These relatives of the bottlenose dolphins are sometimes seen on our wildlife tours, but usually from a distance. They can be hard to spot as they are shy and like stay lower in the water and nearer to shore. They are much smaller than the dolphins, about 2 metres in length and 60kg in weight, and they usually avoid their larger cousins and do not leap to announce themselves.
Harbour porpoises share the countershading markings common to all of the dolphins and porpoises, but their backs are very dark grey or black with a white belly. They have shorter noses and flatter teeth as well. One of the names for harbour porpoises is “the puffing pig” because of the noises they make when they blow as they surface for air – it sometimes sounds a bit like a human sneeze!
More solitary than the gregarious dolphins, they usually move around alone or in pods of 2-4, though they may gather in groups of up to 12 for hunting – often for herring, mackerel and sand eels which they hunt at dawn and dusk when these fish tend to move closer to the sea surface to feed. They also eat other fish and crustaceans.
Female porpoises will start to breed at 3 to 4 years of age and will have a single calf every 1-2 years between May and July.
In the spring and autumn, harbour porpoises will often gather into large groups for migration.