 |
|
|
||||
| Biological Resources of the Pacific Islands |
|
| Home Page / Welcome Message / Mission Statement / PIERC Research Projects / Education Outreach / Publications Database |
 |
 |
 |
THE HAWAII FOREST BIRD |
 |
 |
Richard J. Camp, Bethany L. Woodworth Thane K. Pratt, Chris Collins and Heather Howitt. USGS-BRD, PIERC, Kilauea Field Station, Hawaii National Park, Hawaii |
| INTRODUCTION In 1976-1983, the U.S. Fish and Wildlife Service (now USGS-Biological Resources Division) conducted systematic surveys of forest birds and plant communities as part of the Hawaii Forest Bird Surveys (HFBS) (Scott et al. 1986) (Fig. 1). Results of this effort have proven to be an important conservation tool during the past two decades, but population estimates and range maps are now out of date. We present a comprehensive inventory of all forest bird census data collected over the last 25 years in a centralized, standardized, relational database (Table 1). |  |
CONTRIBUTORS The following supporters have generously contributed data or financial support: National Park Service; USFWS-Refuges & Ecological Services; USGS-Biological Resources Division; Hawaii Department of Land and Natural Resources; Kamehameha Schools; The Nature Conservancy; and private contractors. |
 |
 |
| DATABASE APPLICATION Spring survey efforts show that Iiwi (Vestiaria coccinea) distribution and abundance have decreased in the Hilo and Puna districts between the HFBS (late 1970s) and Subsequent Surveys (1986-2000) (Table 2) (Fig. 1c). Occurrences of Iiwi were infrequent below 1,300 m (4,200 ft) during both survey periods, although more so during the Subsequent Surveys. Efforts in the East Rift Zone and Puna - Geothermal area in 1992-1994 (Fig. 1c; lower right) yielded a 64% reduction in Iiwi frequency. Relative abundance decreased more than 35% between the two survey periods. However, neither reduction was significant at the 0.10 level due to extreme rarity of detections overall (n = 2 in Iiwi Subsequent Surveys). |  Changes in the frequency and relative abundance of Iiwi were similarly striking in the Hamakua and National Park regions (Fig. 1c; upper and left portions). Iiwi frequency decreased 54% since the HFBS surveys (Chi-square = 45.89, P < 0.0001). A decrease in relative abundance of more than 61% was observed over the same period. This application exemplifies quantitative information for an individual species; thus the database is a useful tool for resource managers. |
OBJECTIVES
|
METHODS
The database was created in MS ACCESS, and original survey data was contributed by cooperating agencies and individuals throughout Hawaii. Updated population estimates for native and alien Hawaiian forest birds will be produced using the most recent methodology (Buckland et al. 1993, Fancy 1997). Maps of transect locations and bird distributions are produced as GIS coverages using ARCINFO/ARCVIEW software. PROJECT STATUS As of August 2000, 151 surveys (82%) had been entered into the database. From 1976-2000, 13,575 stations on 425 transects have been sampled at least once. Seventy bird species have been recorded, including 31 native (26 forest species) and 39 alien birds. Of these, 44 species may be analyzed via the variable-circular plot method (21 native species), while 26 are best analyzed with other methods (10 native species). All regions of the main Hawaiian Islands have been infrequently or partially sampled, except see Table 1. The Kohala region, Hawaii, and Lanai have never been resurveyed, whereas Kauai, Molokai, West Maui, and the Puna region, Hawaii have received limited resurvey efforts. The Hamakua region of the Big Island has received extensive survey effort, spanning all but 5 years in a 24-year period. However, only a small portion of the entire Hamakua region has been sampled subsequent to HFBS (Figs. 1b and 1c). Therefore, caution should be used in interpreting trends in bird populations. |
| REFERENCES Buckland, S.T., D.R. Anderson, K.P. Burnham, and J.L. Laake. 1993. Distance sampling: Estimating abundance of biological populations. Chapman & Hall, New York. Fancy, S.G. 1997. A new approach for analyzing bird densities from variable circular-plot counts. Pacific Science 51:107-114. Scott, J.M., S. Mountainspring, F.L. Ramsey, and C.B. Kepler. 1986. Forest bird communities of the Hawaiian Islands: Their dynamics, ecology, and conservation. Studies in Avian Biology 9:1-431. Bird art: H. D. Pratt, Louisiana State University Museum of Zoology |  Fig. 1c. Example of the Database application. Iiwi distribution in the Hamakua, Kau and Puna regions of the island of Hawaii. |
  |
| AccessibilityFOIAPrivacyPolicies and Notices | |
 |
|