ujm: Doesn’t create more deer, but because their living areas are being taken over and they are limited to smaller areas, they are more likely to be in the same areas as people. (No where else to go.)
And more likely to need to cross back and forth on the roads, in search of food.
The above is why you’re more likely to see them — and run into them — in Monsey than, for instance Sloatsburg.