Demography and Movements of the Endangered Akepa and Hawaii Creeper

Lowest rates of mortality and emigration occurred between May and August. Both species appeared to defend Type-B territories typical of cardueline finches, retained mates for more than one year, and showed strong philopatry. Home ranges for Hawaii Creepers ( x = 7.48 ha) were larger than those for Akepa (x = 3.94 ha).

No difference was found between home range sizes of males and females for either species. Geographic Description: Hawaii Creepers and Akepa were studied at four sites on the island of Hawaii. The Keauhou Ranch study area (19.50, 155.33; 1800 m elevation) had a discontinuous canopy dominated by ohia and naio (Myoporum sandwicense) and had a long history of grazing by cattle and logging for koa and ohia.

A 16-ha grid marked at 50-m intervals was established at this wet (ca 2000 mm annual rainfall) forest site. The 16-ha Kilauea Forest study area (19 .52, 155.32; 1600-1650 m) was in a relatively pristine, closed-canopy, wet forest dominated by 20-30m tall koa and 15-25 m tall ohia trees, and was approximately 1.8 km NW of the Keauhou Ranch study area. This site was described in detail by Mueller-Dombois et al. (1981)..

The 50-ha Hamakua study area near mor continuous canopy and an almost complete lack of native understory plants because of intensive grazing by cattle The 50-ha Kau Forest study area (19.22, 155.65; 1750 m) had a closed canopy of ohia and a largely ungrazed understory of kolea (Myrsine lessertiana), olapa (Cheirodendron trigynum), kawau (Ilex anomala), and native ferns. 1.5.2 Bounding Rectangle Coordinates Methodology: Estimated densities of Hawaii Creepers and Akepa at each of the four study areas by the variable circular-plot method (Reynolds et al. 1980, Ramsey and Scott 1979) during eight min count periods as described in Ralph (1981).