The Northern Bottlenose Whale

We are wrapping this year with a lesser-known, but very well studied ziphiid, or beaked whale, the northern bottlenose whale (Hyperoodon ampullatus). The northern bottlenose whale is the largest member of the beaked family found in the North Atlantic Ocean. They have a bottle-shaped beak and a hooked dorsal fin, hence the “bottlenose” in their common name. They have bulbous melons, which are their most prominent attribute. In this post, we will explore these phenomenal creatures, in collaboration with Whale Wise!

Head-butting news

Evolutionary impacts differ between two exploited populations of northern  bottlenose whale (Hyperoodon ampullatus) - Feyrer - 2019 - Ecology and  Evolution - Wiley Online Library
Male Northern bottlenose whale with its prominent melon – Credit: Laura Joan Feyrer

The males’ melons appear quite flat on some old bulls. Scientists have been trying to come up with an explanation for on why their melons flatten with age. Scientists also discovered the bone density behind the melon is higher in old males. Turns out, adult males spend a good portion of their time ‘head-butting’ each other like bulls! This behavior maybe a type of male-on-male aggression. Males head-butt each other so much that their melons flatten with time.

While there is still limited evidence on head-butting, males-on-male aggression is not uncommon in beaked whales. In other beaked whale species, modified teeth that look like tusks are used in competitive male-male behaviors. This typically leaves a lot of body scarring. Although northern bottlenose whales do not show a lot of scars, they seem to let off steam by bumping into each other, literally.

Whale Wise observed that the heads of adult males look quite wrinkled, unlike females, as if they have been battered a lot! – Credit: Whale Wise

Sensitive Deep Divers

Typically eclipsed by their cousins, the Cuvier’s beaked whale, northern bottlenose whales are deep divers as well! Northern bottlenose whales’ deepest dive was recorded at 2339 m (94 minutes)! Generally, northern bottlenose whales are one of the most sensitive cetaceans to sonar and usually try to escape. They, like their other beaked whale counterparts, typically feed on deep-sea squid, fish (e.g., herring), shrimp, sea cucumbers, and sea stars.

Whaling history

Northern bottlenose whales are known to be one of the most curious beaked whales. They are attracted to stationary vessels and are highly reliant on their social bonds. In the 1850s, fishers discovered that northern bottlenose whales had a large amount of spermaceti (a waxy substance used for oil lamps, candles, and lubricants). Thus, the fishermen exploited the northern bottlenose whales’ curious nature. By the 1970s, over 80,000 individuals had been hunted, making them the only commercially hunted beaked whales. Scientists have since reported evidence of population recovery, but only in some parts of their original range. Their only current exploitation comes from the Faroe Islands whaling industry.

Northern bottlenose whale breaching in Skjálfandi Bay, 2018 – Credit: Etienne Ménétrey

The famous Thames Whale

The River Thames is the longest river in England. In 2006, an unexpected guest made its way up the river. The ‘River Thames Whale’ was a young female northern bottlenose whale, nicknamed Willy. She got lost and beached herself several times as the tide went out.

On the third day of her visit, the British Divers Marine Life Rescue (BDMLR) decided they needed to intervene. Along with the Port of London Authority and the Metropolitan Police, they decided to intentionally beach her so they could move her and give her a medical examination. Two hours after her capture, she was lifted onto a barge by crane. By 5 pm, she was still out of the water and her health was drastically decreasing. Sadly, at 7:08 pm, she died due to convulsions.

The Thames whale, Willy – Credit: Brett Lewis/BDMLR

We hope you learned a thing or two about northern bottle nose whales! We would like to thank Whale Wise for sharing their knowledge on northern bottlenose whales with us. Keep reading the second part of our article to learn more about Whale Wise, founded by Tom and Alyssa, two early-career researchers.

Whale Wise and northern bottlenose whales, by Tom and Alyssa

2018 Iceland: A Hopeful Beginning

Whale Wise started in 2018, with our first field season that summer in Skjálfandi Bay, North Iceland. Húsavík, on the eastern side of the bay, is known as the ‘Whale Watching Capital of Europe’ and home to four whale-watching companies. Our sole aim was to study humpback and blue whales‘ response to whale-watching vessels, collecting behavioral and physiological data. We collaborated with the University of Iceland’s Research Center in Húsavík, who guided our research plan and provided accommodation and equipment.

