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Invasive Parakeets’ Role in Spreading Invasive Weeds

Rose-ringed parakeets are an invasive species in Hawaii with more than six thousand individuals residing on Kauai. These birds destroy crops, but impacts to other native and non-native species are largely unknown. NWRC researchers teamed up with WS Operations field specialists to analyze the diets of 64 rose-ringed parakeets from five sites on Kauai. All parakeets harvested had vegetation in their crops and gizzards, and 80 percent of the contents (by mass) was seed. The most frequently occurring food items were corn, which occurred in 67 percent of all birds and averaged 31 percent of their diet, and yellow guava, which occurred in 97 percent of all birds and averaged 30 percent of their diet. Parakeets are potentially dispersing invasive yellow guava seeds, as 66 percent of the birds sampled had an average of three intact guava seeds in their crops and gizzards. These findings of a diverse plant diet, frequent seed predation, and potential to disperse invasive plant seeds implies that land managers in agricultural, urban, and natural areas should be concerned with the current expansion of these invasive birds on Kauai and elsewhere. For more information, please contact

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