This is the so-called Alaka'i Swamp, actually a high-elevation bog. This area is home to two critically endangered birds, the Puaiohi and Akikiki. I saw a Puaiohi (Small Kauai Thrush, as opposed to the extinct Large Kauai Thrush) which only a few years ago was itself feared to be headed to extinction. Now, though still very low in numbers, they have made an amazing recovery, due in no small part to a re-stocking program by USFW to get birds back into areas they formerly frequented. This is one of the few happy stories about Hawaii's avifauna. The quiet, Nuthatch-like Akikiki was formerly much more common, but now is the toughest endemic to get, and is the one I missed.

The boardwalk in the photo is to protect the fragile ecosystem, and covers large sections of the bog.