USGS Pacific Island Ecosystems Research Center
Welcome to PIERC
Research at the Pacific Island Ecosystems Research Center focuses on providing the scientific understanding and technologies needed to support and implement sound management and conservation of our Nation's biological resources occurring in Hawai'i and other Pacific island locations.
Spotlight on Research
Tools for Restoration
Exploring methods of invasive rat control in Hawaii Volcanoes National Park: Introduced rat species, including black rats, Norway rats, and Polynesian rats, have been blamed for the population decline of many native Hawaiian plant and animal species. Many methods have been tested in an attempt to control these invasive species in order to inform protected area land managers with the most cost effective method of suppression. Dr. David Foote recently published a technical report describing the use of poison bait to control invasive rodents in remote conservation areas. Poison bait was distributed by helicopter, a new method of bait dispersal. Using radio collars, researchers tracked rats following the bait drop and found that all collared rats in the treated area were dead within 9 days of bait application. Additionally, no predatory birds were found dead within 3 months of baiting. The results of this study indicate that aerial dispersal of poison bait could be an effective control method of invasive rodents, especially in remote, montane forests that are difficult to access. This study contributed to the EPA's understanding of poison bait as a control mechanism for rat populations in conservation areas. To learn more about how rats and other invasive species impact Hawaiian forests, click here.
Climate change and avian malaria present a dual threat to Hawaiian forest birds: Avian malaria limits the habitable range of many Hawaiian forest bird species. Birds have continued to move to higher elevation forests with temperatures too cold for mosquitoes. A recent study led by PIERC ecologist, Dr. Lucas Fortini, has used climate projection models to predict the geographic distribution of 10 Hawaiian forest bird species. Many species investigated are at the greatest risk of extinction: they have narrow geographic ranges and are endemic to a single island. Dr. Fortini, PIERC biologists Drs. Eben Paxton and Jim Jacobi and colleagues from Pacific Island Climate Change Cooperative and US Fish and Wildlife Service found that all 10 species are projected to lose at least 50% of their range by 2100. Additionally, 6 of the 10 species are projected to lose 90-100% of the geographic range. Although these projections are troubling, Fortini reiterates that there is hope for Hawaiian forest birds, "Our research, along with that from several fellow researchers, clearly shows what we can do to prevent projected impacts: if we deal with disease and mosquitoes, we can save these birds.” The article, titled "Large-Scale Range Collapse of Hawaiian Forest Birds under Climate Change and the Need 21st Century Conservation Options" was published in PLOS ONE and can be found here.
30-year study of land bird status on Rota, Mariana Islands, indicates widespread population decline: A research team led by the Hawaii Cooperative Studies Unit has found that 7 of the 11 land birds studied on the island of Rota, Mariana Islands, have experienced population declines since 1982. One species of particular concern is the critically endangered Mariana crow (pictured) which experienced drastic population declines from 1,400 birds in 1982 to less than 200 birds in 2012. Land birds face many threats including loss of habitat, tropical storms, and invasive predators including feral cats, monitor lizards, and rats. Continued inventory and monitoring of land birds on Rota will improve the ability to detect changes in the status and trends of species populations and allow managers to make conservation decisions. The paper, "Current land bird distribution and trends in population abundance between 1982 and 2012 on Rota, Mariana Islands" was published in the Journal of Fish and Wildlife Management.