Honestly, I have no clue, but when I see them jump between trees, based on the general trajectory they take, it looks like a 3:1...maybe 4:1 @ best. How the cat has managed to catch five of them (and a few bats) this season is beyond me!
The best (skydiver) wing-suits (post 2000 AD) glide at 3:1 or 4:1.
The biggest wing-suits overlap glide performance of the smallest parachutes (say 50 square feet). They stretch straight across the feet, then straight forward/up to wrists ... like the flying squirrel in your photograph.
One British movie stunt man even landed his huge wing-suit in a giant pile of cardboard boxes!
Talk about large and furry testicles!
Kudos to your cat for catching so many flying mammals.