Head to head
Great Hammerhead Shark vs Great White Shark
The great hammerhead and the great white are both very large sharks that reach roughly the same length, around 5 to 6 metres, and both are apex predators. But the hammerhead is built around a bizarre wing-shaped head and a diet of rays, while the great white is a heat-generating hunter of seals and other marine mammals, and the two live quite different lives.
| Great Hammerhead Shark | Great White Shark | |
|---|---|---|
| Head | Wide flat cephalofoil with eyes at the tips | Conical, pointed snout |
| Body temperature | Cold-blooded, matches the water | Regionally warm-blooded; muscles, gut and brain kept warm |
| Main prey | Stingrays, plus other rays, bony fish, and smaller sharks | Seals, sea lions, dolphins, fish, and other sharks |
| Hunting style | Uses the head to pin rays to the bottom | Ambush from below, sometimes breaching to catch seals |
| Length | Commonly 3.5 to 4 m, up to about 6 m | Commonly 4 to 5 m, up to about 6 m |
| Weight | Up to around 450 kg | Up to around 2 tonnes |
| Danger to humans | Rarely bites people | The species behind the most recorded fatal shark bites |
| Conservation status | Critically Endangered | Vulnerable |
Hammerhead vs Great White: common questions
What is the hammerhead head actually for?
Several things at once, and biologists are still weighing which mattered most in its evolution. The wide head spreads the shark's electroreceptors, the ampullae of Lorenzini, over a much larger area, giving it a broader sweep for detecting the faint electrical fields of prey buried in the sand, which suits its habit of hunting flatfish and rays. The eyes at the tips give it excellent vision to the front and, by swinging its head, essentially a 360-degree view. The head also acts as a hydrofoil that improves lift and sharp turning. And great hammerheads use the flat head directly as a tool, ramming and pinning a stingray against the bottom before biting chunks out of it.
Which is bigger and which is more dangerous?
They are similar in length, both reaching about 6 metres in exceptional individuals, but the great white is far heavier, up to roughly two tonnes against perhaps 450 kilograms for a big hammerhead, because the white shark has a thick, muscular, torpedo-shaped body while the hammerhead is comparatively slim. In terms of risk to people, the great white is responsible for more recorded bites on humans, including most fatal ones, than any other shark, largely because it hunts in the cool coastal waters where people surf and swim and it sometimes mistakes a person for a seal. Great hammerheads are large and capable of hurting someone but very rarely do; encounters are usually a curious, cautious shark that moves off.
Why is the hammerhead Critically Endangered when the great white is only Vulnerable?
Both are slow-growing, late-maturing sharks that produce few young, so neither can withstand heavy fishing, but the great hammerhead has been hit harder. Its very large fins are prized in the shark-fin trade and fetch high prices, so it is specifically targeted, and it is also caught as bycatch on longlines and in nets. Crucially, the great hammerhead is one of the most fragile sharks on a line or in a net, with a very high chance of dying from the stress even if it is released alive, so catch-and-release does little to help it. The great white, by contrast, has been given legal protection in many countries, is not targeted for its fins to the same degree, and its populations in places like the northwest Atlantic and parts of Australia have shown signs of recovery.