Alyssa and Tom – Credit: Karen Wilkinson

However, 2018 ended up being a very unusual field season. On June 25th, northern bottlenose whales (NBWs) were sighted in the bay by whale-watching guides, the first time since 2013. This was a highly unusual coastal sighting. In fact, this marked the start of a remarkable four-month period: between June 25th and October 15th, NBWs were sighted on at least 64 occasions during 49 days. An absolute joy for whale-watching passengers, they were unsurprisingly challenging to watch during the first month, diving for about 20 minutes and traveling far between dives.

2018 Iceland: A dark ending…

However, from the end of July, their behavior started to change, with groups increasingly sighted in shallow water and a rise in surface activity – breaching, tail slapping, and swimming in tight circles. This marked the start of a few tragic months. Six whales were found dead in the bay between July 25th and September 8th, and at least five of them were females.

Stranding photo by The University of Iceland’s Research Center in Húsavík

The first individual was a live-stranding adult female on a long, gently sloping beach south of the bay. Regrettably, nobody in the area was trained to respond to stranded marine mammals. She died soon after she was reported. During the next week, these concerning shallow-water behaviors continued. Four small animals (always four) swam, quickly back and forth, very close to the dead, beached females. A partial live-stranding of four small animals was videotaped by a local, only a few days after the first stranding.

On August 4th, about 200 m from the first stranding, three small sub-adult females were fatally live stranded. Also, a reported dead stranding of a juvenile occurred on September 8th. On October 11th, another dead animal floated in the bay. During this period, an observed decline in body condition occurred, with visible dorsal ridges indicating a depleted blubber layer and large lesions on some animals. 

Unfortunately there is more…

It’s important to highlight these events were not isolated. NBWs appeared in numerous locations around the north coast of Iceland during the same time period, with similar concerning behaviors in shallow waters. In 2018, at least eight other NBWs were stranded around Icelandic coasts. This series of events overlapped with the largest ever beaked whale UME (unusual mortality event) of at least 100 animals, found stranded on the western coasts of the British Isles. 

The UME provided a massive learning curve for us, young researchers working in the bay at the time – interns from the University of Iceland and the Whale Wise team. We had no experience studying beaked whales, no necropsy experience, and very few resources. Nevertheless, we realized the importance of publishing these results – to our knowledge, these events represented the largest stranding for NBWs and the longest recorded, sustained period in such shallow waters. 

Creating Something Positive out of the Negative

A photo-ID catalog

The first challenge was to examine sightings data from several sources – Whale Wise, interns, whale-watching guides, and locals. We constructed a photo-identification catalog and attempted to reconstruct a behavioral timeline from these same sources. Working from such an opportunistic observation effort was interesting, to say the least. This work would not have been possible without the amazing efforts of Húsavík’s whale-watching guides, captains, and companies, who were more than happy to share their sightings and photos. Special thanks to North Sailing, our opportunistic research platform in the bay!

A whale vet on a holiday

The second challenge was to access stranded animals and collect samples. This involved borrowing friends’ vans and lunatic driving over dunes to sample the four live-stranded animals. With no senior researcher around at the time, our greatest stroke of luck was a chance connection with Thierry Jauniaux. He is a marine mammal pathologist at the University of Liège (Belgium). As chance had it, Thierry had stopped in Iceland on a sailing holiday! He kindly agreed to conduct the partial necropsy of this first female. We collected a variety of samples, such as blubber, skin, muscle, and optic nerve. We are hoping that these samples can be processed soon. Thanks to Thierry, the research center now has a necropsy protocol for future researchers. 

Tom Grove taking a sample from a deceased NBW – The University of Iceland’s Research Center in Húsavík

Why did the whales beach themselves

The third challenge: to find what caused these stranding events. Unfortunately, due to our opportunistic data collection nature, we haven’t been able to answer this. However, the first sighting of northern bottlenose whales in the bay coincided with the planned start date of a NATO-led anti-submarine naval exercise (Operation Dynamic Mongoose), in the Norwegian Sea, to the northwest. This type of exercise has been responsible for mass-stranding events in beaked whales. Hopefully, the processing of the collected samples can yield more answers. 

