Evolution, Ecology, Conservation, and Management of Hawaiian birds: A Vanishing Avifauna.—J. M. Scott, S. Conant, and C. van Riper III, Eds. 2001. Studies in Avian Biology no. 22. Cooper Ornithological Society, Allen Press Inc., Lawrence, Kansas. 428 pp., 35 contributed papers, overall introduction plus introductions to each of 6 sections, 3 color plates, 14 drawings, numerous tables, figures, and maps. ISBN: 1-891276-25-5 (cloth) $48.50; ISBN: 1-891276-18-2 (paper) $29.00, includes postage and handling.—Every biologist interested in Hawaiian birds will want to own a copy of this book. It reviews major areas of the state of knowledge of Hawaiian birds at the end of the twentieth century, summarizes the results of older studies, and reports the results of previously unpublished work. Most of the papers were delivered at a symposium of the Cooper Ornithological Society in Hilo in April of 1997. Here they have been expanded and supplemented with eight additional papers. The book is dedicated to Dean Amadon, Paul H. Baldwin, and David Woodside, whose work on Hawaiian birds beginning in the 1930s laid the foundation for the recent renaissance of studies reported here. Excellent drawings by Douglas Pratt and Patrick Ching make the book more attractive. The introduction contains a full checklist of the status of all resident, breeding, and visiting birds recorded on the islands and lists which residents are endangered (or threatened) and which are alien. The large body of published literature on Hawaiian birds is presented as a composite literature-cited section at the end of the book.
Douglas Pratt's striking frontispiece painting of the descending flight of the extinct Hawai'i Oo (Moho nobilis) says without words what the rest of the book says in great detail. The birds of the Hawaiian Islands, the most isolated archipelago in the world, provide exceptional case histories of dispersal and evolution of new species where geographic distributions and population sizes are necessarily limited. Unfortunately the birds of the Hawaiian Islands also provide examples of the various ways that human activities can cause extinctions. Alien species now outnumber native species in most lowland habitats. The fascinating story of the Hawaiian avifauna is actually a tragedy because, even with the increased conservation actions of recent years, extinctions of native birds continue. With the possible exception of the Hawaiian Goose or Nene (Branta sandvicensis), none of the 29 native Hawaiian birds on the federal list of threatened and endangered species is increasing in number. In fact, after an intensive search from 1994 to 1996 for 13 forest species now on the list, Reynolds and Snetsinger concluded that six of them are probably extinct. Several more probably cannot be saved because they are so rare. In their chapter on limiting factors, van Riper and Scott show that even in cases in which we are confident that we know the causes of population declines and recovery seems feasible, current actions are not commensurate with the scale and complexity of the problems. Clearly research alone will not solve the problem. The voting public will have to demand that more resources be devoted to conservation. The Hawaiian avifauna's current situation has evolved into an additional lesson: that land management is driven more by social and political forces than by scientific understanding. In the final chapter of the book, Steiner addresses the urgent need for a public education program that could in turn produce more government support for conservation, especially at the state level, not only to prevent those further extinctions that are not inevitable, but to guard against the future establishment of even more potentially damaging alien animals and plants.
The editors point out in the introduction that the current status of Hawaii's birds can not be fully understood without the perspective of the fossil record. When the birds known only as fossils are added to those with historic records, the total comes to 109 species unique to the islands. Many of those became extinct during the period of Polynesian occupation, from approximately the sixth to the eighteenth centuries, including honeycreepers, a honeyeater, owls, hawks, large-billed finches, and flightless geese, rails, and ibises. Additional extinctions after European contact in 1778 have reduced the native avifauna to at most 35 species.
The first section of the book, “Historical Perspectives,” contains two analytical papers. Curnutt and Pimm estimate the number of rails, parrots, pigeons, and doves that may have once occurred in the entire central Pacific region. Moulton and coauthors summarize published records of the 140 attempted introductions of nonindigenous birds to Hawaii. They find that success rates for columbiforms are related to the history of previous introductions elsewhere, that introduction effort matters for galliforms, and that the successful establishments of passeriforms are related to the sizes of their geographic ranges elsewhere.
In the introduction to the second section, “Systematics,” Helen James estimates that only 20 colonizing species were the original sources of the endemic avifauna. Their establishment led to radiations of rails, thrushes, honeyeaters, owls, crows, ibises and waterfowl, and some single differentiated species, as well as to the well-known radiation of the drepanidines (Hawaiian finches or honeycreepers). The survivors consist of various passerines, a hawk, a goose, an owl, and some small waterbirds, most of which are currently threatened with extinction or endangered.
Fleischer and McIntosh present phylogenetic relationships based on molecular data for extant Hawaiian taxa and their potential Old World and New World mainland relatives. They find evidence that the closest relatives of about half of the Hawaiian lineages are most closely related to North American taxa. They estimate that the evolution of the Hawaiian endemics has occurred within the last 5 million years, more recently than previous estimates, approximately the age of the current set of main islands. In a separate paper, Fleischer and coworkers report that the Po-ouli (Melamprosops phaeosoma), discovered in 1973 on Maui, is in fact a honeycreeper, albeit quite distinct from others. Rhymer finds that the Laysan Duck (Anas laysanensis) is more distinct genetically from the Hawaiian Duck or Kaloa Maoli (A. wyvilliana) and the Mallard (A. platyrhynchos) than the latter two are from each other. Pratt and Pratt do not trust phylogenies based on molecular or cranial osteological data. They prefer the biological species concept to the phylogenetic species concept for the construction of phylogenies. In a separate paper, H. Douglas Pratt, whose results differ from those of other workers, offers his phylogenetic analysis for drepanidines, based entirely on phenotypic characters. The current AOU Check-List follows an earlier analysis by Pratt.
