The Razorbill, like the Puffin and the Guillemot is a member of the Auk family.
Razorbills are actually the closest living relative to the Great Auk, which is now extinct. The great auk was considered to be the northern hemispheres equivalent of a penguin, which is very apparent in their appearance. They have a black back, white under-belly and a large blunt black beak.
However, unlike penguins razorbills are capable of flight, although (just like the other Auks) their wing spans are very small in comparison with the size of their bodies, which gives them a very inefficient high energy wing beat. Their wing size and shape renders them far superior swimmers and divers than they are fliers.
The Razorbill’s main diet is sand eels and sprats. They dive deep into the sea using their wings and their streamlined bodies to propel themselves toward their prey. They usually feed at a depth of 25m but they have the ability to dive up to 120m below the surface.
There are around 12,000 Razorbills on Skomer, as well as smaller populations on both Skokholm and Grassholm.The birds only come to land to breed, spending the rest of their time out at sea, where they feel most comfortable.
Razorbills choose their breeding sites carefully, looking for spots which offer good protection from larger predatory birds such as Greater Black Back Gulls and Peregrines. They usually opt for small ledges and crevices protected by overhangs or near caves. Once established, a mating pair will often reuse the same site every year.
Razorbills begin breeding between 3-5 years old. Females will often encourage competition before choosing a mate, but once a male is chosen, the pair will stay together for life.
They do not build nests, instead lay a single egg directly onto the rocky ledges. The adult birds will then take turns to incubate the egg for around 35 days before it hatches. Once the chick has hatched, the parents take turns foraging for their young while the other stays at the nest site.
The birds feel much more vulnerable on land than on the water, so the chicks leave before they can fly properly. Within a few weeks of hatching, they are encouraged to leap from their ledge into the water and the parent bird will then accompany them out to sea, usually under the cover of darkness. Although they won’t be able to fly for a number of weeks they can both swim and dive well at this stage.
After breeding, the Razorbill will winter at sea, sometimes as far as the Western Mediterranean .