A new approach for analyzing bird densities from variable circular-plot counts

Author:

Fancy, Steven G.

Title:

A new approach for analyzing bird densities from variable circular-plot counts

Periodical:

Pacific Science

Year:

1997

Volume:

51

Pages:

107-114

Subject:

Bird populations Palila Loxioides bailleui Mamane Sophora chrysophylla Kanakaleonui Endangered species birds

Summary:

When estimating the size and trend of forest bird populations, a method called Variable Circular-Plot (VCP) counts, also known as variable area surveys or point transects, are used. In Hawaii, management decisions that may determine where and how species are saved from extinction are based on results of VCP counts as precipitous terrain and dense vegetation make it impractical or impossible to use line transects or other methods. As a result, a new approach for analyzing VCP count data that make it possible to adjust for various factors that affect detection distances such as observer, weather, time of day, and vegetation type that affect detection distances while maintaining adequate sample size, is described in this paper that uses coefficients that are calculated by multiple linear regression. The method was validated in two field studies where the density of birds could be determined by independent methods. Computer software for entering and analyzing data by this method is also described.

Label:

Birds - General

URL:

http://hdl.handle.net/10125/3100

Date:

1997

Collection:

Periodicals