Hawaii’s renowned honeycreeper family, all closely related birds, have evolved into strikingly different species.  Likely their common ancestors were lone accidental arrivals to these isolated islands.  Over time, their offspring fitting into different physical habitat niches, favored those individuals whose physical variation gave them best survival ability.  Today, though genetically closely related, the honeycreepers physical shapes are as varied as woodpeckers and parrots on the mainland.  This iiwi (above) is well adapted to extract nectar from lobeliad type flowers. 

Protected by park managers from feral ungulates and predators, Haleakala is one of the very few last sanctuaries for these unusual and very rare native Hawaiian birds.

Links to Technical reports:

Haleakala N.P. Crater District Resources Basic Inventory:  Birds  (TR 26, Conant et al)

Evaluation of Rare and Endangered Bird Research Programs for Hawaii’s National Parks  (TR 23, Lamoureaux)

The Impacts of Malaria on Birds in Hawaii Volcanoes National Park  (TR 47, van Riper et al)

Ecology of Introduced Gamebirds in High-elevation Shrubland, Haleakala (TR 96, Cole et al)