Field guide to the most commonly encountered mammals and birds

Here, we provide some basic information regarding commonly observed species (plus some others about which we have had queries).  

Feel free to contact us by email if you have any questions regarding species you have encountered on the site.

For more information about mammals, we recommend the Mammal Society's species hub, here, and MammalNet here. For birds, excellent resources are available from the RSPB (here) and the BTO (here).


Common UK Mammals All UK Mammals Common UK Birds All Species All Deer

Grey Seal

Scientific name: Halichoerus grypus

Family: Phocidae

Appearance: The Grey Seal is larger than the Common (or Harbour) Seal but also displays a variety of coat patterns with different degrees of blotching. However, it is generally dark grey above and pale cream underneath. Grey Seals have a long head with almost parallel nostrils (unlike the ‘V-shaped’ nostrils of the Common Seal) and the muzzle of the males is much longer than that of the females. Differentiating between Grey and Common Seals is most reliably done by gauging the position of the eyes. In the Grey Seal the eyes are situated half-way between the end of the muzzle and the back of the head (one-third in the Common Seal).

Size: Head and body 1.8-2.1 m; Weight 105-310 kg.

Natural history: Grey Seals are very large mammals and spend much of their time out at sea where they feed on sand eels, cod and any other fish that may be locally abundant. Between tides however, they haul out on rocky outcrops and secluded beaches where they may gather in large numbers. Little aggression is seen at haul outs except at breeding colonies where females try to maintain a distance of around 3 metres from other individuals. Breeding varies depending on location around the coast with mating taking place between September and December. A single pup is then born the following season on land where it is fed on milk for about 3 weeks before being abandoned. The pups are born covered in a creamy white fur which is moulted after about a month.


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