 |
 |
|
Abstract for the poster presented at the 2003 Society for Conservation Biology meetings Spatial habitat modeling of Hawaiian forest bird densities for estimation of population size and distribution. P. Marcos Gorresen, Richard J. Camp, Bethany L. Woodworth, and Thane K. Pratt. USGS Pacific Island Ecosystem Research Center, P.O. Box 44, Hawaii National Park, HI 96718. Accurate information on population size is fundamental for conservation biology. To these ends, the Hawaii Forest Bird Interagency Database Project has developed a GIS-intensive revision and update of population estimates and distribution maps for the Hawaiian forest avifauna. The project has produced a relational database of all forest bird survey data collected in the state since the mid-1970s. We used GIS to integrate information on species densities at surveyed locations with habitat data derived from remote sensing and field sampling, and to develop predictive models at the landscape level. The models used an autoregressive method that incorporates a spatially autocorrelated error structure, thereby accounting for fine-scale autocorrelation in density and habitat variables. Coarse-scale autocorrelation was controlled with trend surface terms. Densities were predicted for all 1-hectare cells within a study area, and totaled to estimate population size. We analyzed data from 65 variable circular plot surveys within a 64,843-hectare study area on the northeastern slopes of the Island of Hawaii that encompasses the Hakalau Forest National Wildlife Refuge. Results are presented for 3 native (Hawaii Amakihi [Hemignathus virens], Hawaii Creeper [Oreomystis mana], and Akepa [Loxops coccineus]) and 1 alien (Japanese White-eye [Zosterops japonicus]) bird species. Density surface maps based on models that incorporate habitat characteristics more accurately depict the relationships of bird density and habitat than inter- and extrapolation of survey site data alone. Species-habitat models provide an effective method for determining distribution and population size information essential for monitoring programs and conservation efforts. |
| Link to poster. |
|
Department of the Interior |
| Pacific Island Ecosystems Research Center 3190 Maile Way, St John Hall, Room 408 Honolulu, (Oahu) HI 96822 Phone: (808) 956-5668 |
This page maintained by: Hawaii Forest Bird Interagency Database Project Kilauea Field Station Building 344, PO Box 44 Hawaii National Park, HI 96818 Phone: (808) 967-7396 ext 252 |
|