Cropping and splitting a video clip may be necessary, especially when multiple cages will be recorded simultaneously. Also, since the videos can be 1-1.5 hours long, you may consider splitting the video in half (your choice) if analyzing everything in one sitting may be a bit overwhelming.

See these following video links:

Cropping a Video Clip: https://www.youtube.com/watch?v=kHmzhqKjm1g

Splitting a Video Clip: https://www.youtube.com/watch?v=zZZpKUaJK-g