Alien Plant and Animal Species in Haleakala National Park
A Conversation with Lloyd Loope
From the Environmental Review Newsletter Volume One Number Five, May 1994
When non-native plants and animals are introduced into an island ecosystem they pose a serious threat to native species. Because of the isolation from the mainland, the warm climate, the fertile soils and abundant rain in the Hawaiian Islands, several thousand species of plants and animals evolved that exist nowhere else on earth. We discuss with Lloyd Loope, a park biologist, how alien species threaten native species on Maui and what can be done to manage them.
ER: Dr. Loope what is your academic training?
LL: I got my Ph.D.in Botany from Duke University specializing in plant ecology. Shortly after I finished I got a job with the National Park Service as a biologist and worked for the National Park Service for twenty-four years, the last thirteen years in Maui. I call myself a conservation biologist. My job in the park is to gather information on the biological systems necessary to manage the park. The job involves two facets: carrying out applied research which will assist protection of the native biological diversity of the park (and also to some extent of the Hawaiian islands) and to serve as advisor to the park superintendent on how to deal with management issues. Most of our research is on what effects alien species have on the natives species and deciding what to do about it.
ER: Do you work with animals as well as plants?
LL: Yes. I think it's important to give you an overview of what park management is doing. The control of alien plants is a relatively small part of the total effort. Most of the effort has gone into controlling two species of animals in the park: feral goats and feral pigs. These two animals have done the most damage to the park over the last hundred years.
There are two major national parks in Hawaii, Haleakala and Hawaii National Volcanoes. Hawaii Volcanoes is much bigger in area. They were the first parks to get rid of the goats. Our present superintendent, Don Reeser, was Chief of Resource Management of Hawaii Volcanoes National Park in the 1970s when they got rid of most of the goats. I think the attitude twenty-five years ago was that endemic plants and animals are interesting, but we're going to lose them and there's nothing we can do about it. In Hawaii Volcanoes National Park they built an exclosure to keep out goats and the next year a new plant species was discovered inside the fence. It presumably survived for decades as seeds in the soil. That really positive event started things moving in the right direction. Eventually goats were eliminated from both parks. [An edemic species exists only in a particular place. ed.]
ER: Have you got the goats out of Haleakala?
LL: There are a few left. We have radio collared Judas goats. Whenever a goat gets through the fence and into the crater it usually associates with these goats that have radio collars. Rangers fly over in a helicopter and shoot them.
ER: What do goats damage in the park?
LL: Goats have completely wiped out native vegetation in some areas. There are tree species in the Park that haven't reproduced for a hundred years because of the goats. [Goats eat the seedlings. ed.] In the mid 1980s that started to change because of a large project costing millions of dollars. The project involved fencing the Park and removing the animals. For feral goats that was accomplished by about 1987, and for feral pigs the project is ongoing. There are fenced areas within the Park where there are virtually no pigs. Fencing may seem like a stupid way to go about this but it's the only way we've figured out that works. It requires long term maintenance of the fences and we'll probably never be able to say we've got rid of all the goats because there will always be holes in the fences after a storm or an earthquake etc. So we're locked into this situation of maintaining the fences to keep the animals out. It'll take a lot the time, energy and money of the park management.
ER: Do goats and pigs affect some plants more than others?
LL: They affect virtually all plant species in the Park and indirectly, the insects and birds associated with those plants. The pig influence is almost everywhere in the Park. Incidentally, that influence is very recent. The first pig was seen in Haleakala crater in 1936. There were areas in Haleakala Park when I came here in 1980 that didn't show pig damage, but later suffered severe damage. That pigs are a relatively recent phenomenon is a surprise to many people. There's skepticism about this because everyone knows that the Polynesians brought pigs to the islands, but the Polynesian pig was smaller and for some reason it apparently didn't spread into remote areas of the forest. That's anecdotal information, but the fact that plant species such as lobelias, that are adversely affected by pigs, were still abundant in native forests through the early decades of this century indicates that pigs have not been in there long.
ER: Do pigs have any predators besides people?
LL: No, but it's a rough environment. The high elevation rain forest is wet and cold. It took pigs a while to get there. One possible reason is that there was not enough protein in the native forest for the pigs to feralize. Earthworms were introduced, probably carried in pig digestive tracts, and investigators have found that earthworms are an important food source for pigs. Earthworms have gotten almost everywhere in the park; occasionally in remote montane bogs you'll see large concentrations of earthworms forced to the surface by moisture. Earthworms seem to be what the pigs are going after when they dig up the forest floor.
ER: Earthworms are not native to Hawaii and they are not usually considered a pest.
LL: Right. This is a good example of one alien species facilitating the spread of another, like pigs spreading strawberry guava.
ER: Why are non-native species (plants or animals) such a problem on an island like Maui when they are not a threat on the mainland?
