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

Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
Based on results of annual invasive species transect monitoring, control invasive plant species with
the goal of achieving reduced occurrence of invasive plants over 15-year plan period.
Conduct surveys for pest animals such as ungulates, nonnative mammalian predators, and cats and
dogs.
Control pest animals using appropriate IPM techniques including, but not limited to, trapping,
snares, and shooting (ground and aerial).
Inventory streams and stream corridors.
Rationale:
Streams cross through various habitat types, being intermittent at higher elevations, and perennial at
lower elevations. Some streams with steep walls protect endangered and native plants from grazing
by ungulates. Fauna within the streams and riparian areas at lower elevations are unstudied and
unknown. Although unstudied at higher elevations, the fauna is thought to be exclusively
invertebrate. Other species of conservation and management concern include native forest birds,
koloa maoli, and endangered plants.
Glacial meltwater created ravines during the Pleistocene era. Rainfall and runoff currently maintain
stream habitats.
Invasive gorse can degrade ecological integrity of stream corridors by displacing native riparian
vegetation communities and reducing surface water availability. Gorse seeds can wash downstream
from highly infested lands above the Refuge via stream corridors.
Ungulates and rats degrade water quality through soil disturbance and feces deposition. Lack of
groundwater retention due to upstream human disturbance (e.g., grazing, soil compaction) can lead
to flash floods. Streams also transport and disperse pest plant seeds.
Objective 4.2: Protect and maintain semipermanent natural ponds.
Protect and maintain semipermanent natural ponds for opportunistic breeding and loafing by koloa
maoli and migratory shorebirds, with the following attributes:
• Shallow, less than 4 ft, open water with shoreline emergent vegetation (e.g.; Carex);
• Presence of endemic invertebrates (e.g., damselflies and dragonflies);
• No nonnative mammalian predators (e.g., mongooses, rats); and
• No dogs and cats.
Strategies to achieve objective:
Maintain exterior management unit ungulate fencing (45 miles).
Conduct surveys for pest animals such as nonnative mammalian predators and cats and dogs.
Control pest animals using appropriate IPM techniques including, but not limited to, trapping,
snares, shooting, and rodenticide (aerial and bait stations).
Rationale:
All of the natural and manmade ponds are above the mosquito elevation so there is no concern
about these features providing potential mosquito breeding areas.
Previous ranching operations built and maintained ponds as a source of water for cattle. These
manmade ponds are used rarely by koloa maoli as nesting areas. Migratory birds occasionally use
Chapter 2. Refuge Management Direction 2-29