Population trends of native Hawaiian forest birds, 1976-2008: the data and statistical analyses

Author:

Camp, Richard J., Gorresen, Marcos, Pratt, Thane K., Woodworth, Bethaney L.

Title:

Population trends of native Hawaiian forest birds, 1976-2008: the data and statistical analyses

Periodical:

Hawaii Cooperative Studies Unit Technical Report

Year:

2009

Pages:

110

Subject:

Forest birds Birds populations Endangered species birds

Summary:

The Hawaii Forest Bird Interagency Database Project has produced a centralized database of forest bird survey data collected in Hawaii since the mid-1970s. The database contains over 1.1 million bird observation records of 90 species from almost 600 surveys on the main Hawaiian Islands—a dataset including nearly all surveys from that period. The primary objective has been to determine the status and trends of native Hawaiian forest birds derived from this comprehensive dataset. We generated species-specific density estimates from each survey and tested for changes in population densities over the longest possible temporal period. Although this cumulative data set seems enormous and represents the best available information on status of Hawaiian forest birds, detecting meaningful population distribution, density, and trends for forest birds in Hawaii has been difficult. These population parameters are best derived from long-term, large-scale, standardized monitoring programs. The basis for long-term population monitoring in Hawaii was established by the Hawaii Forest Bird Survey of 1976-1983 (Scott et al. 1986). Since then, however, only key areas have been resurveyed, primarily to monitor rare species. The majority of surveys since the early 1980s have been conducted by numerous, independent programs, resulting in some inconsistencies in methodology and sampling that in some cases has been intermittent and usually at limited scale (temporally or spatially). Thus, despite the consolidation of data into a centralized database, our understanding of population patterns is rather limited, especially at the regional and landscape scales. To rectify their deficiency, we present a frame work to improve the understanding of forest bird trends in Hawaii through an overarching monitoring design that allocates sampling at appropriate regional and temporal scales.

URL:

http://hilo.hawaii.edu/hcsu/documents/HCSU012CampetalPopulationtrendsofnativeHawaiianforestbirds1976-2008FINAL.pdf

Date:

November 2009

Collection:

Monographs