That's because very large animals have a slow rateofreproduction, so all you have to do is remove a few young females from the herd, and you can, fairly quickly, significantly reduce the population.
那是因为大型生物的繁殖速度十分缓慢，所以只要除去象群中的几头年轻的母象，它们的数量就会大幅的下降。
2
The influence of guarding in the nest areas on the successful rateofreproduction;
巢区领域防御对繁殖成功率的影响；
3
Silkworm, Bpmbyx mori, an organism which can transform protein efficiently, has the advantages of short life circle, high rateofreproduction and mass raising and so on.