Just a thought here wrote:
Animals do have a sense of time on a smaller scale then days, seasons or years. A rat can learn to time a response very accurately. You, for instance, can train a rat so that he will only get a reward if he pushes the lever say 5 minutes after he last got rewarded. If you then look at his response rate you can clearly see that he can estimate 5 minutes very well. If you then give the animal speed, his estimate of 5 minutes becomes shorter (as if time is going faster). Conversely if you gave the animal Valium he responds as if time is moving slower.
Good point about the rats. I've seen those types of studies, too. However, it is still not motivation to push oneself against a clock, which is intrinsic. The reward here is food - extrinsic. That is the same as a cheetah going full speed to catch and antelope, but not going full speed (or even moving for that matter) just because you tell it that it could be the fastest of all time. The clock, and the meaning that it holds for us, is abstract and does not register in the heads of animals.