J@n!t---It absolutely helps finished drawing. Life has got in the way of my drawing regimen over the last couple years, but as I say and display in my sketchbook--plug!plug!---I used to start every drawing session with about an hour of gestures like these, reffed from photos, anatomy books or comics. I think even my posts here show more fluid, confident mark-making as the series progresses.
I admire the economy and subtle line in your gestures. One of my favorite fiugrative artists here, AztecFireFlower, advised me to culitvate just these values in my own drawing. Accordingly I'll be altering my drawing pattern to beginning with my pen never leaves the paper, lines race through as well as around the drawing, but progress to more considered and therefore fewer and more sublte lines.
Plus, your animal studies really make me want to do animals!
"Three's so little room for error."--Elwell