In the section on “Status and Trends,” Ainley and coauthors describe a 17 year program of banding fledgling Townsend's Shearwaters (Puffinus auricularis newelli) attracted to lights on Kauai. They use a Leslie matrix model to compare the demographic importances of different sources of mortality and conclude that reduced lighting and more predator control in breeding areas will be required to stabilize the population. Udvardy and Engilis use banding recoveries from the holarctic Northern Pintail (Anas acuta) to show its widespread wintering distribution on many islands in the Pacific Ocean, as well as in Hawaii. After having reviewed the results of the Hawaiian Forest Bird Surveys of the 1970s and 1980s, plus the reports of Banko in the 1980s, Reynolds and Snetsinger designed the Hawaii Rare Bird Search, a two-year concerted attempt to search previous sites in remote areas of four major islands for the 13 rarest Hawaiian forest birds. Six were not found at all, but one undetected species (Olomao [Myadestes lanaiensis]) may persist in an area to which they could not get access. Baker's intensive search on Maui for the Poouli located only three individuals in 1997.
Sheila Conant introduces the ecology section with a history of the extensive studies and surveys sponsored by the U.S. Forest Service, U.S. Fish and Wildlife Service, and Hawaii Department of Land and Natural Resources. The seven excellent papers in that section address subjects like responses of particular species to variation in food availability, habitat characteristics, the importance of cavities in large old trees to the endangered Hawai'i Akepa (Loxops coccineus coccineus). Clever comparisons of demographic and fitness characters of two populations of that species that differ in population density allow Hart to conclude that the differences are not due to external threats like disease or predation.
Van Riper and Scott begin the next section with a summary of the history of the six most frequently cited environmental factors limiting bird populations on the islands: (1) habitat changes, (2) human predation (hunting), (3) predation by introduced predators, (4) avian competition, (5) avian parasites and diseases, and (6) abiotic factors (e.g. hurricanes). Of those factors, the one for which they find the least evidence as a limiting factor is interspecific competition, although alien species clearly serve as reservoirs for diseases that kill native species. The major habitat changes occurred in the past, but alien herbivores continue to destroy native vegetation. Today predation and habitat modification by introduced species at all elevations and disease below 1,200 m dominate interpretations of limiting factors. Avian malaria (Plasmodium relictum) and avian pox virus (Poxvirus avium), carried among birds by an introduced mosquito (Culex cinquefasciatus) that is elevation limited, continue to decimate bird populations. The need is urgent for additional reserves at high elevations on Maui and Hawaii. In those areas, and at other special sites, control of feral cattle (Bos taurus), pigs (Sus scrofa), goats (Capra hircus), rats (Rattus spp.), feral dogs (Canis familiaris), and the small Indian mongoose (Herpestes auropunctatus) will be necessary. Feral cats (Felis catus) must be controlled at seabird colonies. Jarvi and coauthors summarize the evidence that the major declines in honeycreepers below 1,200 m in elevation in the last 100 years were due to disease and that, at some low-elevation locations, natural selection for less virulent strains of the diseases is occurring. Shehata and coauthors used DNA-based diagnostics as well as blood smears to estimate malarial prevalence in birds in urban Honolulu and found that one honeycreeper, the Oahu Amakihi (Hemignathus flavus), seems to have evolved genetic resistance to malaria. Fancy and Snetsinger remind the reader that factors other than disease and predation should still be considered. Loope and coauthors warn that current measures to prevent the establishment of additional alien species are far from adequate.
The sixth and final section of the book contains a fine chapter by Banko and coauthors that summarizes the history of recovery and management efforts and current recovery strategies. Three famous examples of efforts to save single species are the cases of the Hawaiian Goose or Nene, Hawaiian Crow or ‘Alala (Corvus hawaiiensis), and the Palila (Loxoides bailleui). Kuehler and coauthors describe the cooperative efforts since 1993 of The Peregrine Fund, the U.S. Fish and Wildlife Service, and the ‘Alala Partnership to implement intensive restoration techniques for particular species at two captive propagation facilities. Their “rear and release” strategy involves collection of eggs from the wild, artificial incubation and hand-rearing of chicks, and release to the wild. Examples of programs for management of entire communities are the Hakalau Forest National Wildlife Refuge on Hawaii and the Haleakala National Park on Maui. About $1 million per year are currently going into the research and management of Hawaiian birds. That may sound like a lot, but the state of Hawaii contributes an estimated one-half of one percent of its state budget. Steiner (p. 382) says that “federal management funds for which the state could compete if it had matching dollars go begging or go elsewhere.” This book documents that research on Hawaiian birds is currently at the forefront of paleontology, evolutionary biology, ecology, genetics, epidemiology, and conservation biology. The next step is to get the management up to that same level of excellence.
