Black Guillemot family raised in a nestbox

Black Guillemot (Julian Hughes)

Four members of the auk family nest in North Wales. The most abundant are the Guillemots that line ledges on the Ormes, four sites on Anglesey and a further 14 on Pen Llŷn and its islands. Second are Razorbills, which share some of those colonies but in far smaller numbers, and which also lay a single egg each season. Third is the poster-child of the seabird clan, the Puffins that nest in burrows on a few sites locally and is especially vulnerable to Rats that have become re-established on Anglesey’s Ynys Seiriol (Puffin Island) 20 years after their eradication.

Our rarest nesting auk is Black Guillemot, with just a handful of pairs. We lie on the very southern edge of its climate distribution – although they occur farther south in Ireland. In summer, their glossy black plumage is offset by striking white wing patches, and if you see one close up, the bright red legs, feet and gape (inside the bill). They were probably always scarce here, but ceased breeding in the 19th century, returning as a regular breeder in the mid-1960s, nesting under boulders and in rock cavities.

This is a critical time for seabirds, facing a raft of threats that include bird flu and climate-induced shifts in the fish on which they depend, as well as predation from mammals and disturbance from coastal humans. Black Guillemots are a common sight in Scottish ports where they nest in harbour walls. Artificial nests have been built within the secure part of Holyhead port, and last week four chicks were ringed by BTO volunteers in only the second use of a nestbox, the last being in 2018.

In other auk news, a Razorbill seen on Bardsey this week was ringed there as a chick in 1988, making it – at 35 years – among the oldest recorded in Britain & Ireland. The species' longevity record is also held by a Bardsey bird, ringed as a nestling in 1962 and still alive there in 2004, at 42 years.

A Black Guillemot flew past Talacre last week, unusual so far east during the breeding season, and perhaps the same that has been seen off Hilbre this year. Up to three Roseate Terns are at Cemlyn, with another off Pwllheli, and six Storm Petrels passed Porth Ysgaden in blustery winds on Sunday. Up to 14 Mediterranean Gulls have been on Porthmadog’s Llyn Bach, with others at Llanbedr and Rhos Point.

A White-tailed Eagle, from a reintroduction project in southern England, was tracked across North Wales last week and seen in several places on Anglesey, hunting gulls on the seacliffs. This top predator is also at risk from bird flu: a NatureScot report published last week found that breeding success in the Outer Hebrides has fallen by almost two-thirds, to just 24% following outbreaks of avian influenza.