Hawaii Christmas Bird Count Data

More-recent trends in the occurrence of many bird species in Hawaii have been inferred by data collected during Christmas Bird Counts through 2007 (see Introduction for more information). Graphs have been prepared based on five Christmas Counts that have extended consistently for at least 20 consecutive years, at Kapa'a (1971-2007) and Lihue (1972-1992) on Kaua'i, at Waipi'o (1977-2007) and Honolulu (1944-2007) on O'ahu, and at Volcano (1972-2007) on Hawai'i Island. Species were selected based on observations of at least 70 individuals during at least 13 years of the count, and graphs were prepared for species of interest and those counts with trends or discenable cyclic patterns. Regressions were performed on number of birds observed per party hour against year, and significant trends (based on P < 0.05) are reported for species recorded throughout the time frame of the count.

The following table indicates selected species and provides links to graphs when created. In the table, "Increase" and "Decrease" indicate species that either have significant trends throughout the count period, or species with populations that either came into or became extirpated from, respectively, the count circle during the period. "Cyclic" indicates a species that shows apparent cycles, peaks, or periods of low numbers within the count timeframe but do not show significant overall linear trends. Links to graphs are provided for species with increasing, decreasing, and cyclic patterns. "No Trend" indicates stable or fluctuating numbers but no significant linear trend or apparent cyclic patterns; graphs were not created for most of these species.

Click on species name for pdf versions of species accounts.