Each animal has its ecological niche.是什么意思？

Each animal has its ecological niche.

每种动物都有自己的生态位。

each

adj. 每，各自的；pron. 每个，各自；

例句
They were completely absorbed in each other...
两人彼此倾心。

animal

n. 动物，兽，牲畜，<俚>家畜，牲口，<俚>畜生（一般的人），兽性；adj. 动物的，肉体的，肉欲的；

例句
Some animal and plant species cannot accommodate to the rapidly changing conditions...
某些种类的动植物不能适应迅速变化的环境。

has

v. 有( have的第三人称单数 )，（亲属关系中）接受，拿，买到；

例句
...the operation a patient has had.
病人做过的手术

its

pron. (it的所有格形式)它的，厥；

例句
The government is to accelerate its privatisation programme.
政府将加快其私有化计划的进程。

ecological

adj. 生态（学）的；

例句
...the site of the worst ecological disaster on earth.
世界上最严重的生态灾难发生地

niche

n. 壁龛，合适的位置（工作等），有利可图的缺口，商机；

例句
She has carved a niche for herself as a comic actor...
她作为喜剧演员已经闯出了一片天地。