Why did the bird species meet their demise?

Why did the bird species meet their demise?

Maori hunters exterminated at least ten species of moa. Many other bird species met their demise because of the rats （kiore） that arrived with the early Maori settlers. The rats spread out rapidly, devouring the eggs of birds, lizards, and other animals. The pace of extinction picked up in the 19th century, when Europeans introduced their own voracious rats, cats, stoats, and other predators.