04 May 2008


Our field trips aren’t always into the mountains. Over the past month much of our time was occupied by two trips to Lehua, one of Hawai‘i’s offshore islets. We're headed back this week...

The last surviving pair of Lehua rabbits can no longer be found in the wild. They were put into captivity as part of conservation efforts several years ago. In fact, the same conservation effort nearly wiped out the entire population, all except the two rabbits that will spend their remaining days in a wire hutch in my supervisor’s garage. While a sad story for the animals, it’s a happy one for Lehua, because the rabbits never belonged on Lehua in the first place.

the northwest tip of the islet

Lehua is the largest offshore islet in Hawai‘i. It is the remnant of an ancient volcanic crater now standing 2 miles across and 800 feet high that has slipped halfway into the sea, forming a north-facing crescent island. Lehua lies about 1/2 mile to the north of Ni‘ihau, the last inhabited island of the Hawaiian archipelago about 25 miles west of Kaua‘i. Ni‘ihau is privately owned by a ranching family and is forbidden except for the families of the 200 or so native Hawaiians that still live there. Lehua, however, is owned by the US Coast Guard who have been allowing biologists to study the plants and seabirds on the islet for years.

nw coast of ni‘ihau

sammy the monk seal

The only native animal inhabitants of Lehua are seabirds and Hawaiian monk seals. Rabbits made their debut over a hundred years ago with the foresight of hungry sailors. They reasoned it would be nice to have some game available on the islet in case of a shipwreck. Over the years the rabbits wrought havoc on Lehua’s already sparse vegetation. Recognizing the significance of Lehua as critical habitat for nesting seabirds, the Hawai‘i State Department of Fish and Wildlife had them eradicated about 2 years ago.

hauling gear through the boobies

Although the plants have been recovering since the rabbits’ removal, Lehua is currently dominated by nonnative grasses and shrubs. This is where the National Tropical Botanical Garden has stepped in. As part of a contract with Fish and Widlife, the Garden has outplanted several hundred native Hawaiian plants. The challenge however is that plants are very thirsty when they are trying to establish and as far as Hawaiian islands go, Lehua is extremely dry. Most of the plants are on an irrigation system, so the actual watering of the plants is fairly easy. The tricky part is getting the water to the island. There’s only two options for travel to Lehua: helicopter and tour boat. Being that helicopters cost $1,000 per hour and aren’t very seabird friendly, our boss has opted for the latter.

crew off-loading water jugs onto a surfboard

The tour boat companies have actually been giving biologists rides out to Lehua for years now. There’s no proper landing at the islet, only a couple reef shelfs on the south side so you’ve got to swim in from the boat with your bags and scramble ashore. Otherwise it’s a pretty plush trip. While onboard, you get to play tourist complete with complimentary breakfast, a cruise along the Na Pali coast and whales and dolphins galore. Then after spending a couple days camping on Lehua, there’s lunch and an open bar on the way back. A couple extra mouths to feed and a little show of the biologists landing for the tourists really isn’t a big deal.

Now imagine arriving at the dock at 5:45 AM and greeting your friendly crew with over 100 gallons of water weighing close to 900 lbs, in 5 gallon jugs to load onto the boat. Those biologists suddenly aren’t so cute anymore. But they tolerate us – especially with the heavy handed tip we provide on the way there and back. We help them load and unload the jugs from belowdeck and when we arrive at Lehua a crewmember uses a longboard to swim about 3 jugs at a time from the boat to shore. Its definitely a production but once on island, as I said, its pretty mellow. We use a portable 4 hp water pump to move the water from the shore up into the irrigation tank and aside from a few plants off the system it pretty much takes care of itself.

ridiculous red-footed booby

Exploring the island is fairly amazing, especially now during the seabird breeding season. The first sight to greet you are hundreds of red-footed boobies nesting in the shrubs and squawking in irritation as you pass. The slopes of the crater are also littered with the burrows of wedge-tailed shearwaters which makes walking anywhere on Lehua sometimes feel like a surgical procedure. Further upslope brown boobies nest on the ground and larger burrows are often occupied by red-tailed tropic birds. Over the ridge on the northern slope, the inner side of the crescent, are black-footed and laysan albatrosses cruising the tradewinds like small aircraft and already nursing chicks this time of year.

Back on the south side is base camp – a weatherport with cots and gas stove. The north shore of Ni‘ihau entices you from across the channel to the south with miles of empty, beautiful white sand beaches. And the humpback whales are all but gone now, migrating back towards the Arctic. But during both our Lehua trips in March and April, juveniles and mothers with their calves constantly cruised and breached all around the island.

base camp

condos for wedge-tailed shearwaters

Our first trip over Easter weekend consisted mainly of weeding, watering, and setting rat traps around the native plants. We also explored the Northwest crescent arm, collecting native plant seeds from the only area the rabbits didn’t reach. On our second trip just two weeks ago, Brenda Zahn, a bird biologist on Kaua‘i, accompanied us and we helped her band albatrosses and red-tailed tropicbirds. Pretty darn cute, those albatross chicks - especially when they start barfing fish oil all over you when you grab them for banding. Its gross and the poor guys are losing the lunch for which their parents have been scouring the seas all day. But the benefits outweigh hungry chicks and stinky field clothes - bird banding enables concrete measurements of breeding success and survival of threatened seabirds like the albatrosses nesting here.

a young whipper-snapper

Conservation efforts on Lehua – the banding, the revegetation, the rabbit removal – they’re all for the birds really. Albatross are hit hard by long-line fishing. Both they and the red-footed boobies nest in only three places on the main Hawaiian islands, and Lehua is the only place where they don’t have to contend with dogs and feral cats. Now that the Lehua rabbits are gone, slated next for eradication are the rats, known predators of seabird eggs. While few could argue against planting native vegetation, killing introduced animals is certainly more controversial, certainly the darker side of conservation.

Natalia and Brenda band another one

On the first day of the our most recent trip, we contour along the southern slope of the crater with Brenda to visit a colony of nesting cattle egrets in a kiawe tree. Another modern introduction to the Hawaiian Islands, egrets are also known predators of seabird chicks. Natalia and I came here on our last trip and threw the eggs to the fishes, but didn’t have the heart to do the same with the recently hatched chicks. With years of intimate work with her seabirds, Brenda has no qualms. The helpless chicks from three weeks ago are now running from us on two strong legs. I grab my first one and feel its heart beating in my palm.
“Cervical dislocation,” Brenda yells over to me as she demonstrates by yanking the head and neck of the egret chick in her hands. “This is brutal,” I say to myself.
I take another look at the red-foots nesting in the same tree as the egret colony. I’m here to help, right? Brenda’s onto her third victim already. Before a second thought arises, I yank the egret’s head. The beating heart stops and I throw the body to the sea. Plenty more chicks are scrambling through the kiawe bush. No rabbits, but more dirty work yet to be done.

black-footed albatross and landing gear

waiting for food
sammy's portrait shot

1 comment:

Anonymous said...

Clayton - you should submit this stuff to a magazine. It's an amazing story and you've got cool photos to go with it!