Japanese white-eye in Hawaii

In many cases coevolution is derived from competition in which both species vie for an edge or advantage to maximize their dietary or "resource" acquirement.

[1] The force of natural selection has promoted the dietary or "resource" specialization of many of the later stage endemic species – a prime example being the honeycreeper.

[5] In contrast, the white-eye maintains a highly diverse selection of dietary options (including nectar)[5] and is able to take full advantage of numerous habitats on the islands.

The differences in resource limitations between the two species has resulted in the drastic decline of the honeycreeper population, as they are outcompeted by the invasive white-eye.

Increases in the Japanese white-eye population in Hawaii have negative effects on the growth and survival of native birds in the community.

These birds also showed shorter tarsi, the group of bones in the hind feet of some vertebrates, although this change was less drastic than that seen with the bills.

Birds with original bill lengths closest to that of the white-eye suffered the most, undergoing changes that lowered their foraging efficiency.

Also, this replacement could lead to differing levels of outcrossing compared to those resulting from visits by the native species of birds.