The tern colony at Cemlyn has always been the key feature of the reserve, but there are occasionally poor years where breeding fails. Whilst this is a natural occurrence, it is always disappointing to see. This occurred most recently in 2017, when the colony abandoned the site entirely. Thankfully, this was not a total disaster for any of the species using it – terns are long-lived species and it appears that a significant number of the Sandwich terns at least may have successfully bred elsewhere.
However, Cemlyn remains an important site for terns, and we were very relieved when, after a very slow start, the colony returned in 2018. Although numbers were much lower than in recent history, the colony was still very healthy by comparison with 2017! In total, over 500 pairs of Sandwich tern nested and successfully fledged at least 180 chicks. Small groups of Arctic and common tern also nested, fledging 7 and 10 chicks respectively, whilst black-headed gulls (an important species for the protection of Sandwich tern against predators) successfully fledged around 100 chicks from over 220 nests. Whilst these numbers may appear low, this should actually be recognised as a very successful recovery season – promising, too, for an increased colony again in 2019.