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

Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
contract for labor and equipment and to purchase herbicide to spray blackberry and other invasive
species. Backpack sprayers will be used to spray patches of blackberry scattered throughout the
forest. The contractor will also be asked to provide a tractor-mounted spray rig (with two spray
wands) for use on larger patches located in more accessible areas within the grasslands and upper
edge of the forest. The Refuge will direct the contractor where to spray, provide herbicide, provide
water at minimal distance to the operational area, and do everything possible to maximize efficiency.
Concurrently, Refuge staff will continue their blackberry control efforts (spray application of
herbicide, pig control and reforestation) at similar levels to those of the past few years. Outlying
blackberry colonies will receive highest priority for eradication. As the periphery is controlled, the
effort will constrict inward toward the core infestation, where blackberry patches reach their greatest
size and density.
Monitoring will consist of continuing annual weed and ungulate surveys on established transect lines.
Every fifth year a more intensive survey methodology will be applied to assess control efforts and
make adaptive adjustments to the control approach. Progress of the blackberry eradication effort will
be monitored though annual weed and ungulate surveys using established transect methods. Gross
changes in distribution and abundance will be monitored through collection of presence/absence and
density data within a contiguous series of 5 x 10 meter plots along the 17 transects. This will
maintain the continuous series of data collected annually since 1995 and sporadically before that
date. Continued funding for weed and ungulate surveys will be essential through the planning period,
beginning in FY2010 and beyond.
Six endangered bird species (‘akiapōlā’au, Hawai‘i ‘ākepa, Hawai‘i creeper, ‘io, nēnē, and koloa
maoli) the endangered ‘ōpe‘ape‘a, six endangered plant species, and the diverse assemblage of other
native plants and animals that inhabit the Refuge will all benefit from blackberry and other invasive
weed species control efforts. Endangered and native plants will experience reduced competition for
space, light and nutrients. Areas currently occupied by blackberry and other invasives will be
recolonized by native plants that provide food and habitat for the native animals and plants the
Refuge is mandated to protect. The absence of thorny blackberry thickets will facilitate fence
maintenance, tree planting efforts, and the ability of staff and visitors to walk and work in the forest.
The biodiversity and health of the native forest community will increase.
A weed control program will be established on the Kona Forest Unit to promote restoration of the
forest understory to benefit native wildlife species. Intensive weed monitoring and control efforts at
the Kona Forest Unit will require resources that are not currently available. It is hoped that during the
plan period resources can be obtained that will make the program viable on the Kona Unit modeled
loosely on what has been done at the Hakalau Unit (i.e., use of staff, partner and contractor resources
as available).
Cost Estimate: $150K annually, $200,000 every 5th year
H) Predator exclusionary fence for nēnē nesting at Hakalau Forest NWR
Nēnē at Hakalau Forest NWR thrive well, except during breeding when predation on nēnē goslings
by cats, mongooses, and possibly ‘io has been a problem. The current fences in the area are not
working well. The fences are outdated, too small, and do not prevent predation. A 15-acre fenced
exclosure will be built using predator proof fencing materials to reduce predation by terrestrial
predators. Reproductive success is measured each year at Hakalau Forest NWR, and comparisons
C-20 Appendix C. Plan Implementation