Answered by biologists.
The whole principle of carrying capacity is that if you let animals flood their environment they are subject to diseases, shortage of food, and starvation in the winter months. The trapping principle is that in the fall of the year, when the population is at its highest, you remove some individuals. In doing this, you remove the competition of food, you remove the severity of winter on the individuals that are left, and their reproductive rates are great They are in good shape in the Spring (as opposed to when they are overpopulated) and the population bounces back. You have a sustainable population rather than a boom and a bust, and that is the purpose of wildlife management.
Trapping today is a strictly regulated activity. Trapping practices are controlled by laws that ensure strict animal-welfare standards as defined by veterinary pathologists. We have humane standards and certified traps. Most animals are now captured in lethal traps that can kill virtually instantly. Larger predators are taken in modified live restraint traps that generally cause few injuries. Only a few furbearing species are still captured with modified restraining or cage traps, which have been shown to cause few or no injuries.
Answer by :
Paul Tufts, Wildlife biologist (retired) and trapper
Biologist, Association of Fish and Wildlife Agencies (Missouri, USA)