For the next three months, I’ll be living and working in the rainforest on Kaua’i, the northernmost of Hawai’i’s main islands.
The Hawaiian rainforest doesn’t look like what you think of when you hear either “Hawai’i” or “rainforest”. And though Kaua’i is called the Garden Isle, those lush vines and vibrantly-flowered trees you see around the coastal areas aren’t native to Hawai’i. In fact, apart from the tropicbirds that soar overheard, neither are the birds you regularly see. It’s surprisingly – and unjustly, when you think about it – hard to see what Hawai’i might have looked like pre-European contact.
Kaua’i’s remaining rainforest is restricted to the more mountainous, less accessible interior of the island, which is also one of the wettest places on earth. Even when the sun is out, it always seems to be misty; once your clothes are sodden there is little chance of them ever drying out. More often there is intermittent rain as the trade winds push clouds rapidly by. With the rains, streams ranging from the merest trickle to head-deep rise and fall, merge and split, later to spill into the muddy Waimea River. The terrain is rough: it’s a landscape of sharp ridges, steep-sided valleys, and waterfalls, many of them spectacularly high and narrow. The moisture supports a tapestry of mosses and lichens on the forest floor – except on the trail, which is knee-deep mud, and the occasional bog, which is waist-deep mud with some invasive grasses growing out of it.
Ohia lehua, a gnarled-looking tree with red shaving-brush flowers, dominates the forest- as it does in many other habitats in Hawai’i. The canopy is of uneven height, perhaps because much of the forest was flattened by a hurricane in 1992 – nowadays the surviving trees stand out above the rest of the forest. The understory in places is quite open, but usually it’s a jumble of fallen, moss-covered (and slippery) logs along with smaller trees and shrubs like the spiky pukiawe or the superficially poplar-like olapa and lapalapa. Ferns of many types grow everywhere, but uluhe is a notable hazard in places. It grows into unbelievably dense thickets that are impossible to bushwhack through, and stories abound of sharp broken fronds impaling people.
The forest is strangely empty. No large mammals live here except for (introduced, of course) rats and pigs. The latter make trails through the less steep parts and leave mud wallows in inconvenient places. Far enough into the forest, most of the birds are native – this is the last refuge for some of these species. But mejiro, or Japanese white-eye, are just as abundant, and the occasional shama or bush-warbler joins the chorus. Many of the native birds are surprisingly soft-spoken. Most often heard are the hiccough-y calls of apapane as they forage for ohia nectar, along with their wing-flutter as they travel through the canopy. Shorter, one- or two-note calls and longer trills of other species ring out; they all sound annoyingly similar and tend to imitate each other. Most distinct is the odd, squeaky-hinge sounds made by i’iwi, an iconic red-and-black Hawaiian bird with a large, downcurved pink bill. Still fairly common on the other main islands, it’s declining on Kaua’i for unknown reasons.
Many of these birds stay high up in the canopy, where they are backlit and hard to identify. But one, the elepaio – a distant relative of Eurasian robins – spends time in the understory and is easily spotted, as it’s extremely curious and a bit of a scold. It perches only a few feet away – I’m sure if I stood still for long enough one would land on my hand – and lets out a series of harsh chirps, or a wolf-whistle, or a strange up-and-down slide-whistle call. It only took about three days of field work before I started talking back to them.
All these birds, elepaio especially, are just beginning their breeding season. They forage in pairs and are beginning to build nests; eggs should be laid soon. My job is to locate and monitor as many of these nests as possible – with minimal disturbance, as all of these species are endangered (though not all are listed/protected). I’m lucky to be able to see all of Kaua’i’s extant native birds – indeed, its entire rainforest ecosystem – on a regular basis; most visitors to Hawai’i aren’t even aware of them. Over the next few months I’ll try to introduce some of these creatures to you.