Ecology of Invasive Species

Early detection of invasive species can enable their successful eradication. With climate change and dynamic patterns of global trade, it is difficult to predict which new invasive species will next get introduced and where introduction and establishment will occur. We are analyzing where non-native species have first established in Hawai‘i to develop mapped predictions of the relative risk of new...

Climate change and invasive species are transforming ecosystems. The Resist-Accept-Direct (RAD) framework organizes management objectives into those that seek to Resist change and maintain historical ecological communities, those that Accept some or all aspects of ecological transformation, and those that Direct an ecological community to a preferred state. We are evaluating risks posed by climate...

We are using environmental DNA samples to assess habitat occupancy of the invasive southern house mosquito in Kīpahulu Valley, Maui. An understanding of mosquito distribution is critical to developing and implementing tools to prevent the transmission of avian malaria, a primary threat to Hawaiian forest birds.

We are sequencing the DNA of Wolbachia bacteria found in mosquito populations in Hawai’i and those used for mosquito control. We are also developing sample processing techniques to increase the efficiency and accuracy of monitoring mosquito control efforts to help long-term survival and restoration of Hawaiian forest bird populations.

We are combining high-resolution spatial imagery with ground-collected data to create detailed classification maps of native and non-native plants on Lāna‘i. We are also using the high-resolution maps, historical satellite and aerial imagery to analyze changes in ‘ua‘u - Hawaiian petrel - nesting habitat. For the first time at island scales in Hawai’i, this species-level mapping uses high...

Introduced rats are notorious predators of birds and their nests worldwide, but especially on remote islands. Rats ( Rattus exulans ) first arrived in Hawai‘i with Polynesian colonists about 1,000 years ago, resulting in deleterious consequences for native birds and ecosystems. Since Western contact in 1778, two additional rat species have become established in Hawai‘i, including the highly...

Hawai‘i's precipitation is greatest in upland areas that are typically forested. This precipitation provides water for both people and ecosystems. Precipitation can either run off and contribute to streamflow, or infiltrate into the ground and provide water for plants, base flow to streams, or recharge to aquifers. The exact routing that water takes is controlled by many factors, including the...

Rapid ‘Ōhi‘a Death (ROD) is an emerging and rapidly spreading disease of ‘ōhi‘a ( Metrosideros polymorpha ), a keystone native forest tree in the Hawaiian Islands. The disease is highly pathogenic in native ‘ōhi‘a and can lead to significant mortality once symptoms become evident. This emerging pathogen is a significant threat to native forests throughout the state because of its potential impacts...

Small mammals (including three species of rats and one species of mongoose) and social Hymenoptera (order of insects including ants and yellowjacket wasps) form two groups of alien predators in Hawaiian ecosystems. The combined impact of these predators has resulted in substantial loss or reduction of native biota in the Pacific. Furthermore, given the past successes of managing or excluding feral...

Feral pigs ( Sus scrofa ) have been identified as a significant problem in 120 U.S. National Wildlife Refuges. Pigs cause substantial degradation to natural ecosystems through rooting, digging, and browsing, but they are particularly destructive in Hawai‘I, which has no native terrestrial large mammals.

Islands and atolls throughout the Pacific have been impacted by invasive ant species. Threatening native ants and other arthropods with their aggressive behavior and ability to colonize large geographic areas, invasive ants pose one of the most serious threats to island ecosystems. This project focuses on three areas of the Pacific: American Samoa, Rose Atoll, and Johnston Atoll.

Six species of biting mosquitoes have been introduced to the Hawaiian Islands since Western contact, two of which are vectors of dengue, chikungunya, and Zika viruses. Environmental conditions favorable for the transmission of dengue and Zika occur year-long across Hawai‘i’s coastline. To better understand the ecology of vector mosquitoes and support public health efforts, mosquito monitoring at...