Examples of this are shooting against the sun or upwards into a tree on a backlit subject.
Although the camera’s aperture priority mode tries to properly expose the scene, wildlife photographers often find ourselves shooting in scenarios with harsh light, as we can’t control the scene. Examples of this are shooting against the sun or upwards into a tree on a backlit subject. Other times, you may be shooting a very bright subject like a white bird against a much darker background. Even though modern cameras are pretty good at metering, these situations can still cause the camera to fail to properly expose your subject.