Final Comprehensive Conservation Plan - U.S. Fish and Wildlife ...

Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
process/the Forest Bird Workshop (USFWS 2008) and continues in published literature (Camp et. al
2010, Freed 2010, etc.). The Service expects to support appropriate studies in the future as needed to
address these issues (see Appendix C).
4.4.3 Hawai‘i Creeper (Oreomystis mana)
The Hawai„i creeper is a small, inconspicuous Hawaiian honeycreeper. Adult males and females are
predominately olive-green above, dull buff below, and have a dark gray mask extending around the
eyes; males are brighter. Their similarity to Hawai„i „amakihi, Hawai„i „ākepa, and introduced
Japanese white-eyes complicates field identification.
Hawai„i creeper are endemic to the Island of Hawai„i. In the 1890s, Hawai„i creepers were found in
„ōhi„a and „ōhi„a/koa forests throughout the Island of Hawai„i, usually above 3,600 ft elevation.
Hawai„i creepers were recorded in the Kona and Ka„ū districts as well as the forests above Hilo.
They were noted to be very abundant and generally distributed but had some unexplainable gaps in
their distribution, especially at lower elevations. In general, the Hawai„i creeper‟s decline was not
well documented, perhaps in part due to difficulties of field identification. However, a drastic decline
in numbers in Hawai„i Volcanoes National Park during the 1930s and 1940s was noted, and the
species had virtually disappeared from the Park by about 1960 (USFWS 2006b).
As of 1979, the Hawai„i creeper was confined to four disjunct populations in wet and mesic forests,
primarily above 5,000 ft. Two populations near Kona totaled only about 300 birds with the number
of birds in central Kona estimated at 75 birds. A third subpopulation near Ka„ū consisted of about
2,100 birds. The largest subpopulation is found on the Hāmākua coast on the windward side of
Mauna Kea, where 10,000 ± 1,200 (95 percent CI) birds reside (Scott et al. 1986). Recent surveys
suggest that the population estimate may be higher. A population recorded on Kohala Mountain in
1972 could not be relocated during the Hawai„i Forest Bird Survey in the early 1980s (Scott et al.
1986).
It is estimated that slightly more than 17,800 ( 221 SE) Hawai„i creepers occur in the North
Hāmākua study area (Camp et al. 2003). The HFU currently protects 49 percent of the Hawai„i
creeper population in the study area (approximately 8,700). Positive trends in Hawai„i creeper
density were observed for the 24-year (1977-2000) and 14-year (1987-2000) study periods. The
mean density of creepers was 0.11 birds per acre (SD = 0.97) in 1977, and 0.51 birds per acre (SD =
2.44) from 1987-2000.
The Hawai„i creeper is found in the montane wet „ōhi„a, mesic koa/„ōhi„a forest and montane dry
koa/„ōhi„a/māmane forest at the HFU. Densities of Hawai„i creeper are highest in upper elevation,
high-stature „ōhi„a forest. The species is absent or occurred at low densities in grasslands, in
heterogeneous habitats along the grass-forest interface, and in mid-elevation wet forest.
Surveys as recent as 2006 detected the Hawai„i creeper in the KFU (USFWS 2008). However,
population or density estimates have not been documented.
Hawai„i creeper occur most commonly in mesic and wet forests dominated by „ōhi„a and koa with a
subcanopy of „ōlapa, pūkiawe, „ōhelo, „ākala, kōlea, kāwa„u, and hāpu„u (USFWS 2006b). Outside
the breeding season, the species frequently joins mixed-species foraging flocks (Hart and Freed
4-24 Chapter 4. Refuge Biology and Habitats