local extinction
ecological extinction
biological extinction
Endangered and threatened species are ecological somke alarms
endangered species
threatened species
tusk長牙,獠牙
Carolina parakeet卡羅來納鸚哥
flock群
forage搜索糧秣
butt煙蒂
Estimating extinction rates is not easy
mammal 哺乳動物
minor DNA copying mistake
正常情況物種可存活1百萬年到1千萬年才會滅絕
Human activities cause many premature extinctions
in due time在適當的時候
impoverish耗盡
extent程度;限度;範圍
persist持續;存留
colonization殖民地的開拓
speciation物種形成
weed雜草;野草
rodent齧齒目動物
