Hunting and Feeding
Orcas are the top predators of the ocean, and they have a wide range of prey they can feed on, including sharks, seals, turtles, rays, porpoises, dolphins (their smaller cousins!), many different kinds of fish, and even whales bigger than they are themselves! This is possible, because orcas use cooperative hunting techniques – they hunt in “packs” and, therefore, are often also called the “wolves of the ocean”.
However, orcas are often very specialized in their diets, so not every killer whale eats everything. It depends on the environment and on the food sources that are available. We have recorded most orcas around Snæfellsnes feeding on fish, primarily on herring. We can confirm the herring hunt when we see orcas with herring between their teeth (see first picture on the right), or when we see birds picking up fish bits (herring bits) next to the orcas that are displaying feeding behavior. Often we can also see the herring on the echometer (“fish finder”), or observe dead fish floating on the surface (second picture on the right).
Apart from herring, we have evidence that the orcas around Snæfellsnes also feed on other fish, as well as on marine mammals, and we will give more information on these rare events soon.
Distribution and Sightings
Orcas can be found in all oceans of the world and are thought to be the second most widely distributed mammal after humans. Around Snæfellsnes, orcas can be seen during the spring, summer and winter months. Autumn (September to early November) is usually the time of year with the least sightings.
In the last three years, we have found certain patterns in occurrence of different orca groups around the peninsula. Some of them seem to visit the area only during the summer months, and some only in winter. So far, we have not seen any of the “winter” orcas during summer, or any of the “summer” orcas during the winter. Often we even see the same group exactly on the same date as the previous year!
Within Breiðafjörður, the orcas have been spotted far towards the North, all along the Northern coast of the peninsula, towards the East (Stykkishólmur), and around the Western tip of Snæfellsnes. They often also appear on the South side of Snæfellsnes during the summer months.
On the left you can see two typical places where orcas can be spotted during the year – in front of the glacier Snæfellsjökull in the summer (upper picture) and inside the fjords in the wintertime (lower picture).
Group Structures and Synchronized Breathing
Orcas are highly sociable animals and are known to live in a matriarchy, which means that the females are the leaders. Often the oldest female in the group is the decision maker, as she is the one with the most experience. We are just about to discover how the group structures for the orcas around Snæfellsnes are built, but so far our observations show female leadership in most small core groups. Often the core group only consists of the female and her offspring, and longer observations will reveal further details.
A manifestation of the strong family bonds orcas have is the synchronized breathing. Orcas do as much as possible in unison, and this is especially apparent when they come to the surface to take a breath – the majority of the time they surface and breathe at the same moment. During bigger group meet-ups the orcas around Snæfellsnes often also form long travel or resting lines, where the synchronized movements are even more obvious.
The upper picture shows a female with her two offspring, the lower picture shows a resting line.