No.110 · Mammals · Rare visitor
Humpback whale
Megaptera novaeangliae
A 15-metre whale with enormous white-edged flippers and a knobbly head, famous for breaching and singing. Once hunted to near-extinction, it is now seen more often off Britain, including the Irish Sea and Celtic Sea.
When to look
July to September and December to February, mostly at dawn and day.
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Time of day
- Dawn
- Day
- Dusk
- Night
- Best time
- Flat calm days from a boat or a high headland. Sightings peak in the Celtic Sea in July–September, and off the south-west in December–March.
- Where in the game
- the Pembrokeshire coast (sea)
- Size
- 14–17 m; females are 1–1.5 m longer than males
- Weight
- Up to 40 tonnes
- Lifespan
- 50 years or more
- Population
- About 135,000 worldwide today; in Irish waters 120 individuals were photo-identified between 1999 and 2022
- Status
- Casual visitor to Welsh waters; recovering worldwide since the 1986 whaling ban
Diet
Krill and small schooling fish such as herring, sand eels and mackerel, gulped in bulk
Habitat
Continental shelf waters and coasts; migrates between polar feeding grounds and warm breeding grounds
Breeding
Gestation about 11.5 months; a female has a calf roughly every two years. Breeding takes place in warm tropical waters, not around Britain
Field signs
- A tall, bushy blow visible from a long way off on a calm day
- A low, sloping back with a small hump, then the tail flukes lifting on a deep dive
- Seabirds such as gannets diving in one spot over feeding fish
Did you know?
- Each whale has a unique pattern on the underside of its tail flukes, so researchers can tell individuals apart.
- One whale nicknamed 'Humpy' was recorded off the Isle of Man, Pembrokeshire and Cornwall in early 2024.
- In bubble-net feeding, a group blows a ring of bubbles to trap fish, then rises up through the middle with mouths open.
Moments worth waiting for
- Breach
The whale rises almost clear of the water, twists and lands on its side with a crack you hear across the sound.
Photo tip
Use a 200–400 mm lens with a fast shutter (1/2000 s). Watch for the blow first, then get ready for the fluke on the dive. If you can, photograph the underside of the tail for identification and send it to Sea Watch Foundation.
Be a good naturalist
Follow the Wildlife Safe (WiSe) code: keep a boat well away, never chase, never come between a mother and calf, and never put a boat in its path. From the shore, keep back from cliff edges.
The law
All cetaceans are protected in Britain under the Conservation of Habitats and Species Regulations 2017, and deliberate disturbance is an offence