marcusjb: You probably know this and did this, but if you have a wounded animal it is a good idea to give them some time before you follow up the trail -- maybe an hour in a case such as yours (bow hunting a hit, but the animal is observed to move on out of the area). Like others, I don't think you should have given up on the trail after 1.5 hours of tracking. I have tracked blood sign from a deer wounded by a friend for substantially longer than 1.5 hours before.