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Mammal of the Month: Orca

Dan Brown

Killer Whales or Orcas are highly social, intelligent and stunning animals. For those of us living in the UK we stand an excellent chance of seeing these ultra-predators close-up off the Scottish coast and now is the time to do it! 
Bull Orca off Shetland (http://www.shetlandnature.net)

Bull Orca off Shetland (http://www.shetlandnature.net)

There is no better time than now to feature the most effective marine predator on our planet. It’s half way through Orca week up in Caithness and this time of year generally marks the start of Orca season up north. Whilst you might not think it, the UK is actually a brilliant place to catch up with the largest, most attractive and charismatic of Dolphins. We tend to think of them as a Norwegian, Antarctic, Argentinean or British Columbian specialty, but they are very regular in the UK and with a bit of time and luck you stand a very good chance of seeing them.

Equally stunning close-up or set amongst stunning coastal scenery

Equally stunning close-up or set amongst stunning coastal scenery

They’ve had a bad reputation in the past; a ferocious predator, a killer of whales and even Great White Sharks, but reality is somewhat different. Yes they do hunt whales, including Blue Whale calves, and yes they can cause the entire Farallones population of Great White Sharks to vanish over-night, but there has yet to be a human fatality involving a wild Orca. They are exceptional social and intelligent, in fact the populations along the west coast of North America have one of the most stable societies known among non-human animals. Their social structure is matrilineal within which is clearly defined hierarchy. The matriline is the most basic of social tiers and is most often what we see in British Orcas, ie a group of up to ten or so animals keeping very close company. These groups very rarely break apart, and if they do its only ever for a few hours. The next social tier up is the pod. This consists of several (normally 1-3) matrilines of related animals, but these may separate for several weeks at a time. In the Northern Isles we frequently see several groups of animals appear at roughly the same time, these are likely to be separate matrilines from within a pod. The third social tier is the clan which brings together all pods with similar vocal dialects, a direct reflection of maternal ancestry and an excellent example of a non-human cultural tradition. The final social tier is the community which is defined by pod association patterns and not clan membership. It has been shown that pods may associate with other pods from different clans but very rarely associate with pods from different communities.

A matriline off Caithness recently

A matriline off Caithness recently

Many groups of animals have been defined by their feeding preferences and their movements are often directly related to seasonal abundances in food. Those Orca appearing around the Scottish coast now will predominantly feed on seals and other marine mammals, however later in the summer the same individuals they have been shown to hunt Eiders around the Faeroes and then Herring off Iceland during the winter.

Researchers documenting Orcas off Shetland

Researchers documenting Orcas off Shetland

In the North Atlantic there has been a significant amount to research into the various social groups. Work is still on-going and more information can be found on the Icelandic Orcas Facebook page. Many of the individuals have been photographed well enough to allow individual recognition, and if you are lucky enough to get any images of Orcas these could prove useful in determining the movements of the North Atlantic populations.

'Mousa' a well-known female Orca (characterised by the nicked fin) that spends the summer around Scotland and the winter in Iceland.

‘Mousa’ a well-known female Orca (characterised by the nicked fin) that spends the summer around Scotland and the winter in Iceland.

Orcas are not boat shy!

Orcas are not boat shy!

Globally they can be found in every ocean where distinct populations exist based on behaviour, patterning, and size. Recent research into the genetics of these populations may well reveal the presence of several different species and certainly if you’ve been lucky enough to encounter Orcas around the Antarctic then you may well have noticed the yellow colouration to the normally white patches, these are probably Type B Orca, whilst a similarly coloured but smaller animal will probably be Type C Orca. The population occurring around New Zealand, Type D Orcas are particularly distinct in having a more bulbous forehead (melon), a much reduced white eye blaze and a very sickle-like dorsal fin. This recent video by the Sea Shepherd off New Zealand nicely illustrates the latter features. Of course we should probably give these true Birding Frontiers names such a Sickle-finned Sea Panda, and Dwarf Sea panda, suggestions welcome 😉

It would be good to get this combo in the UK!

It would be good to get this combo in the UK!

A young bull with a typically triangular dorsal fin

A young bull with a typically triangular dorsal fin

The ID of Orcas is very straightforward although just occasionally slow moving, distant groups of Risso’s Dolphins may be mistaken for Orcas with their tall dark dorsal fins. Hopefully any half decent view of the body of head should reveal the correct identity.

The only confusion species - Risso's Dolphins have tail dark fins and can be confused with Orcas at a distance.

The only confusion species – Risso’s Dolphins have tail dark fins and can be confused with Orcas at a distance.

Sadly Orcas are still being captured for our entertainment. Russia appear to be the biggest problem makers yet venues in the States still support the use of captive Orcas for our entertainment, something that will hopefully change under the weight of public pressure. Thankfully they are still widespread and relatively common and here in the UK there is a very good chance of encountering them in the wild given a bit of patience and making sure you’re in the best areas.

When and where to see Orca

Orcas can be encountered at any time of year around the Northern and Western British coasts, however the best time is late Spring and Summer around the Northern Isles and Caithness.

Orca Watch is currently running, based at Duncansby Head, Caithness and will be daily until Saturday. Start times for meeting are as follows:

Weds 27th 11am, Thurs 28th 12pm. Fri 29th 1pm & Sat 30th 2pm

Keep an eye on the Caithness Swatch Facebook page for up to date sightings. So far this week they have had Orca, Humpback Whale breaching on two days, Minke and other common cetaceans.

Other good spots in Caithness include Noss & Dunnet Head, as well as Strathy and Stoer Points in Sutherland. The advantage of the Caithness coast is the linear nature of it making tracking these animals relatively easy. Other hotspots such as Orkney and Shetland have many islands and voes for cetaceans to get lost in, as well as proving difficult for the observer to track them.

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You cant beat looking down on Orcas from the Scottish coast!

You cant beat looking down on Orcas from the Scottish coast!

On Orkney, Scapa Flow and the Southern Islands seemed to be particularly favoured.

Female and calf in Scapa Flow, Orkney

Female and calf in Scapa Flow, Orkney

Play-time for a juvenile Orcas in Scapa Flow

Play-time for a juvenile Orcas in Scapa Flow

On Shetland, Mousa Sound, Yell Sound, and Sumbrugh Head all have regular sightings, and a trip with Shetland Nature offers an excellent chance of connecting with Orcas.

Orcas are not shy of being close to the coast which often allows for amazing views (http://www.shetlandnature.net)

Orcas are not shy of being close to the coast which often allows for amazing views (http://www.shetlandnature.net)

Elsewhere the Hebrides and Western Ireland, as well as the Minch all have occasional sightings.

Further afield The Strait of Gibraltar, the Lofted Island off Norway and Iceland are the top three places in the rest of Europe for catching up with Orcas.

A juvenile Orca off Caithness two weeks ago

A juvenile Orca off Caithness two weeks ago

More juvenile Orca fun!

More juvenile Orca fun!

And finally…

No doubt you will all have seen these before but some excellent videos showing the amazing hunting, social and inquisitive element of Orcas:

Try and ignore the backing music but a great example of Orcas hunting Dolphins

Orcas deliberately beaching themselves in Argentina to hunt sealions

Fun or hunting!?

The inquisitive side of Orcas!

 

One thought on “Mammal of the Month: Orca

  1. petchary

    Fantastic photographs, thank you! I saw a group of Orcas hunting a sea lion in rough, foggy seas off the coast of Monterey, California a few years back! An unforgettable experience…

    Reply

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