Larger ones, such as emperors, with whom the former share a habitat, can reach 45 centimeters.
This acrobatic technique is actually a survival strategy; It helps them avoid being caught by seals, killer whales and other predators. To rise above the surface, they first propel themselves out of the water by swimming very quickly: they can travel at around 8 km / h when no danger threatens them and triple that speed if they feel threatened. To stabilize themselves before landing, they throw their wings back.
According to a team of researchers from the universities of Bangor and Cork, in the United Kingdom, the trail of bubbles that these birds leave behind plays a key role in the jumps. These small air pockets are caused by the plumage. Before diving, the penguins raise their feathers so that they swell, and when they go out, they swim upwards so that the gas expands and covers them. The layer of bubbles acts as a lubricant that reduces friction and facilitates movement, allowing them to shoot out.
In essence, this technique is similar to that used by engineers to accelerate the movement of ships and torpedoes, although in these cases the propellers end up breaking the bubbles, which slows their progress, something that does not happen to penguins.
