The Attack of the Killer Rhododendrons (15 page)

At an impressively long stretch of sand at Kekaha Beach Park, we drenched ourselves in sunblock in an attempt to return to winter as pale as when we left. The sand was a beautiful gold colour and completely unlittered by kelp or shells, suggesting to me that the waters around Kauai cannot be very productive. The beach was also almost completely unlittered by other people, surprising for a holiday Monday in February. The few that did join us were trying to boogie-board in the entirely underwhelming surf, or hanging out near their large-wheeled beach trucks. We spotted ‘A (a.k.a. Brown Boobies), Ae’o (Hawaiian Stilts), and K?lea (Pacific Golden Plovers). All were native.

In the evening, we drove to the moaning Spouting Horn blowhole. The area is built up with swank hotels and posh homes. Almost every tourist we came across was making a game of telling every other tourist that they would have had a much better experience if
they had arrived just ten minutes, ten days, or ten years earlier. A Minnesotan told anyone who would listen that the blowhole had been blowing much higher just ten minutes earlier. A lady from Texas claimed that the humpback whales had been far more numerous when she visited the previous year. We had a pretty good time of it despite being chronologically challenged. A cow humpback whale was demonstrating to her calf the best ways of showing off to a crowd, arcing out of the water, lying on her back, and slapping the water with her fins, and generally doing the hokey-pokey.

T
HE K?KE’E NATURAL HISTORY MUSEUM
isn’t an easy spot to get to, high on a narrow and tortured road along the Waimae Canyon. As we were on our way shortly after sunrise and most vacationers seem to enjoy a little lie-in, we had the road to ourselves. The route was punctuated with opportunities to pull off and see the canyon in all its glory. Mark Twain apparently described it as the “Grand Canyon of the Pacific.” It must be true, because the quote appears on more than 40,000 websites. Strangely, I cannot find a shred of evidence that Twain ever did describe the canyon that way. I’m not even sure that he ever visited the original Grand Canyon. I suppose the canyon is so jagged because it has never been blunted by glaciers. It is a valley of the gnarled digits of a very elderly woman crippled by arthritis. While I kept the Jeep from plunging into the canyon, Lisa spotted a Chuckar and two Erckel Francolins, introduced to Hawaii in 1923 and 1957, respectively.

We were met at the museum by Michelle Hookano. She seemed in particularly good spirits for someone who had just come from a staff meeting. Her raven hair spoke of Polynesian genes, but her blue eyes were so light it made me wonder if she saw the world differently than I did. She is involved in outdoor programs for youth and seemed to be the sort of person who would rather have children playing in the forest than playing video games.

The banana poka, the focus of our visit to Paradise, is one of roughly 600 plant species in the passion flower family. Passion flowers were given their genus name,
Passiflora,
because Spanish
explorers of the New World felt that their flowers had signs of the Passion of Christ. The banana poka is native to the cool, moist forests of the Andes in Venezuela, Peru, and Bolivia. At least twenty-five other
Passiflora
species are found in Hawaii. Most of these are under cultivation, but a dozen manage to persist without the help of humans.

The banana poka is a liana, a vine that makes its living by clambering over other plants; the “poka” part of its Hawaiian name refers to this inclination to climb. In South America, the species is comparatively rare, with insects and other pests consuming its flowers and fruits. In the absence of the predators, parasites, and disease that keep the banana poka populations in check at home, densities in Hawaii greatly exceed those in South America. In Hawaii, the banana poka is capable of growing so densely that it sometimes creates a curtain of vegetation, running roughshod over forests, pastures, and farmland. It can be so thick as to inhibit the germination and growth of native seedlings. By covering the host tree, banana poka plants decrease their host’s ability to photosynthesize, and compete with the tree for nutrients in the soil. In a storm, the banana poka can break its host’s branches or even topple the supporting tree. A perennial, individual banana pokas may persist for as long as twenty years.

The plant has a sneaky trick that makes it all the more noxious. Unlike many other plant species, an individual can fertilize itself, and so a single individual can found a population even in the absence of friends. The banana poka blooms throughout the year, its pink flowers hanging like medallions from the vine; it was introduced to Hawaii for its ornamental value. An oft-repeated story claims that the original introduction was made by someone trying to cover an unsightly outhouse, although the story may be apocryphal.

