With reference to ratttlesnake round ups its a fact the numbers are not as many as in the "good old days" and the sizes are on the whole are smaller. If hunters keep taking the large animals out it will take years for them to recover in these areas so you see smaller and smaller animals being taken until there is not much left to hunt and the hunters have to move to new hunting grounds.
Within the last few years the number of large trophy animals such as deer taken annually is greater that ever. Many of these are taken in areas where they were once hunted close to eradication or where they didn't even inhabit years ago. This is due to modern hunters being selective and harvesting animals that have reached maturity and only taking the amount of animals the population can handle. In Wisconsin the average age of bucks taken during bow and gun seasons both has increased over the last few years. This shows that responsible hunters and a good system of hunting seasons and regulations is achieving their goals. Many fishermen now practice catch and release making the average size of fish caught, along with numbers of fish caught increasing. In the U.S. one of the main reasons we have animals to hunt/fish at all is because of hunters and their support of game regulations and the maintaining of habitat. Their desire to always have the opportunity to hunt/fish for them and their children/grandchildren is very important. This is the real obsession of the majority of hunters here. Very few of us here hunt to survive. Might be a reason game management and the impact on animal size and populations may differ from here and Peru.