Skomer Island is renowned for its large breeding seabird populations, including Manx Shearwater, Guillemots, Razorbills, Great Cormorants and Black-Legged Kittiwakes. There are also populations of birds-of-prey, such as Short-Eared Owls, Common Kestrels and Peregrine Falcons. Harbour Porpoises and Common Dolphins are also regular visitors to the surrounding waters. 

With approximately 52,019 (2026) birds, Skomer Island is one of the most important colonies of Atlantic Puffins in Britain, after declining numbers in the 1950s and 1970s, the size of the colony has been slowly growing. Furthermore, the Skomer Vole is an animal unique to the Island, a subspecies of the Bank Vole, it lives in the bracken and reaches to populations of 20,000 strong in the Summer months. 

But it is not all about animals! Skomer is also home to over 248 recorded species of lichen, with several rare and biogeographically distinct lichens on the island. Monitoring programmes have been introduced to track long-term changes in lichen populations, particularly in response to fluctuations in seabird numbers and environmental disturbances, such as oil pollution.