The plant was first introduced to the Pu’uwa’awa’a region of Hawaii in 1921. Another introduction came in 1928 in Honua’ula. Infestations spread so rapidly that they eventually coalesced into one continuous population.

The infestation of Kauai began in 1923. The plant now covers something like 520 square kilometres of Hawaii and Kauai, an area greater than the combined surfaces of the countries of Barbados and San Marino. Hawaii’s Department of Agriculture considers it to be a “Noxious Weed for Eradication or Control Purposes”; given all of the capital letters, it seems they take the plant rather seriously. Besides Hawaii, the banana poka has also been introduced to Mexico, South Africa, India, Sri Lanka, and New Zealand, although it is only in Hawaii that it has become a serious pest.

Given its name, it is not surprising that banana pokas produce edible, elongate yellow fruit. Each fruit contains as many as 200 seeds. The seeds have hard coats, allowing them to pass unharmed through the digestive system of the creature that eats them. Seeds are then deposited in a fertile situation. Feral pigs are the single most important dispersing agent, and the highest pig densities often correspond to the highest banana poka densities.

So what is to be done about the banana poka in Hawaii? Getting rid of the pigs would be a good start. Herbicides are often ineffective and can kill native plants in the community. Control is sometimes possible by chopping them down, which is notoriously labour-intensive for a plant that grows so quickly. Introducing pests from their South America home comes with the risk of damage to other desirable plant species, including the lillikoi, the purple passion fruit whose harvest constitutes a minor industry in Hawaii. To date, the greatest success with agents of biological control has been with a fungus,
Septoria passiflora,
which seems to work best in wetter areas.

Michelle pointed out another interesting biological control method. Some birds are nectar robbers. Birds had discovered the nectar reserves located at the base of the banana poka’s flowers, and by gaining access to the nectar by poking a hole in the flower, and therefore not fertilizing it, were keeping the plant from producing seeds. “The birds are nailing it,” she said.

Banana poka eradication efforts in Koke’e State Park have been so effective that when park personnel need to collect vines for the
Banana Poka Round-up, volunteers have to search backroads in four-wheel drive trucks. Luckily, Michelle spotted one of the vines draped over a tree in a nearby meadow.

However, other forces are continuing to spread the plant. When ripe fruit drops to the ground, pigs eat them, dispersing the seeds. Pigs didn’t swim to Hawaii, of course; they were brought by Polynesian settlers. These were followed by black-tailed deer and goats, which quickly proliferated and spread. All three mammals are hunted legally in Koke’e State Park. Michelle explained that pigs can be hunted throughout the year with dogs and knives. I thought I had misheard, and asked for clarification. She claimed that an Airedale–pit bull–Labrador retriever cross is trained to grab and hold the pig while the hunter runs up and kills it with a knife. Was she teasing me?

According to the Kauai telephone directory, she wasn’t. Wild pigs can be hunted with dogs and knives in, for instance, Hunting Unit C, year-round on Saturdays, Sundays, Mondays, and state holidays, at a rate of one pig per hunter per day. Hunting Unit C must really hate wild pigs, where they can also be dispatched with rifle, muzzleloader, handgun, bow and arrow, or sustained teasing.

I suppose I can see why locals are so eager to kill pigs, aside from the opportunity to eat their yummy, yummy bits. Pigs in Hawaii now number more than 100,000 individuals. They root in the soil for grubs and worms, leaving depressions that fill with rainwater and become breeding opportunities for mosquitoes. They eat the fruit of introduced plants like the banana poka and Brazilian strawberry guava, spreading their seeds.

Banana poka were not the only exotic plant species we spied growing around the museum’s buildings. Michelle pointed out Chinese fir, introduced around 1804. Hoop pines were brought from Australia around 1880. We saw loblolly pines, California redwoods, Monterey cypress, Italian cypress, Mexican cypress, and two species of eucalyptus.

After thanking Michelle for her time, there was nothing for it but a hike, and in all of Kauai, this was the place for it. Michelle
suggested that to see native birds the best spot was the Alaka’i swamp, the highest-elevation swamp in the world. We continued up to the end of the road and found the Pu’u o Kila Lookout. At more than 1,200 metres, looking out over the Kalalau Valley, it seemed that we had come to the end of the world. The swamp is the result of past volcanic indigestion and 350 days of rain a year. Even though we were fortunate to be visiting on one of the other fifteen days, the red mud trail was slick, preventing the vast majority of visitors to Pu’u o Kila from leaving the car park. A missed step put Lisa on her backside and covered our
Birds of Kauai
book, purchased thirty minutes earlier at the museum’s gift shop, in red slime.

