Wildlife of Skomer

Manx Shearwater Puffinus puffinus

Manx Shearwater Puffinus puffinus

Skomer Island provides a fantastic habitat for ground nesting birds. An accurate census of puffins is difficult, but a count in 2016 indicated over 22,000 birds.

Manx shearwaters also do well on the island. There are an estimated 316,000 breeding pairs on Skomer with Skokholm Islands breeding pairs this makes the two islands the largest known concentration of this species in the world.

The waters around the island are also home to some incredible wildlife, like the dolphins featured in this video who came into North Haven, where the Dale Princess boat lands.

Skomer Island is part of a Marine Conservation Zone which is managed by Natural Resources Wales/Cyfoeth Naturiol.

What’s the difference between Guillemots and Razorbills?
crowded guillemot colonies by Chris Taylor

Crowded guillemot colonies by Chris Taylor

Guillemot; Thin pointy bill Long – bodied Dark brown above

Razorbill; Wide bill, crossed by white lines Stocky build Black above with white line in front of the eye

In flight – the feet of the Guillemot protrude beyond the tail but stop before the tail tip in Razorbills.

Colonies – Guillemots nest in large, crowed colonies whereas Razorbills are more spread out on cliffs and under boulders.

 

Why do the Guillemots build nests so close together?
The main reason for this is safety in numbers. No other bird breeds in such close proximity.
There are about 20,000 individuals breeding on Skomer.
Where do the Puffins, Guillemots and Razorbills feed?
All three species feed in the Irish Sea. The exact location will depend on where the food source happens to be at the time.
What’s the difference between Herring, Greater Black Backed & Lesser Blacked Back Gulls?
Herring Gully by Kurt Kulac

Herring Gully by Kurt Kulac

In adults;

Lesser Black-backed Gull;
Smaller than Herring Gull and Great Black-backed Gull
Dark grey back
Yellow legs

Herring Gull;
Bigger than a Lesser Black-backed Gull and smaller than a Great Black-backed Gull
Pale grey back
Pink legs

Great Black-backed Gull;
Biggest gull on Skomer
Black back
Pink legs

Where do all the Gull species breed?
The Lesser Black-backed Gulls tend to nest in flocks inland from the cliffs, Herring Gulls nest
largely on the cliffs and occasionally within Lesser Black-backed Gull colonies and the
Great Black-backed Gulls nest alone on the rocky outcrops all over the island and on
some of the cliffs.
Are Fulmars and Gulls closely related?
No, although they are superficially similar, Gulls and Fulmars are from different families.
Gulls are from the Laridae family and Fulmars are part of the Procellariidae family which is Petrels and Shearwaters.
I saw several bird skeletons alongside the path-is there any need for concern?
No, these are most likely Manx Shearwaters and there are over 120,000 breeding pairs on Skomer so the number seen on walks around the island are only a small proportion of the total number of breeding birds.
Why are only the bodies of Manx Shearwaters eaten?

Most of the shearwater carcasses around the island are left by Greater black- backed gulls, which kill and eat any shearwaters that do not reach the safety of the sea, or their burrow by dawn.

Just like you with your Sunday roast chicken, they usually leave the wings, feet and head behind as these are not easy to swallow or digest.

Why are Manx Shearwaters only seen during night time?
The Manx Shearwater has legs positioned at the back of the body. This is perfect for diving but not for wandering about on land. Therefore they are very clumsy and slow on land. Therefore they only come ashore under the protection if darkness when gulls find it harder to hunt them.
Where do the Manx Shearwaters feed?
By tracking the movements of Manx shearwaters from Skomer using miniature GPS tags we know that they usually feed in the Irish and Celtic Seas. To find enough food for their hungry chick, Manx shearwater parents on Skomer frequently make round trips of 300 km or more, heading north, south or west from the island.
Are all these burrows caused by the Rabbits?
No, the burrow of Skomer are a combination of Rabbit, Puffin and Manx Shearwater burrows.
Would there be Manx Shearwaters and Puffins on Skomer if there were no Rabbits?
Yes, both Manx Shearwaters and Puffins have very sharp claws making them very good at digging. They surely appreciate help from Rabbits but they are not dependent upon them.
Why are many seabirds seen without nests?
Guillemot, Skomer Island

Guillemots, another stunning Skomer resident

Birds without nests could be the other half of a pair waiting for their turn to attend the nest, or checking up on their partner. Alternatively, they could be immature birds sussing out what all this breeding is all about!

Many seabirds take many years to reach sexual maturity. For example Fulmars take about eight to nine years to start breeding and they start visiting land and nesting sites after about four years at sea.

Kittiwakes return to nest sites at the age of two years between May and July to assess the situation and start to breed between three and six years of age.

A final example are Guillemots which take five to six years to reach sexual maturity but visit nesting colonies each year prior to breeding.

Factsheets:

Annette Fayet handling a Manx Shearwater

Annette Fayet handling a Manx Shearwater

Frequently Asked Questions about Skomer

Chough (1MB)

Manx Shearwater (1MB)

Skomer is close to the coast of Pembrokeshire, it is owned by the Natural Resources Wales (NRW) but it has been managed by ourselves for many years. If you are a member of the Wildlife Trust of South and West Wales you can now land on the island for free.