LL: That isn't fully understood, but island plants and animals evolved in isolation from the mainland. They didn't face the pressure of organisms and forces which are commonplace on the mainland such as frequent fire, and the trampling and browsing of ungulates. The only native mammals in Hawaii are one bat and the monk seal. There were no ungulates. The Hawaiian plants have never been subjected to grazing animals and it was devastating. Native Hawaiian plants are not adapted to disturbance and these weedy introduced alien plants are often able to compete for disturbed sites much better than the natives.
ER: So when disturbance occurs native plants lose ground to the introduced species?
LL: Exactly. On the U.S. mainland in many national parks fire plays an important natural role. In Hawaii there were occasional fires, but now when there's a fire it wipes out native plants and allows aliens to advance. In the Hawaiian parks the conditions are so changed because of introduced grasses that we do the best we can to put the fire out because fire generally favors the alien grasses.
ER: Why is it so important to preserve plant and animal native species in Hawaii?
LL: It's a matter preserving a meaningful sample of the biological diversity of the Hawaiian islands. What good is it? Native species have an enormous inherent value which some people recognize and some people don't. These organisms have evolved in isolation for as much as fifty million years. And if understanding the process of evolution is important, Hawaii is one of the best places in the world for studying evolution.
ER: How many endemic species are there now?
LL: Within the park? There are about 350 native species of vascular plants, of which around eighty-five per-cent are endemic to the Hawaiian islands. For flowering plants, ninety-five per-cent are endemic. But ferns are only about fifty per-cent endemic. Of the 350 native vascular species about 100 are ferns. The ferns are one of the first things to suffer from the pigs. The pigs destroy the cover of mosses and ferns on the forest floor. Once the pigs are gone it takes quite a while for the forest floor to recover. Speaking about the various groups, insects are the largest group of organisms in the Hawaiian islands. Probably between 6,000 and 10,000 native species in the Hawaiian islands and in the park something like a thousand species. There are a lot of introduced insect species of course, but of the native insects probably ninety-nine per-cent are endemic to the Hawaiian islands. As far as island endemism of the flowering plants, probably twenty per-cent of Maui's flowering plants are endemic to the island. With insects its even higher, over fifty per-cent of the native insects are endemic to this island. It is not a large biota but it has very high endemism. So that if species are lost on Maui, it's very likely they're gone. From our knowledge of the park, there are at least seven species of flowering plant that have become extinct within historical times and about eighteen others that have been extirpated, that exist outside the park, but not in the park. There's the opportunity in the future for re-introducing some of the extirpated plants. The first step was to get rid of the feral animals. We are in no great hurry to start enhancing the native plant systems because some species can recover quite well on their own. Others will need help. For example we had this plant in the citrus family, Zanthoxylum kauaense, which is not on any endangered list but we doubt if it's common anywhere. It occurs on other islands but on Maui there are probably no more than a half dozen surviving plants - only one in the park. My colleague Art Medeiros was giving a presentation to visiting politicians and in stressing the desperate conservation situation, mentioned that one of the park's tree species was down to the last individual and that someone had conveyed the information that it was dead or near-dead. Our Park Superintendent was horrified and suggested that something be done. So Art went out there the next week - it's a full day's trip in a four wheel drive vehicle - to check on this tree, and it was still alive but just barely. He collected some material for tissue culture at the Lyon Arboretum on Oahu. We're hoping that we can preserve that species through re-introduction of some individuals into the park.
ER: So biotechnology is one of your restoration tools.
LL: There are techniques available that would be wonderful for conservation. It will be expensive. It takes a lot of time and effort just collecting these plants. You have to pack them in dry ice to keep them cool to send them to Oahu. Art collected two specimens and by the time they got to the Lyon Arboretum one had mold growing all over it.
There are well over a hundred plant species listed federally as endangered in the Hawaiian islands. Soon there are going to be nearly 300. On Maui we will soon have nearly 100 plant species. For each one of these species recovery plans are being developed. I saw one plan the other day where it was estimated that over a fifteen year period it was going to cost a million dollars for one species. That's probably a reasonable estimate but where's that money going to come from? So far, almost nothing has been spent on the recovery of endangered plant species in the United States. They're listing and starting to prepare recovery plans but as far as real work, very little has been done. Certainly the technology is there to do it. It's a question of priorities and of funding. Of course we all know the nation has a budget deficit. It's a big problem. How are endangered species going to compete against health care?
ER: On the mainland many species are declining because we've eliminated or altered their habitat. Is the mission of Haleakala National Park to act as a refuge?
LL: I think that's true. To a certain extent existing reserves like the park could serve as Noah's arks for species that are in trouble. It needs to be done in conjunction with other agencies. There are other preserves managed by the Nature Conservancy and the State of Hawaii in the vicinity and with a strategic, expanded system of reserves I would advocate trying to save clusters of species within reserves rather than pouring money into species that occur in habitats that have been essentially destroyed and that occur in isolation from other species. There has to be an application unfortunately, of the concept of triage: some species probably don't need much help, other species may be hopeless, but let's concentrate on the species we have a chance of saving.
