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

Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
limited to hand-capture until the EPA granted certified pest-control operators an emergency
registration to hand-spray caffeine for control in limited situations (Kraus and Campbell 2002).
Currently, both chemical (citric acid) and nonchemical (hand-capture and hot shower) control
methods are available to the general public. Hydrated lime was previously used against the frogs;
however, as of April 2008, it is illegal to use hydrated lime to control coqui frogs in Hawai„i until the
EPA permit is renewed (http://www.ctahr.hawaii.edu/coqui/control.asp). Community interest in
coqui control remains high although public funding for local programs has been cut and/or
eliminated in recent years. The current tools and resources for controlling the coqui frog are not
sufficient to eradicate populations. New technology, such as thermal heat treatment units and new hot
water showers for nursery plants being shipped to the mainland are being developed (HISC 2007).
Jackson’s Chameleons (Chamaeleo jacksonii)
Jackson‟s chameleon was introduced to Hawai„i from East Africa in 1972. The current distribution is
from sea level- 2,000 ft on the main Hawaiian Islands. They prefer shrub or arboreal habitats with a
daytime temperature between 70-90°F and a nighttime temperature between 50-68°F. The initial law
that prohibited individuals from possessing Jackson‟s chameleons in Hawai„i was overturned in
1994. Jackson‟s chameleon is characterized by its ability to rapidly change color and pattern and its
long tongue that helps to capture prey. The sticky tip of the tongue can reach small invertebrates
(e.g., insects, spiders, and small snails) in 0.06 seconds (Waring 1997). Prey capture is facilitated by
independently rotating eyes. They average 10 in in total body length (Staples and Cowie 2001). The
reproductive capabilities of Jackson‟s chameleon contribute to its invasive potential. The average
clutch is 28.7 eggs and each female has a maximum of 5 clutches (Masurat and Masurat 1996).
Although the elevational range of this species is generally below the Refuge units, Jackson‟s
chameleons are known to occur at lower elevations below the KFU and could impact the forested
areas of both units as a result of global climate change. The Jackson‟s chameleon consumes both
native insects and bird eggs (Staples and Cowie 2002).
4.12.5 Introduced Arthropods
Invasive arthropods in Hawai„i include insects, spiders, mites, centipedes, and millipedes. An
estimated 20 arthropod species invade and establish themselves in the Hawaiian Islands each year
(Messing et al. 2007). Haines and Foote (2005) found that the abundance of invasive insects
decreased with increasing native insect diversity at the KFU.
Southern House Mosquitoes (Culex quinquefasciatus)
The southern house mosquito was introduced to the Hawaiian Islands around the 1820s and occurs
from sea level-4,921 ft on the Island of Hawai„i (Ahumada et al. 2004). Elevation plays a large role
in the population dynamics of mosquitos. At lower elevations, the southern house mosquito has been
found to occur in high numbers and populations consistent throughout the year. In contrast, mosquito
populations in middle and high elevation areas are relatively low and show biannual extremes; high
numbers occur from August-September and lower numbers occur between February-May (LaPointe
2000).
4-94 Chapter 4. Refuge Biology and Habitats