Monday, 28 August 2017

Fieldwork 2017 – that’s all folks!

Commentary by Sara Tavares



Juvenile killer whale. Photo by Sara Tavares.

And this year’s fieldwork is now finished. These were some full 3 months!! We have now packed everything and left the beautiful island of Heimaey. But this was not an easy trip. The bad weather (strong winds that lead to high swell!) made it more complicated than it needed to be, with canceled ferry trips to mainland Iceland and then a ferry trip that took 3 hours (instead of the normal 30 minutes!)... But we eventually made it!

Packed car!

Before the bad weather hit the archipelago, we still had an awesome encounter with killer whales during the last week. These whales were travelling almost non-stop, they had somewhere to go! 3 of the juveniles kept coming close to the research boat, it looked like that they were playing with the bobbles that the engine was making… Very cool to see, but the driver had to be extra-focused since we had to navigate the boat with even more caution than usual, because they were coming so close!


These killer whales were travelling fast, where were they going? Photo by Sara Tavares.

Adult male killer whale travelling. Photo by Sara Tavares.

The Icelandic Orca project will be back next year, and all new fieldwork adventures will be reported here on the blog! Takk fyrir Iceland! Takk fyrir Vestmannaeyjar!

Tuesday, 22 August 2017

Fieldwork 2017 - Minkes don’t eat chips

Commentary by Miguel Neves

Miguel Neves has been a part of the Icelandic Orca project fieldwork for the past 5 years. This blog post is about his experience over these last 2 weeks of August 2017.

Blue whales close to Heimaey. Photo by Filipa Samarra.

The last Earthwatch team of the season (team 5) has just left. After our one week forced break in the beginning of August because of the Þjóðhátíð1, it was a relief to see the whales were still around. This was the first time the fieldwork ran in August, and we were happy to learn that killer whales could still be found here this time of the year. But they weren’t the only thing we found. On one day we spotted blue whales from the land station and followed them on the boat to take pictures to share with researchers studying this species (did you know that a blue whale’s tongue alone can weigh as much as an elephant, and their hearts as much as a car?); on another day we worked with the killer whales so close to shore you could hear the blows from the land station, in Stórhöfði!

Glacier behind Suðurey. Photo by Sara Tavares.

The day after that, the sea seemed dead. No whales were spotted from the land station. Even so the sea was so flat we decided to go out on the boat to scout further offshore. And boy were we happy we did it. Behind the islands, in the land station’s blind spot, we saw an aggregation of minke whales, and counted over 11! Minkes feed on a wide range of prey, including small schooling fish, such as herring, capelin and sand eel, demersal fish, like cod and haddock and yes, you guessed it, not chips. But they do feed on krill! And we got to see those red patches in the sea that are made up of thousands and thousands of minuscule crustaceans, and the surface of the water seemed to bubble when they swam. This is the stuff documentaries are made of.

One of the minkes of the aggregation. Photo by Sara Tavares.

Red-necked phalaropes and a minke in the background. Photo by Sara Tavares.

video
Video by Miguel Neves.

1Þjóðhátíð (from Wikipedia; English: The National Festival) is an annual outdoor festival held in Vestmannaeyjar, Iceland […]. Locals and guests gather in Herjólfsdalur valley on the island of Heimaey for four days of various events. […] Þjóðhátíð was first held in 1874 when islanders were prevented by bad weather from attending the celebration on the Icelandic mainland of the millennium of Icelandic settlement.

Saturday, 19 August 2017

Fieldwork 2017 - lots of work in July!

Commentary by Sara Tavares


Uff!! We’ve been busy… We’ve had some full weeks at the end of July! Work with Earthwatch team 4 started slow, with some very bad weather (mostly strong winds) not allowing us go out on the boat or do land station surveys. However, after a few days, the weather changed completely and we were working non-stop! 

We had days with lots of sightings, one day we saw 4 different species: minkes, harbour porpoises, pilot whales and killer whales! Check out this video (by Miguel Neves) of the team working on the boat observing feeding killer whales:

video

We had a 1 week break during the first week of August and now we are back to work, with more news to come soon!

Monday, 24 July 2017

Fieldwork 2017 - the first 2 weeks of July!

 Commentary by Tom Bean

Tom Bean joined the Icelandic Orca project fieldwork this season as a skipper. This blog post is about his experience over these last 2 weeks with us.


Data collection with Earthwatch team 3 started in haste with particularly good weather, and clear views of the glacier – the calm before the storm! We found whales right away and were treated to some unique experiences. Namely, four whales had moved closer to the land station, and both the boat and land teams were treated to observing killer whales in and around the cave under Suðurey.

Killer whales inside a cave! Photo by Sara Tavares.

On the same day we managed to collect two herring samples from a feeding event.

Measuring the size of the prey fish collected during a feeding event. Photo by Filipa Samarra.

The days following this became more difficult to conduct boat surveys with limited weather windows. We rose from our rest between 5 and 6 on one morning, attempting to find a break in the weather of just a few hours. Unfortunately, the weather was not as predicted and we were not so lucky. Increased effort was focused upon the land station with more pairs of eyes and binoculars!

