Hawaiian Honeycreepers: Family Drepanididae

Honeycreepers are a family of finch-like birds native to the islands of Hawaii. This family takes on a diverse set of colors, from black and white, to red yellow, green, blue, orange and grey. Some species in this family have long curved bills, some with short, stout bills. Many members of this family build large cup shaped nests high in the trees, made from surrounding vegetation and lined with soft moss.

Like the tanagers of the Galapagos, a finch-like ancestor to the Hawaiian Honeycreepers colonized the islands of Hawaii and subsequently evolved and radiated to fill specific niches on the islands, based on various food resources.

Empty Niche-rs

An ecological niche is a specific way that one organism lives and survives in their habitat. For example, a woodpecker's "niche" is to find insects in wood by banging their head into a tree. Woodpeckers don't find too much competition from other species in this niche, and so generally thrive in their habitat. They have evolved and are specially adapted to that niche in order to best take advantage of it.

When organisms colonize an island for the first time, they will often find niches not yet exploited by another species, and so are able to evolve quickly to better adapt to that niche. In their old, mainland home, these organisms would have been restricted by competition with other species for food, and so evolutionarily they were more or less stuck in one form. Once they colonize an island and find they are able to exploit any niche they want, they are able evolve by natural selection to better access their new food resource. This is called adaptive radiation

Hawaiian Honeycreepers evolved from a member of the Fringillid (Finch) family, to exploit empty niches on the Hawaiian Islands. Many Honeycreepers are granivorous (seed eaters), like their finch ancestors, and have short, stout beaks to crack seeds. Other species have longer sharper beaks, and have evolved to eat insects. Others have very long, curved beaks to eat nectar. Another has taken on a crossed bill form, where the beak crosses at the tip to open up bunches of leaves and eat the insects living inside!

Unique Problems

While adaptive radiation produces very unique, interesting forms, these species normally run into problems when it comes to change. Honeycreepers evolved without many predators, so when the native Polynesians arrived with new invasive species, like rats, the honeycreepers suffered because they were not adapted to deal with foreign predators. Things continue to get worse for the honeycreepers, their habitat is being turned into farmland, and invasive species continue to kill them off. As of right now, 11 species of Honeycreepers have gone extinct and 14 more are considered critically endangered or endangered, because of human interactions.

Taxonomy

This family is often included as a sub-family within the Finch family, but can also be considered a separate taxa. There are currently 12 genera and 21 species. Genera include:

Genus Hemignathus
Genus Himatione
Genus Loxops
Genus Melamprosops
Genus Oreomystis
Genus Palmeria
Genus Paroreomyza
Genus Pseudonestor
Genus Psittirostra
Genus Telespiza
Genus Loxioides
Genus Vestiaria