The Wick is the puffin destination — a deep cleft in the cliffs on the south side where puffins nest in burrows along the path edge, standing about with beaks full of sand eels and taking no notice of the queue of photographers a metre away. It is among the easiest close-range wildlife photography in Britain.

The clifftops generally hold guillemots and razorbills packed onto the ledges, kittiwakes, fulmars riding the updraught, and shags nesting on the lower rocks.

The island's interior is riddled with burrows — Skomer holds a huge share of the world's Manx shearwaters, but they only come ashore at night to avoid gulls, so day visitors see the burrows rather than the birds. The night is extraordinary and only overnight guests in the island's hostel experience it.

The bracken and bluebells in late spring hold short-eared owls hunting the Skomer vole in daylight, one of the island's specialities.

The surrounding water holds grey seals year-round, with pups on the beaches in autumn after the seabirds have gone.

Puffins are ashore from around mid-April to late July and leave abruptly. Bluebells peak in May; seal pupping runs through September and October.

Practicalities

Landings must be booked online in advance — there is no turning up on the day. Tickets for the whole season are released the preceding December and the peak June and July dates sell out within days, so this is a trip to plan almost a year ahead.

Boats leave from Martin's Haven for a short crossing, followed by a steep flight of steps up from the landing cove. Daily visitor numbers are capped, the island closes on most Mondays, and crossings are cancelled in rough weather — tickets are non-refundable except when the operator cancels, so allow a spare day.