Translator Disclaimer
1 January 2002 SCALES OF FOOD AVAILABILITY FOR AN ENDANGERED INSECTIVORE, THE HAWAII AKEPA
Author Affiliations +
Abstract

The Hawaii Akepa (Loxops coccineus coccineus) is an endangered bird that has declined dramatically in the last 100 years, and is now rare or absent from many areas that appear to support suitable habitat. Food availability may play a role in these distribution patterns, but differences in food between sites may arise from different sources. I compared prey availability between a site supporting a large, stable Hawaii Akepa population, and a site from which Hawaii Akepa have declined in the last 100 years for unknown reasons. I used three spatial scales to compare food between sites to explore the basis of differences in food between sites. At a scale appropriate for comparing prey population dynamics (scale 1), I found that prey population densities are similar between sites, suggesting that introduced (or native) predators or parasitoids have not affected prey populations differently between sites. At two larger scales incorporating habitat structure, I found that food availability is much lower at the site of Hawaii Akepa declines. Differences in canopy density per square meter (scale 2), and in canopy cover per square kilometer (scale 3), result in lower food availability that may have effects on individual foraging birds as well as on potential Hawaii Akepa population density. These findings illustrate the importance of explicitly incorporating spatial scale into inquiries about food for Hawaii Akepa, and suggest that the site of population declines may not be suitable habitat with respect to food for this species.

J. Scott Fretz "SCALES OF FOOD AVAILABILITY FOR AN ENDANGERED INSECTIVORE, THE HAWAII AKEPA," The Auk 119(1), 166-174, (1 January 2002). https://doi.org/10.1642/0004-8038(2002)119[0166:SOFAFA]2.0.CO;2
Received: 23 March 2001; Accepted: 8 October 2001; Published: 1 January 2002
JOURNAL ARTICLE
9 PAGES


SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top