The Prespawn
There is no specific time period or water temperature at which the prespawning activities occur, rather they occur over a range of times and temperatures. This is nature's way of protecting the species against radical environmental swings by having fish enter the prespawn and spawning modes at different times, temperatures, water levels, and water clarities. Generally speaking however, smallmouth bass will exhibit prespawn characteristics in waters ranging from 50 to 58 degrees, while largemouths will do the same in water temperatures ranging from 55 to 63 degrees.
The prespawn period is marked by a number of changes in the physiology of the bass as it enters the beginning of the spawning cycle. These are all changes that are working to the angler's advantage. As both an avid hunter and fisherman, I can draw a similarity between, bass behavior during the prespawn and rutting behavior seen in animals. Just like a Tom turkey chasing hens, or a buck in the rut, a bass will throw caution to the wind and go against its instinctual cautious behavior in pursuit of food, a partner, and a spawning site. Add to this the aggressive, protective nature of bass in guarding their beds during the spawn, and you have every angler's dreama hungry, horny, & aggressive fish! Kinda reminds me of my college years.