Shutter speed is the length of time your camera shutter is open, exposing light onto the camera sensor. Essentially, it’s how long your camera spends taking a photo. When you use a long shutter speed, you end up exposing your sensor for a significant period of time, which has a couple important effects on your photo.
Chart: How to Choose the Right Shutter Speed for the Right Situation
https://photographylife.com/what-is-shutter-speed-in-photography
Wildlife Photography and Shutter Speed
For my own shooting style, and when using focal lengths from 200mm upwards, I try to shoot at the following speeds:
Static subjects – 1/500sec to 1/800sec. Faster when using very long lenses.
Slow-moving subjects – 1/1000s to 1/1600s (Animals walking, or running slowly).
Fast-moving subjects – 1/2500s to 1/4000s (Birds flying, animals leaping, playing, fighting).
Obviously it is possible to get sharp images at much slower speeds, and we all do. The shutter speed ranges above are what I try to shoot at in ideal lighting conditions. In nature, such conditions don’t happen every day.
Most often, the amount of ambient light determines what shutter speed I can comfortably shoot at but it is still good to have some idea.
The guidelines described in this post really pertain to hand-held wildlife and nature photography. They will not be relevant when shooting from a tripod or when photographing inanimate subjects.