有一个著名的例子:1870年,在美国开巴高原467km~2土地范围内,生活着4000头鹿,同时也有少量的美洲狮和狼在此活动。人们为了繁殖更多的鹿,便开始捕杀狮和狼,到1921年,这两种肉食动物几乎绝迹,鹿群迅速繁殖到10头,可是经过两个冬天,鹿群减少到60000头,到1939年,只剩下10000头…… 在没有了天敌狮和狼的情况下,鹿群为什么还会减少呢?大自然 There is a famous example: In 1870, within the 467km~2 land area of ​​the Kaba Plateau in the United States, 4,000 deer were living, and a small number of puma and wolf were also active here. In order to breed more deer, people began to kill lions and wolves. By 1921, these two kinds of carnivorous animals were almost extinct, and the deer population rapidly expanded to 10, but after two winters, the deer population was reduced to 60,000 to 1939. In the year, there are only 10,000 heads... Why did the deer get reduced without the natural enemies, lions, and wolves?