Flippers
Definition
Penguin flippers are highly modified wings that have evolved into rigid, flat paddles optimised for underwater propulsion rather than flight. The bones are fused and flattened, and the joint mobility found in flying birds is almost entirely lost. Flippers allow species like the gentoo penguin to reach speeds up to 36 km/h underwater. The short, dense feathers covering the flipper reduce drag, and the stiff leading edge acts like a hydrofoil, generating lift on both the upstroke and downstroke.
Related Terms
The keel is an enlarged ridge on the sternum (breastbone) that anchors the powerful pectoral muscles penguins use for swimming.
Countershading is a camouflage strategy in which an animal's dorsal (back) side is dark and its ventral (belly) side is light.
Porpoising is a swimming technique in which penguins leap out of the water in shallow arcs while travelling at high speed, resembling the motion of dolphins or porpoises.
Related Species
Species where flippers is especially relevant.
Frequently Asked Questions
What does flippers mean in penguin biology?
Penguin flippers are highly modified wings that have evolved into rigid, flat paddles optimised for underwater propulsion rather than flight. The bones are fused and flattened, and the joint mobility found in flying birds is almost entirely lost. Flippers allow species like the gentoo penguin to reach speeds up to 36 km/h underwater. The short, dense feathers covering the flipper reduce drag, and the stiff leading edge acts like a hydrofoil, generating lift on both the upstroke and downstroke.