conservation and monitoring of the local populations.

But sometimes photographic identification is not enough and other kinds of information from the individuals becomes important, such as its specific genetic "fingerprint" - DNA.

This blog post by Dr. Carla Crossman, molecular and marine biologist with the Vancouver Aquarium Marine Science Centre’s Coastal Ocean Research Institute, is a great example of how invaluable genetics studies are when working with wild populations. Last April, 2 dead individuals washed out in British Columbia in a state of decomposition that did not permit identification based on appearance. But using existent knowledge of the genetic variation across populations, the Vancouver Aquarium Marine Science Centre’s Coastal Ocean Research Institute discovered to which population the individuals belonged to by their genetic code. Working long hours to get this information as soon as possible, the molecular biologists in the Institutes’ Conservation Genetics Lab were able to tell that both whales belonged to the fish-eating resident population and more specifically to the southern community! Amazing, right? This was possible due to previous studies by Dr. Lance Barrett-Lennard, currently senior marine mammal scientist at the Vancouver Aquarium Marine Science Centre’s Coastal Ocean Research Institute, that discovered which variations in the genetic code distinguished the killer whale populations.


3 males traveling together. Are they from the same family and therefore genetically related? Uncovering this is one of the goals of the Icelandic Orca project.


We are currently working on building up this kind of genetic knowledge on the Icelandic killer whale population to help us monitor the status of the population. One of the goals of our project is to map the genetic relatedness among individuals and understand the genetic variability within the population. It will be some years until we uncovered all this but during the last 2 years we made great progress collecting small biopsy samples of skin from photo-identified individuals. Lately, we have been trying to find the best genetic markers to use on this population (because the variations in the genetic code are not the same among populations) so that we can start uncovering this vital information about the animals.

But, as Carla Crossman so well shows on her blog post, genetic analysis can be a slow process... Even just extracting DNA from a small piece of skin from a single individual whales takes several days! And extracting DNA is just the very first step! Then you need to test different genetic markers, optimise protocols and only once all that is complete can you start going through all the small skin biopsies to start gathering information from different individuals. So it can usually be many months until this type of analysis is complete. We will keep you posted about new developments on the very exciting genetic studies being conducted!