Eric N. Johnson

Animal Life

March 26, 2002

Sideways Vision

The ability to fly gives birds an advantage to see everything with a better view. But with the falcons, hawks and eagles this advantage is altered slightly. In these types of birds a disadvantage is present. This inconvenience is were the eyes are placed on the head of the bird, on the side. "Falcons, hawks and eagles must turn their heads by about 40 degrees to one side to get the best view of what lies dead ahead—which is why perched birds of prey often twitch their heads from side to side"(Adam 1). The problem with having eye placement on the side of the head is when the bird dives at its prey. If it dives straight it could lose what is in front of it. If the bird turns his head during the dive it could so his plummet to its prey. So with a down spiral plummet the bird can achive maximum speed while keeping his eyes on the prey at all times.

Adam, David. "Falcons spiral in for the kill." Nature Science, 24 November 2000.

March 12, 2002. http://www.nature.com/nsu/001130/001130-2.html