The Guam kingfisher is extinct in the wild. For now. Scientists have been caring for a small flock of these rare birds at the Smithsonian Conservation Biology Institute. To get one step closer to rewilding the species, they need to launch a study gathering key information about how they can successfully breed them. Kingfishers can be difficult to match with a mate, so by learning more about the species’ hormones, they will be better able to encourage successful pairings. That way, they can bolster the population with a new generation of chicks, reintroducing a flock to the wild within the next few years.