When in season, I found male Easterns/northerns would gladly attempt to nail any female offered to them. But they were only good for one successful "session" per day. Its almost like they have a beer and smoke afterwards then take a nap
One year I had a male that I rotated through 6 females in a 3 week window. Some had 3 successful matings other just the once, but they all fell gravid. If the female isnt ready and wants to take the male to fight club, the biffo can put the male off his game for that day too.
Cheers,
Dave.