Acommon visual behavior is the âhead jerk.â This motion is generally observedwhen an individual otter approaches a raft of sea otters. The approaching otternoses and sniffs the other otters while jerking its head from side to side.
Axis tilt is the vertical angle at which the ball rotates. Axis tilt is what is commonly known as spin. Axis tilt is determined by the position of the thumb during the release. If the hand turns too early, the thumb exits on top of the ball. Bowlers with a high degree of axis tilt will be able to see the top of their hand during the release and follow through.
(The axis the planet spins on has considerable wobble, meaning its angle changes over time.) A few million years ago, the tilt of the axis of Mars was 45 degrees instead of its present 25 degrees. Its tilt, also called obliquity, varies greatly because its two tiny moons cannot stabilize it like our moon.