Land station seen from the boat (can you see those little dots at the top??!!). Photo by Sara Tavares.

Outings to the land station always bring excitement – foremost for the diversity of wildlife sightings in general, but also accounting for a stunning landscape, weather and sheep behaviour! It’s edge of the seat perseverance working in such a remote and alien environment. Personally, I often strain my eyes with my keenness to find something in an eight-hour survey period. Stopping to think about our location really drives home how privileged we are to be working here. Let me orientate you - behind us to the northeast there’s a huge glacier, Eyjafjallajökull (remember that one that erupted in 2010, cancelling all the planes?). It’s super stunning on a rare clear day. In front, to the southeast, is a myriad of islands, stacks and underwater volcanic mounds – lined up but spaced out in near precision – a physical documentation of eruptions through time (a bit like Galápagos). Not forgetting Surtsey, the furthest island from us, the extent of our survey area and one of the newest islands in the world, created by a sudden upwelling of magma in the 1960s.

Eyjafjallajökull visible at the distance. Photo by Sara Tavares.

If that wasn’t enough, we’re perched on the edge of an inhabited active volcanic island in an archipelago south of Iceland, peering over a one hundred metre sheer cliff, surrounded by 800,000 pairs of Atlantic puffins – the biggest colony in the world. Again, adding to the awe, we’re surrounded daily by stunning birdlife – ravens, great skuas, fulmars and snipes to name a few. Ravens are one of my favourites to watch, just for their sheer size, perceptual intelligence and noisy attitudes. Although male snipes put up a good fight in the noisiness contest, drumming their tail feathers in courtship displays.

Fulmars being fulmars... Photo by Sara Tavares.

OK, so we’ve walked the distance from the car to our station, seen some birds in their summer breeding rhythm (before the days grow short once more), but now the real work begins. We’re here to find whales! Our priority is to locate a group of animals for the boat team to gather some discrete focal data. Ideally, a small feeding group where every individual is photographed followed by a prey sample collection and a tissue biopsy – our main focus here is foraging ecology. So while one person commences the search, the remainder of our team sets up the theodolite, laptop and tent, simultaneously ready to record a sighting or shelter from any weather thrown at us. Our purpose is twofold: finding whales and reporting on the weather across the archipelago. As such, the boat and land station teams are in frequent contact and our role is critical to the success of the data collected from the boat. Intermittently we’re joined by our friends – the sheep. Big eyed, hungry and shaggy. Their fleeces are messy, and I mean hanging off their backs!

A killer whale checking us out! Photo by Sara Tavares.

During our land-based effort, it was a pleasure to speak with and educate tourists and school groups from around Europe and North America about our conservation and research work, and for some people to see their very first whales! It reminds me of my first wild cetacean encounters – the awe and wonder of a short snapshot in the lives of large and independent animals going about their business to feed and survive. No regard for the shopping centres, pop culture, advertising and fast-paced lives so many of us are now accustomed.

Thursday, 6 July 2017

Fieldwork 2017 - June completed! What will July bring?

Commentary by Sara Tavares

Two more weeks have past and we couldn’t have been luckier with the weather! We had the second Earthwatch team joining us over these weeks and we went out on the boat and worked in the land station almost every day.

Adult male killer whale travelling. Photo by Filipa Samarra.

We started this second study period very apprehensive, since we had read on the news about the NATO (North Atlantic Treaty Organization) exercise just South of Vestmannaeyjar running from the 23rd of June until today. We had no idea what this exercise involved but wondered if something could have an impact on the killer whales and make them move away from Vestmannaeyjar. So on the 26th of June we went out on the boat, and we searched for whales the whole morning around Heimaey. Nothing… No killer whales or any other marine mammal. The land station also looked for whales the whole morning and 3 different people saw a minke whale only once (!) and at different times… And never saw it again. They started calling it a ghost whale… Was it even real?

It seemed like a “dead sea” to us. And we were wondering: “Could this be connected to the NATO exercise? Did all the whales move away from here?”… But not giving up, in the afternoon we opted for a different route and looked for whales over the Northwest, further away from Heimaey where the land station only has partial view of the North of Vestmannaeyjar. And there they were!!! Killer whales everywhere! They were still here and it was around that area that they spent most time of these 2 weeks. We had amazing observations of feeding events in these area! We even had spy-hops and breaching whales at some point.

Humpback whale sighted from the boat. Photo by Filipa Samarra.

Adult male killer whale. Photo by Sara Tavares. 

The land station could follow the movement of these whales in the area and also saw other marine mammals from there, including pilot whales in the South of Heimaey. These were some amazing two weeks with lots of data collected. It shows that we can never get discouraged if we don’t find whales. Also, it is important to know that the whales are not in a specific area, so that we can learn how they use this herring spawning ground. As many researchers say: no data is good data!
We are looking forward to meet the third Earthwatch team and to continue data collection over the next two weeks. We can’t wait to see what these amazing killer whales will do next!

Kittiwake feeding near killer whales. Photo by Sara Tavares. 
Killer whale breaching. Photo by Sara Tavares.

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