Cetaceans

If staying on the island, please log any sightings of cetacean species (detailing number seen, where, heading in which direction, date & time) in the wildlife log in the Tavern. For those not staying on the island, please notify the Warden of sightings (where these have been made within the MPA or on passage between Ilfracombe/Bideford and the island) via the upload link here, so that your record can be added to others on the island.

Harbour porpoise

The harbour porpoise Phocoena phocoena is the most frequently seen cetacean around Lundy, often encountered on crossings between Lundy and the mainland and vice-versa during the summer months. Typically, they are seen singly or in small groups of two or three individuals or, on occasion, interacting with a larger group of dolphins.

The harbour porpoise is the smallest species of cetacean found in European waters, measuring around 1.3 - 1.5 metres in length and weighing 50 - 60 kg. It is often confused with dolphin species, particularly the bottlenose dolphin (which are considerably larger). The porpoise is rotund in shape, with a small triangular dorsal fin which shows briefly above the surface - usually little of the animal is seen, as it rarely leaves the water entirely. It has a small, rounded head with no distinct beak.

The harbour porpoise is the one designated Annex II feature of the Bristol Channel Approaches SAC, which includes Lundy. This site was designated on the basis that the area between north Cornwall and south Wales is likely to be an important breeding area for porpoise.

Dolphins

Several species of dolphins may be seen around Lundy, often encountered on crossings between Lundy and the mainland and vice-versa during the summer months. The common dolphin and the bottlenose dolphin are the two species most frequently seen, with the former being more commonly seen than the latter.

The common dolphin Delphinus delphis (at one time referred to as the short-beaked common dolphin*) is the most abundant species of cetacean in the world. Growing to 2.7 m in length and weighing up to 150 kg, they can live to be 35 years old. They are an offshore species, so you don’t often see them close to the mainland coast, where bottlenose dolphins are more likely to be seen. They are highly social and are often seen swimming in large groups, travelling at speed and frequently leaping out of the water. An entry in the island logbook for 2011 for 27^th July states: “100+ common dolphins feeding about 1 km off Jenny’s Cove” (Davis & Jones, 2011); and “24^th May 2022: 50-100 common dolphins seen between the island and Ilfracombe”.

Common dolphins can be identified by the ‘hour-glass’ pattern on their sides with a distinctive cross on their sides directly beneath the dorsal fin. On older individuals, an obvious yellow/cream area starts behind the long, narrow beak. Their upper parts are a dark grey, with white below.

* At one time, common dolphins were divided into separate ‘short-nosed’ and ‘long-nosed’ species. However in 2015 genetic studies determined that all populations examined to date would be more logically grouped under one species (D. delphis) with four recognized subspecies of common dolphins throughout the species’ range: the common dolphin (D. d. delphis); Eastern North Pacific long-beaked common dolphin (D. d. bairdii); the Black Sea common dolphin (D. d. ponticus); and the Indo-Pacific common dolphin (D. d. tropicalis) (www.marinemammalscience.org).

The bottlenose dolphin Tursiops truncatus (which may also be known as the common bottlenose dolphin) is the second-most abundant dolphin species seen around Lundy. They are larger than common dolphins, growing up to 4 m long and weighing up to 500 kg. Their natural lifespan is 45-50 years. They are social animals, often being seen in groups of up to 15 individuals. They love to jump out of the water and will happily approach boats moving at speed to bowride, surfing the waves generated by the boat.

Bottlenose dolphins are chunky and grey all over, though darker grey above and paler grey below. The beak is short and stubby and the dorsal fin is large and sickle-shaped, often marked with notches and scratches.

The presence of porpoises and dolphins around Lundy can be detected using underwater remote recording devices (known as ‘passive acoustic monitoring devices’) which record the clicks and whistles made by these cetaceans. In 2011 and 2012, two ‘C-PODs’ were deployed for this purpose, one attached to the wreck of the Ethel off the island’s SW Point and the other to the wreck of the MV Robert off the island’s east coast (see Squires et al., 2014). Wrecks are used as attachment sites primarily because of the ease of being able to attach these buoyant devices to them on lengths of rope, rather than the wrecks acting as possible cetacean congregating sites. More recently, ‘F-PODs’ have been used at Lundy for this same purpose, having a battery lasting for well over 12 months (see Williams, 2022).

Risso’s dolphin Grampus griseus may occasionally be seen off Lundy during the summer months. Whilst this species has an overall light grey colouration (which lightens to white in older individuals), it is the white scars and scratches on the flanks (and sometimes the dorsal fin) that distinguish it. These are created as social interactions between males associated with mating dominance, when tearing of the skin is caused by teeth in the lower jaw.

The Risso’s dolphin typically grows to a little over 3 m in length (males being slightly larger than females) and weighs up to 480 kg in weight. They are found in temperate and cold waters worldwide. They are often found in large social groups, though it is usually just lone individuals which are seen around Lundy. The species is named after a French naturalist, Antoine Risso (1777-1845), who made the earliest studies of the species.

Despite its common name, the Long-finned pilot whale Globicephala melas is actually classified as a member of the dolphin family (Delphinidae). Its large size (it can grow to 6.5 m long) is the reason why it is commonly referred to as a whale. Identifying characters visible on the surface include a low and broad-based dorsal fin set about a third of the way along its back, and a bulbous head without an obvious beak. The colour of the back and sides is very dark grey to black with white underneath. The long flippers may be up to a quarter of the total body length, and it has small tail flukes, although both of these features are likely to be hidden when viewed from above.

Long-finned pilot whales are often observed in groups which may consist of over 1,000 individuals. They occur around much of the coastline of Britain and Ireland, mostly feeding on squid but also on demersal fish species such as cod or turbot. Off Lundy they are rarely seen, most likely being spotted off the west coast, usually in smaller groups of fewer than 20 individuals.

Incidentally, short-finned pilot whales are almost indistinguishable from long-finned pilot whales, but they are found in tropical and sub-tropical waters, whereas long-finned pilot whales prefer colder waters.

Whales

A small number of whale species have been recorded from Lundy’s waters over the years, although they are very rarely seen. The most frequently recorded is the minke whale.

Northern or common minke whale Balaenoptera acutorostrata, a species of baleen whale which can grow to between 8 and 9 m in length. Typically black or dark grey above and white underneath, with a white band on each flipper. The small dorsal fin is positioned about two-thirds of the body length towards the tail flukes. They can live to being 60 years old, although their lifespan is usually between 30 and 50 years. An individual will breathe three to five times at short intervals before "deep-diving" for 2 to 20 minutes. They do not raise their flukes out of the water when diving. They feed on herring, sandeels or sprat. They undertake a seasonal migration towards the Arctic during the spring, returning towards the tropics in the autumn.

Search for ‘cetaceans’, ‘harbour porpoise’ or ‘dolphins’ in the Bibliography for more reports on sightings of porpoises and dolphins at Lundy.

Additional note

All cetacean species within the territorial waters of England, Scotland and Wales are protected under Annex 5 of the Wildlife and Countryside Act 1981. They are also included as ‘Species of Principal Importance’ under Section 41 of the Natural Environment and Rural Communities (NERC) Act, 2006.