Our Liviiif; Resources — Hawaii 



375 



Extinction 



The rate of extinction within Hawaii's 

 endemic birds is by far the highest in the United 

 States and is approached worldwide only with- 

 in a few other isolated island groups. At the time 

 of Captain Cook's visit in 1778 some 93 

 species and subspecies of native birds were 

 breeding in Hawaii, as determined by subse- 

 quent discovery and scientific description. In 

 the ensuing two centuries, at least 23 of these 

 have gone extinct (A. O.U. 1983) and another 13 

 are imperiled. Recent discoveries of the bones 

 of prehistorically vanished species now reveal a 

 vast anay of former birds that became extinct 

 long before Captain Cook arrived. Thirty-five of 

 these have already been scientifically described 

 (Olson and James 1991) and must represent 

 only a small fraction of the fonns of birds that 

 existed prehistorically in Hawaii. 



Extinctions over the past 200 years (Fig. 5) 

 show a disproportionate number of bird species 

 vanishing during the 1890's, a decade conclud- 

 ing a period of intense discovery and collecting 

 of Hawaii's birds. A similar large decline in the 

 1980's represents nine forms not reported since 

 then. Ralph and van Riper ( 1985) discussed the 

 factors that have contributed to the decline in 

 Hawaiian bird populations since the arrival of 

 the Polynesians. 



Aliens 



An early listing of the alien species in Hawaii 

 was that of Caum (1933), who identified 92 

 species as alien introductions. These may be cat- 

 egorized as established, not established, or uncer- 

 tain. Most (75%) of the alien species established 

 in 1933 are still present (Pyle 1992). Few of those 

 deemed uncertain or not established in 1933 have 

 persisted until today. Introductions continued 

 during the I940's and 1950's but thereafter were 

 severely curtailed by stronger governmental 

 restrictions on importation of wild birds. Of the 

 54 alien species considered established in Hawaii 

 today, 31 (57%) had been introduced more than 

 60 years ago, and 23 (43%) have been introduced 

 and have become established since 1933. 



Conclusion 



Hawaii's birds comprise four groups: native 

 and alien resident species, and breeding and 

 nonbreeding visitor species. Factors affecting 

 population levels differ markedly among the 

 groups. Although current status of species with- 

 in all groups is fairly well understood, assessing 



meaningful trends for species is difficult for 

 lack of comparable quantitative data on 

 statewide populations over time. 



References 



A. O.U. 1983. Check-list of North American birds. 6th ed. 

 [with supplements through 1993]. American 

 Ornithologists Union. Washington, DC. 877 pp. 



Caum, E.L. 1933. The exotic birds of Hawaii. B.P. Bishop 

 Museum Occasional Papers 10(9). Honolulu, HI. 



Ellis, S.. C. Kuehler. R. Lacy. K. Hughes, and U.S. Seal. 

 1993. Hawaiian forest birds conservation and assessment 

 management plan. Final report. Captive Breeding 

 Specialist Group, lUCN. Apple Valley, MN. 142 pp. 



Engilis, A., and T.K. Pratt. 1993. Status and population 

 trends of Hawaii's native waterbirds. Wilson Bull. 

 105:142-158. 



Harrison, C.S. 1990. Seabirds of Hawaii — natural history 

 and conservation. Cornell University Press, Ithaca, NY. 

 249 pp. 



Johnson, O.W.. PM. Johnson, and PL. Bruner. 1981. 

 Wintering behavior and site-faithfulness of golden 

 plovers on Oahu. 'Elepaio 41:123-130. 



Kirch. P. 1982. The impact of the prehistoric Polynesians on 

 the Hawaiian ecosystem. Pacific Science 36:1-14. 



Olson, S.L., and H.F. James. 1991. Descriptions of thirty- 

 two new species of birds from the Hawaiian Islands. 

 Ornithological Monographs 45 and 46. American 

 Ornithologists Union. Washington, DC. 



Pyle. R.L. 1992. Checklist of the birds of Hawaii— 1992. 

 •Elepaio 52(8):53-62. 



Ralph, C.J., and C. van Riper 111. 1985. Historical and cul- 

 tural factors affecting Hawaiian native birds. Pages 43-70 

 in S.A. Temple, ed. Bird conservation 2. University of 

 Wisconsin Press, Madison. 



Scott, J.M., C.B. Kepler, C. van Riper III. and S.I. Fefer. 

 1988. Conservation of Hawaii's vanishing avifauna. 

 Bioscience 38(4):238-253. 



Scott. J.M.. S. Mountainspring. F.L. Ramsey, and C.B. 

 Kepler. 1986. Forest bird communities of the Hawaiian 

 Islands. Studies in Avian Biology 9, Cooper 

 Ornithological Society, Lawrence, KS. 431 pp. 



Shallenberger. R.J., and G.K. Vaughn. 1978. Avifaunal sur- 

 vey in the central Ko'olau Range, O'ahu. Ahuimanu 

 Productions, Honolulu. 106 pp. 



Fig. 5. Extinction of native breed- 

 ing birds since 1778. Steps mark 

 the decade of the last record for 

 each form considered extinct 

 (A.O.U. 1983). The 70 forms 

 shown as currently existing 

 include 13 in peril, with steps 

 marking the decades of their last 

 known records. Yellow represents 

 prehistoric forms. 



For further information: 



Robert L. Pyle 



Bishop Museum 



Department of Natural Sciences 



741 N. KalaheoAve. 



Kailua. HI 96734 



