The unique nose of the Shinkansen 500 bullet train prevents sonic booms whenever it exits a tunnel. It was designed based on the shape of a kingfisher’s beak, which allows it to hit the water at high speed with very little splash. – WTF Fun Facts
Source: https://earthsky.org/earth/sunni-robertson-on-how-a-kingfisher-inspired-a-bullet-train
Darwin’s finches, which are a classic example of evolution, are dying off due to an infectious parasite that damages their beaks. The damage causes their mating calls to have an unpleasant tune, hindering their ability to reproduce. – WTF Fun Facts
Roosters have “built-in” earplugs, which prevents them from damaging their hearing as they crow. When roosters open their beaks fully, their external auditory canals close completely.
Source: https://phys.org/news/2018-01-roosters-dont-deaf-loud-crowing.html
The puffin’s beak is specialized to hold lots of fish. They can carry roughly 5-20 fish back to their nest at a time. Astonishingly, a puffin in Britain once carried 62 fish in his beak! – WTF Fun Facts
Source: https://projectpuffin.audubon.org/birds/puffin-faqs