Head to the coast in early spring and you may well get the sense that something is stirring; those once-quiet winter cliffs now peppered with the fidgeting bodies of returning seabirds.
After spending winter at sea, many of our seabirds return to Britain's shores to breed, making spring an excellent time to head for the coast for your first seabird sightings.
One of the most charaterful seabird families is that of the auk. It's likely you will recognise the puffin and the guillemot, but did you know they are five species of auk that regularly occur in the UK?
In our guide, we take a closer look at these charismatic birds, revealing what they eat, where they make landfall and how to identify them.
What is an auk?
Auks – or alcids – are a type of seabird of the family Alcidae. They are small to medium in size (15cm–45cm in length) with short tails and legs, small wings and an upright posture.
Most auks have evolved to become expert underwater swimmers, sacrificing their agility on land and in the air - though they can still walk and fly. Large breast muscles and specially adapted wings enable them to 'fly' underwater in pursuit of their prey.
What do auks eat?
Auks are pursuit divers and catch almost all of their food underwater. Diets vary from species to species but generally include fish (such as sandeels, sprats and herrings), crustaceans, and sometimes plankton.
How many auk species are there in the UK?
There are 23 species of auk in the world, making it a relatively small bird family. Five of these species regularly occur on UK coastlines: puffins, razorbills, guillemots, black guillemots and little auks.
There are a number of other auk species that occasionally make landfall in the UK, including Brunnich's guillemots, long-billed murrelets and ancient murrelet tufted puffins.
Guide to the UK's five auk species
Razorbill, Alca torda
A big, chunky blunt bill separates this species from the more numerous but similarly sized guillemot. Largest colonies are found in the north and west of the UK and around 130,000 pairs breed annually.
Razorbills weigh 590-730g, are 37-39cm in length, and have a wingspan of 63-67cm. Their diet consists of fish.
Black guillemot, Cepphus grylle
With its white wing flash and scarlet legs set against an otherwise black body, this is a striking bird. Pairs breed alone on small islands rather than in huge colonies. Some 20,000 pairs recorded.
Black guillemots weigh 300-460g, are 30-32cm in length, and have a wingspan of 52-58cm. Their diet consists of crustaceans and fish.
Guillemot, Uria aalge
Nests on sheer cliffs around the UK in huge, noisy seabird ‘cities’. There may be a million pairs across the British Isles. Head and back colouration is slightly browner than close relative the razorbill.
Guillemots weigh 850-1,130g, are 38-45cm in length, and have a wingspan of 64-73cm. Their diet consists of crustaceans and fish.
Puffin, Fratercula arctica
Found in and around the big seabird colonies but nests at the tops of cliffs in rabbit burrows on grassland. Bill only takes on its rainbow colours during the breeding season. Over 500,000 pairs breed in the UK.
Puffins weigh 320-480g, are 26-29cm in length, and have a wingspan of 47-63cm. Their diet consist mostly of sandeels.
Little auk, Alle alle
Not much bigger than a blackbird, this is a winter visitor to our coasts – especially after gales – before and after breeding in the Arctic. A short bill and stubby wings, it flies low over the water’s surface.
Little auks weigh 140-170g, are 17-19cm in length, and have a wingspan of 40-48cm. Their diet consist of plankton and small fish.
