Male sperm whales are under pressure to grow larger in order to increase their mating opportunities, which could lead them to more efficiently forage in high latitude feeding grounds. Movement patterns of male sperm whales in Nemuro Strait, Japan, were investigated horizontally and vertically using land-based observation and bio-logging methods to determine how they facilitate foraging in the narrow submarine canyon. Eleven ta...

The abundances of six delphinids off the Pacific coast of Japan were estimated using line transect survey data collected in 1985, 1992, 2006, 2007, 2014, and 2015. A multiple covariate distance sampling method was used to estimate a detection function. Because of unsurveyed blocks in 2006, 2007, and 2015, total abundance was estimated only in 1985, 1992, and 2014, when the estimated abundances were for the 3 yr respectively 3,...

A depth and temperature data logger was deployed by air gun on an individual Baird’s beaked whale ( Berardius bairdii ) off the Pacific coast of Japan. The retrieved data logger recorded 81 dives over approximately 29 h. The maximum recorded depth and the longest dive duration were 1777 m and 64.4 min, respectively. All dives were classified into three categories by depth: deep dives (>1000 m), intermediate dives (100–1000 m),...