Demography and Movements of the Endangered Akepa and Hawaii Creeper

Populations of the endangered Akepa (Loxops coccineus coccineus) and Hawaii
Creeper (Oreomystis mana) at four sites on the island of Hawaii. Mean monthly
density (+/-) of Akepa was 5.74 +/- 0.87, 1.35 +/-0.41, 0.96 +/- 0.13, and 0.76
+/- 0.12 Akepa/ha at Kau Forest, Hamakua, Keauhou Ranch, and Kilauea Forest
study areas, respectively. Hawaii creepers were found at densities of 1.68 +/-
0.53, 1.79 +/- 0.42, 0.48 +/- 0.06, and 0.54 +/- 0.08 birds /ha, respectively ,
at the four study areas. Highest capture rates and numbers of birds counted
from stations occurred from August through November and February through March.
Hatching-year birds were captured from May through December for Akepa and
April through December for Hawaii Creeper. Annual survival for adults at
Keauhou Ranch was 0.70 +/- 0.27 SE fro 61 Akepa and 0.73 +/- 0.12 SE for 49
Hawaii Creepers. 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).