Finally, we wanted to publish our results. Two members of the 2018 Whale Wise team (Tom and Danny) were fortunate to join students, interns, and the research center’s director (Prof. Marianne Rasmussen) in this effort. We decided to try Marine Mammal Science. Several months and three submissions later, the journal finally accepted our manuscript. Massive thanks to the reviewers! Their critical but constructive criticism helped us highlight our scrappy data and better present it. Most of the authors were very early career researchers for whom this was their first publishing experience. Check out the article here.

The Take-Home Message

For me, Tom, the biggest takeaway wasn’t even based on science. I had never given much thought to this species, but I witnessed firsthand the whales’ social and gentle nature towards each other. They touched each other tenderly, seemed to grieve, and illustrated strong bonds. Despite their tragic end, I hope that these events helped a few more people to fall in love with this enigmatic species. These events held not only a scientific but an emotional significance.

2020 Scotland: The Science Continues for Whale Wise

2018 sparked an interest in and love for NBWs in the Whale Wise team. We started asking Icelandic fishers about their sightings, pestering NBW researchers, and discussing future beaked whale research. We didn’t think that would come as soon as 2020, and certainly not on the Scottish west coast. 

2020 has been yet another tragic year for beaked whales around the British Isles coast, including the largest ever reported stranding of NBWs – seven animals live stranded on August 19th in Ireland, and only one survived. Meanwhile, NBWs were regularly sighted in sea lochs around the west coast of Scotland between September and November.

Northern bottlenose whale breaching in Scotland – Credit: Steve Truluck

Taking that Research Opportunity

After hearing about three animals consistently sighted in Gareloch, we (Alyssa, Tom, and friend Valentina) decided to visit the area for a weekend in late September. We brought a camera for photos, a voice recorder for real-time behavioral observation, and a theodolite to track surface movement patterns. Since these animals hadn’t left the loch in a few days, we wanted to see if any bathymetric features prevented their exit. We were also fortunate to work with Denise Risch, a cetacean acoustician, who deployed a hydrophone on the weekend in the area. We hope to have some results in the next few months.

Sadly, these animals were in poor condition. At least two animals had visible dorsal ridges, indicative of a thin blubber layer. They also appeared distressed, with the largest animal frequently breaching and all animals regularly tail slapping. The two smaller (skinnier) animals would often log at the surface less than 50 m from the shoreline. Gareloch is home to Faslane, a major British naval base that holds the fleet’s nuclear submarines. Next week, the west coast of Scotland was going to host Exercise Joint Warrior, a multi-national naval exercise involving both ships and subs. The NBW’s timing was disastrous.

BDMLR and Whale Wise’s efforts

The story of these animals after that weekend is now quite famous in the British media. British Divers Marine Life Rescue has done a fantastic job monitoring these animals throughout (we were lucky to join them for another weekend of monitoring in October). Before Joint Warrior officially began, they organized a vessel-based operation to herd the animals out of the loch. Despite best efforts, this was unsuccessful. At least four bottlenose whales have died in the ensuing weeks, including a live stranding near Glasgow city center. BDMLR attempted to rescue the two live stranded animals, sadly with no success.

Moving Forward…

So another year of NBW strandings, another year of limited sucess – what can we take away from it? For me (Tom), there are two lessons learned here:

  1. Make use of the media. NBWs were on British national and international news – a significant result. Our family, friends, and colleagues were talking about these whales and the challenges they faced. For some time at least, they were transformed from a forgotten species of the deep to personable characters worth a million blog posts.
  2. We need a reactive network of cetacean researchers in the UK and beyond. A similar problem was encountered in Iceland – researchers tend to plan their work months and stick to these core aims during the field season. This is important, but cetaceans are also unpredictable. We need to respond quickly to these unexpected sightings and strandings to maximize data collection from these rare opportunities. For an offshore species such as NBW, this is doubly important. In this instance, our friend Steve Truluck encouraged Denise and us to collect some data from these whales as soon as possible – thanks, Steve. 

Sources and Further reading

Thank you for reading! If you enjoyed reading about beaked whales, make sure to read our post on the impact of military exercises on beaked whales.

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