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

Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
of size range 0.6-0.89 in (Belwood and Fullard 1984, Fullard 2001). Prey is located using
echolocation. Water courses and edges (e.g., coastlines and forest/pasture boundaries) appear to be
important foraging areas. In addition, the species is attracted to insects that congregate near lights.
They begin foraging either just before or after sunset depending on the time of year; altitude also may
affect these patterns (USFWS 1998c, Mitchell et al. 2005).
It is suspected that breeding primarily occurs between September-December. Typically, two young
are birthed in May or June. Breeding has only been documented on the islands of Hawai„i and Kaua„i
(Baldwin 1950, Kepler and Scott 1990, Menard 2001).
Within the HFU, „ōpe„ape„a are found at Pua „Ākala, Maulua, and Upper Maulua Pond. Bats have
been observed and/or heard year-round along roads, forest clearings, and within koa/„ōhi„a mixed
montane mesic forests. Detections have occurred at elevations between 5,250-6,230 ft. Echolocation
data show that the HFU is an important foraging site for the „ōpe„ape„a (Menard 2001, Bonaccorso
2008). „Ōpe„ape„a have been seen within the KFU, though little is known about their foraging or
roosting habits there (USFWS 2008).
The availability of roosting sites is believed to be a major limitation in many bat species, but other
possible threats to the „ōpe„ape„a include pesticides (either directly or by impacting prey species),
predation, alteration of prey availability due to the introduction of nonnative insects, and roost
disturbance. Management of the „ōpe„ape„a is also limited by a lack of information on key roosting
and foraging areas, food habits, seasonal movements and reliable population estimates (USFWS
1998bc).
4.8 Native Hawaiian Invertebrates
Invertebrates are composed of a variety of groups including snails (Gastropoda) and various insects
such as beetles (Coleoptera), true bugs (Heteroptera), and moths/butterflies (Lepidoptera). Over
5,000 endemic insect species occur in Hawai„i (Howarth et al. 2003), of which beetles and flies are
the most specious (Goldsmith 2007).
Hawaiian invertebrates play an important role in native ecosystems. Invertebrate populations serve as
critical food resources for „ōpe„ape„a and native Hawaiian birds and therefore limit the populations
and distributions of these species (Howarth et al. 2003). Invertebrates are also essential pollinators
and detritivores (Gambino and Loope 1992).
Native Hawaiian invertebrates found during surveys of the Refuge units are listed in Tables 4-2, 3,
and 4. Due to the diversity of invertebrate species, expansive area of the Refuge units, and limitations
of baiting techniques, numerous additional invertebrates species may be present on the units.
Several federally listed endangered invertebrate species, including three endangered picture-wing
flies, occur on the Island of Hawai„i and within the Refuge units (Howarth et al. 2003, Haines and
Foote 2005). The Blackburn‟s sphinx moth (Manduca blackburni), an endangered arthropod that
occurs on Hawai„i Island, is not expected to occur at the HFU (Howarth et al. 2003) and has not been
observed on the KFU.
Chapter 4. Refuge Biology and Habitats 4-45