Journal of Fluid Mechanics

If you have ever wondered why ducklings always seem to line up behind their mother, it is because swimming in her wake saves them a measurable amount of energy.

A study published in the Journal of Fluid Mechanics found that ducklings positioned correctly in their mother’s wake can save up to sixty-two percent of the energy they would otherwise spend swimming, thanks to wave interference patterns.

That is not a small saving.

It is the difference between a duckling that arrives at the far side of a pond with energy to spare and one that arrives exhausted.