I'm guessing if you unweighted your front wheel, you'd almost not feel 'em. But it'd certainly feel you, so go *fast!*

Deer. Grr. Growing up in WI and learning to drive with that sort of "Is that a little reflector on a mailbox or a deer?!" paranoia as soon as it started getting a little dark (or in the spring... or the fall... or all summer...) and having to stop on rural roads and counting 5-10 of them cross in front of my little car, after not seeing a SINGLE one while out hunting... I don't feel too bad for them when they're in those midwestern states where they breed like rabbits and just wander from corn field to corn field... (or soybeans, or alfalfa, or...) but I do feel for them when in the 'new' suburban communities (like the ones called "Oak Grove" etc where the actual oak grove was bulldozed to pop up about fifty houses that all look alike?) and they seem so lost, because just last year that was a decent habitat...

Turkeys are SOLID and I would NOT want to hit one. All the same, they're also more wary than deer tend to be.

...squirrels are suicidal.