Our perseverance was rewarded. We had left the mosquitoes below us and entered a fern-filled world of shade trees and mist. Verdant greenness was punctuated by the spiky red flowers of the ‘ohi’a lehua tree, whose nectar attracted wonderful feathered creatures. First came the ‘Apapane, a crimson-red honeycreeper whose black bill and red wings seemed a suitable costume for a superhero. Then we spied the ‘Anianiau, which seemed less like a bird and more like a flying lemon plugged into a car battery. The smallest of Hawaii’s honeycreepers, it is found only on Kauai, and generally only above 1,000 metres. A little deeper into the swamp, we spied the Kauai ‘Elepaio. I had read about the behaviour of this bird in scholarly papers and expected something a little showier from a native Hawaiian bird. They are grey and slightly darker grey, with bits of tan and two narrow grey bars on the wings, but they earn bonus points for being relatively common and carefree.

T
HIS LEFT US
with a glorious February day to play tourist. Rising very early, we took the Jeep to the region of Poipu, and bounced along rutted dirt cane-field roads to the last of the beaches, Mahaulepu. It was supposed to be one of the best places on the island to see endangered monk seals. We didn’t see any. Scrambling up and over rocks of solidified sand, we spotted a pod of thirty dolphins. Then we spied a group of whales bearing down on a school of large
fish, driving them up in the air in a mad attempt to avoid being breakfast. And then we spotted something almost as good as a monk seal—a green sea turtle, endangered in anyone’s book, lazily swimming by. Liberally slathered in sunblock, I dozed on the beach while Lisa watched the antics of humpbacks for nearly three hours. She also spotted a Wandering Tattler, known locally as the ‘?lili.

By the end of our brief stay in Hawaii, we had seen nine native bird species. Regrettably, we had chalked up a massive sixteen species of bird that been brought to Hawaii by humans. Most of the plants and insects and all of the reptiles we had seen were also introduced. It all got me thinking about the nature of Paradise. I had to wonder if Hawaii can be Paradise if it hosts so strong a military presence. Can an island be Paradise if its crime statistics look good only in comparison to other islands? Is it Paradise if the only major road is notoriously congested all day every day? Is this Paradise if the shark attack statistics are downplayed by claiming that most fatalities are those paddling surfboards? Hawaii certainly looked like Paradise when we were greeted home by a blizzard.

REASON NUMBER SEVEN FOR INTRODUCING A FOREIGN SPECIES: BECAUSE POOR PEOPLE WILL EAT ANYTHING, RIGHT?

I
F GOD WERE A FROG,
I suppose He might be a Paradise toad. The sort of creature that only a mother could love, this amphibian has warty red skin with patches of sickly green. Discovered by Harold Braack, whose surname sounds oddly like the call of a toad, it breeds in small spring-fed pools in arid rocky regions of western South Africa. There seems to be something particularly holy about both Mary’s frog, known only from Mount Balabag on the island of Palawan in western Philippines, and the Virgin Island coqui, found on the islands of Tortola and Virgin Gorda. Alternatively, the Almighty might be represented in amphibian form by the southern ghost frog. Found in forest streams of the Cape Mountains of South Africa, it has skin the colour of light brown sugar with splotches of slightly darker brown sugar. The bleeding toad sounds somehow biblical; its status of “critically endangered” wasn’t helped by the eruption of its favourite home, Mount Galunggung, in 1987. My favourite contender for an all-powerful frog is a globular little yellow mass with red and black spots known as the Holy Cross toad.

In contrast, there can be only one contender for Satan in the form of a frog. So foul and evil a creature that it appears on the
World Conservation Union’s list of 100 worst invasive alien species, the American bullfrog is a truly despicable creature when it is found in the wrong place.

The right place for an American bullfrog is eastern North America from Nova Scotia south to central Florida and northern Mexico. The wrong place is anywhere else, including China, Cuba, England, France, Israel, Japan, Russia, and nine countries in South America. Once established at a site, bullfrogs seem willing to expand their range rapidly along streams, canals, and irrigation ditches.