Dr. Chris Farmer measures the tarsus of a palila

Palila, a critically endangered Hawaiian bird found only the slopes of Mauna Kea volcano, Hawai‘i Island, Hawai‘i, have faced several threats including invasive cats, rats, and mongoose, and loss of habitat. Dr. Paul Banko has spent decades of his career studying palila populations and threats. In this photo, Dr. Chris Farmer measures the tarsus (lower leg bone) of an adult palila.