The kingfisher is an incredibly effective hunter. It watches from a perch or while hovering above a pond until it sees a fish, and then it dives, slicing through the water with such speed and ease as if there were no barrier between it and its prey. It makes almost no splash thanks to the aerodynamic build of its bill and head.
Engineers of the Shinkansen bullet train needed to quiet down the noise level of the train, which exceeded environmental standards. Ask Nature writes, "One source of noise was an atmospheric pressure wave forced in front of the train as it traveled through a narrow tunnel, creating a sonic boom at the exit. The bullet-shaped nose was part of the problem."
So, the engineers turned toward nature and the kingfisher, focusing on how it manages to cut into the water with little drag. Its bill is just the right shape to act as a wedge, starting at a point and increasing slowly in diameter until it reaches the skull. This shape pushes water out of the way, rather than ahead of the bird, and this is exactly what the engineers wanted to accomplish with their train -- pushing air out of the way rather than ahead of the train.
The engineers changed the shape of the train's nose to be more similar to that of the kingfisher. This was one of the main ways in which the team found success: "The more streamlined Shinkansen train not only travels more quietly, it now travels 10% faster and uses 15% less electricity."