When in the field studying birds, I love to do gesture drawings to get the feel of the bird. These are quick and do not have to be perfect. They help me to understand what I am seeing.
Here is a gesture of a Piping Plover
I also do line contour drawings.
The idea is to draw fast without looking at the paper rather looking at the bird. This is what I like to call tactile learning. It reinforces what my eyes are seeing or sometime what they are not seeing.
Another contour of sunflowers in Ware County