Updated at 8:59 am on 18 November 2015
A team from American Samoa's Department of Marine and Wildlife resources is heading to the Manu'a islands to conduct a survey of the native bird population.
Ornithologist Kim Kayano, who is leading the six-person team, says studying the bird population will also give researchers an idea of the health of other organisms.
She says there is evidence that invasive bird species have forced a decline in the native population on the main island, Tutuila.
"We found that birds in Tutuila are much less abundant than the ones on Manu'a and so we're still trying to find out why that is, but human population size, urban development, as well as the presence of invasive species, we think, are factors in the less birds that are found on Tutuila."