Arctic Species: Thick-billed Murre

No, there are no penguins in the Arctic, but the Thick-billed Murre (or Brünnich’s Guillemots) often causes for confusion. Being a perfect example of convergent evolution, the auk-family (where the Thick-billed Murres are part of) and the penguins are completely not related bird families that evolved in the same direction as the conditions they live in are very similar. Apparently having a black and white plumage and being streamlined with small wings is an advantage in polar regions.

Thick-billed Murre

Which makes sense as their colour gives them good camouflage in the water. When seen from below, one sees the white undersides against the light coloured skies and from above the dark uppersides are barely visible against the dank water. And as both families specialise in catching their food underwater, being streamlined and having short wings is also a big help. Thick-billed Murres mainly live on a diet of small fish and crustaceans.

Thick-billed Murres flying around at a colony

There is one difference between the auks and the penguins: the former still have the ability to fly. In Antarctica, there are no land predators so penguins can safely breed anywhere on land. In the Arctic, there are several land predators (e.g. Arctic Fox and Polar Bear on Spitsbergen), which means the birds have to find a safe place to breed. In case of the Thick-billed Murres, this is steep cliffs. Here they are safe for predation by foxes and most bears (although not every bear…). However, this means they still have to fly. Because of this, their wings are a bit a mix of the short stiff ‘flippers’ they need underwater and the broader, larger wings they need in the air.

Thick-billed Murres at their colony

They lay their eggs on a small ledge on the cliff, without really making a proper nest. The parents take turn incubating and later, when the egg has hatched, in feeding the chick.  During this period, one parent always has to stay with the chick to protect it from predation by Glaucous Gulls and Skuas, so only one parent can go out and catch a single fish to feed the chick before it can go out again to the feeding grounds.

Thick-billed Murres in the water near the colony

When the chick is around three weeks old, it needs more fish as the parents can bring. Even though the chick is still too small to properly fly, the parents force it to jump from its ledge so they can swim with the chick to the food. The chick spreads its little wings and glides towards the ocean.

A small chick gets pushed in the air by one of the parents in order to make it to the ocean

For many predators, this is, of course, the moment they have been waiting for. Many of the chicks don’t make it to the water and crash land on the tundra underneath the cliff. Here Arctic Foxes, Glaucous Gulls and Arctic Skuas await them, hoping to get an easy meal and stock up their food cashes to get them through the leaner times later on. When a chick crashes on the tundra, it immediately starts running to the shore, but those predators are usually a lot quicker.

A bonanza for Arctic Foxes

Fortunately, they all jump together and there are only so many chicks that can be caught at the same time by the predators. So most of them make it to the ocean, where they will swim with their father to the rich fishing grounds in the North Atlantic. It usually still takes another month and a half before the chicks can finally really fly.

When they make it to the water, the parents have some explaining to do to their angry kids.


One comment

  • This was a bonanza of murres that I thoroughly enjoyed, Arjen. Each time I scrolled to the next photo, there was another amazing sight. And then on to the next, with the compelling narrative leading the way. Until I thought, no, is there really going to be an arctic fox next? And there was, not only that, it had a murre in its mouth. Fantastic story with drama, magnificence, sadness, and even a whimsical ending. Loved seeing the aerial photo of the parent pushing the chick–what an incredible phenomenon, one that I was not familiar with. Also really appreciated the sheer abundance of this magnificent bird. Thank you.

    Liked by 1 person

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