Hawaii Field Station Records --

The Bureau of Biological Survey (BBS) Control Methods Research Laboratory in Denver first established a rodent control field station in Honolulu in 1935 to help limit economic losses to the island’s sugarcane industry. The research station was funded by taxes collected on Hawaiian-grown sugar. The BBS conducted a rat-abatement campaign on the islands from 1935 until 1938 and cooperated with territorial agencies working to halt the spread of rat-borne diseases. Field station personnel worked collaboratively with the Hawaiian Sugar Planters' Association (HSPA), the territorial Board of Health, the U.S. Public Health Service, the University of Hawaii’s Agricultural Experiment Station (HAES), the Kauai Planters’ Association, and the Honolulu Chamber of Commerce.

Researchers at the Hawaii field station experimented with chemical agents such as barium carbonate, strychnine, and thallium to control rats in sugarcane fields, and snap traps to control rats in Macadamia nut groves. In addition to the research laboratory where new baits and damage management methods were formulated, the BBS maintained a manufacturing plant to supply premixed rat baits at cost to various territorial agencies. Although the campaign was successful, once it ended in the late 1930s, it wasn’t until the late 1960s that researchers from the Denver lab returned to work on the islands.

By the 1960s, the HSPA and other groups requested the help of the Denver Wildlife Research Center (DWRC) to manage rat damage to Hawaii’s agricultural crops. As a result, a new program to study basic physiological data on rats was established at the DWRC in the mid-1960s. In 1967, Congress appropriated funding for the construction of a new wildlife damage research station in Hilo, Hawaii, as part of the U.S. Dept. of the Interior, Bureau of Sport Fisheries and Wildlife, Animal Damage Control Program. Similar to the previous work done in the 1930s, personnel at the Hawaii field station worked collaboratively with members of the HSPA.

From the late-1960s through the early 1990s, researchers at the Hilo field station studied the effects of various rodent control methods in Hawaii’s sugarcane plantations and macadamia nut orchards. In 1971, zinc phosphide was registered as the first rodenticide in the United States specifically for in-crop use. In 1982, federal funding for the Hawaii field station was cut, leading to its closure in 1983. But by 1989, Congress appropriated the necessary funding to re-open and renovate the Hilo, Hawaii, field station. In 1989, researchers at the station conducted an extensive trapping study to determine the abundance of rat species in Hawaiian sugarcane. In 1991, a telemetry study to determine the movement patterns of rats in macadamia orchards was established.

By the 1990s, many of Hawaii’s sugar plantations were shuttering their operations due to rising land and labor costs. As priorities shifted away from the sugarcane industry, the Hawaii field station, in coordination with other federal and state agencies, conservationists, and private landowners, began developing strategies to reduce rat depredations in native conservation areas. The field station initiated studies to support registration of diphacinone rodenticide baits to protect endanger flora and fauna native to Hawaii. During the mid-1990s, the Hawaii field station began working with the U.S. Department of Defense to research methods of damage management for the invasive brown tree snake on Guam. In the early 2000s, the field station initiated a study to evaluate the use of citric acid to manage invasive coqui frogs at many resorts in Hawaii. Today, the Hawaii field station continues to play a major role in researching and addressing existing and emerging invasive vertebrate problems in the region.