Density estimation for marine mammal species is performed primarily using visual distance
sampling or capture‐recapture. Minke whales in Hawaiian waters are very difficult to sight;
however, they produce a distinctive “boing” call, making them ideal candidates for passive
acoustic density estimation. We used an array of 14 bottom‐mounted hydrophones,
distributed over a 60× 30 km area off Kauai, Hawaii, to estimate density during 12 d of
recordings in early 2006. We converted the number of acoustic cues (ie, boings) detected …

Reliable estimation of the size or density of wild animal populations is very important for
effective wildlife management, conservation and ecology. Currently, the most widely used
methods for obtaining such estimates involve either sighting animals from transect lines or
some form of capture‐recapture on marked or uniquely identifiable individuals. However,
many species are difficult to sight, and cannot be easily marked or recaptured. Some of
these species produce readily identifiable sounds, providing an opportunity to use passive …