Before Homo sapiens set foot in the Hawaiian Islands, birds ruled, filling grasslands, mountain tops, forests, shores, fulfilling roles of pollinators, fertilizers , scavangers, etc. Till man came bringing, from islands further east, pigs and goats and dogs (and later rats off the ships), the birds were safe and could evolve with their specific plants. Only turtles and bats competed for the space.
Later the white man came bringing the cattle, ten years after James Cook landed in Hawaii. In 1788 British Captain George Vancouver gave 6 cows and a bull to King Kamehameha, who protected them and let them roam wild. By the end of the 1800s, 25,000 wild cattle roamed the landscape.
But back to our poor birds. The first of course to disappear were the ground-nesters, as goats and pigs ran amok. Today most of the plants species survive but the birds continue to diminish decade by decade.
Top: Hawaiian Rail- found on the big island by early explorers, but extinct by 1890s,mainly due to cats, rats and dogs.
Bottom: Hawaiian O'o Bird. A beautiful thrush whose feathers were used by the ali'i (royalty) to make capes and feathered staffs. Europeans later captured them and put them into cages where they died after a few weeks due to disease caused by mosquitoes. Later, hunters pretty much finished them off and the last on was sighted in 1934.