ER: Another restoration tool is gap analysis, which was started in Hawaii.
LL: Dr. Michael Scott at the Fish and Wildlife Service in Moscow Idaho, was a pioneer of this. When he worked in Hawaii back in the 1970s and early 1980s, they mapped the distribution of the most endangered honey-creeper species - a group of birds that is one of the best examples of adaptive radiation. [Adaptive radiation describes how organisms evolve to take advantage of unexploited territory or conditions. ed.]
ER: They're a spectacular bird.
LL: They're wonderful. There are a few species that are fairly common but there are quite a few species of honey-creeper that are very rare and many of them have become extinct or are in the process of becoming extinct. Mike Scott developed a map of the Big Island showing where the reserves were and where the very rare honeycreepers were, and there was little or no co-incidence. That doesn't mean that Hawaiian Volcanoes National Park is not of great value to biological conservation because it does a great job of protecting rare plants and invertebrates. In fact if you did gap analysis throughout the Hawaiian Islands you would probably conclude that the Kipahulu Valley in Haleakala National Park would be one of the most important places to protect. An expedition sponsored by the Nature Conservancy went in there in 1967 and later recommended that Kipahulu is an essential area to protect. It still is and it was added to the Park in 1969, with land donated by the State of Hawaii.
ER: What part of the park is Kipahulu?
LL: Haleakala National Park is only forty-four square miles. It's a wedge of about fifteen miles long and three miles wide, going from the summit of the volcano at 10,000 feet down to sea level and about half of that area is Haleakala crater which is relatively barren - what we call the aeolian zone where there is very little vegetation. But there are locally endemic organisms which thrive in this area. The Haleakala silversword is a good example. Then there's the shrubland and grassland, so open vegetation makes up about half the park. And the other half of the park is rain forest. Kipahulu Valley is the heart of the rain forest. It's closed to the public as a scientific reserve. The original rationale was that the Park Service didn't want anybody in there because this is one of the most important places in Hawaii to preserve and the best way to do that is to keep people out. After about ten years researchers went in there because of rumors that there were problems and found feral pigs had spread throughout the Kipahulu Valley. The Park Service learned you can't protect an area just by keeping people out. You have to watch out for alien species in an island situation. In the last ten or fifteen years scientists and managers have been the only ones to go into the valley - and not a lot of those. Most of their effort was in putting in fences and pig removal. We also have vegetation plots to monitor the recovery of vegetation.
ER: You were able to clear that area of pigs?
LL: A research program in the mid 1980s put in well over a thousand snares. And they researched the pigs to death. About the time the fencing was completed, researchers were going in there for two weeks at a time, three times a year for two years. They removed about 150 pigs. In at least the upper part of the valley there weren't any pigs left after the researchers got finished. So using that method its very feasible to get rid of pigs. The park's position is we don't think this is a wonderfully humane method but it's the only effective method we have. In fact very few pigs are suffering, now that their numbers are low. The most inhumane thing to do in our view is to have to be killing large numbers of pigs perpetually. And hunting with dogs is not humane either. But both hunters and animal rights groups have voiced strong opposition recently to pig control programs in Hawaii. This has resulted in a serious setback to state programs aimed a protection of native biota.
ER: I'm sure hunters wind up wounding and maiming as well.
LL: As a practical matter it's not really feasible to get hunters into a remote place like Kipahulu Valley without doing severe damage to the valley and losing hunters and dogs. Hunting doesn't work in this situation. There are and will always be lots of other places on Maui for pig hunting. And regarding animal rights, I personally feel we hold the ethical high ground. Don't the native plants and animals have rights too?
My job and the park's job is to protect biological diversity. I think that there are a lot of conservationists out there that support what we are doing. Unfortunately the state government doesn't hear too much from them.
Another area of real importance is trying to stop new alien species from establishing in the islands. Our research groups dabbled at this for several years with plants - instead of waiting until species come right up to the park boundaries. We've gone outside the park and found small infestations of new weeds and tried to eradicate them. We try to get other agencies interested in them. We feel we have to be proactive.
We have an interagency weed management group on Maui that meets six or eight times a year. We are trying to contain Miconia calvescens, a tree in the Melastome family, native to middle-elevation rainforests of Central and south america. Miconia has taken over Tahiti, an island which very closely resembles Maui in its climate and soils. Introduced to Tahiti in 1937, dense thickets of Miconia had replaced the native forest over most of the island by the 1980s, with dramatic reduction of biological diversity. This species is well established on a small area of Maui near the coast, where it has been spreading undetected for twenty years. Several agencies, including State Forestry, are now trying to stop the spread of this plant before it reaches the reserves. This type of cooperation is the only way we can deal with many of these alien species problems.
Copyright 1994 Environmental Review