In Chinese coastal waters and the Yangtze River, finless porpoises are generally found in groups of three to six, although aggregations of up to about fifty have been reported.
In Japanese waters, groups appear to be smaller, with pairs being typical, and even rare aggregations being no larger than thirteen individuals.
Recent data suggest the basic unit of a finless porpoise pod is a mother/calf pair or two adults, and schools of three or more individuals are aggregations of these units or of solitary individuals.
Social structure seems to be underdeveloped in the species, and the mother/calf pair is probably the only stable social unit.

Like other porpoises, their behaviour tends to be not as energetic and showy as that of dolphins.
They do not ride bow waves, and in some areas appear to be shy of boats.
In the Yangtze River, finless porpoises are known to leap from the water and perform "tail stands".

Finless porpoises make both high frequency clicking sounds, and longer, low frequency tones, the latter perhaps being for communication, rather than echolocation.
The clicks are narrow-band, with peaks of over 100 kHz.

A new study from Woods Hole Oceanographic Institution (WHOI) study that was published in The Journal of Experimental Biology, "highlights the differences in dolphins' ability to hear across species, reshaping the previous 'one-size-fits-all' approach taken on the hearing ability of the cetaceans".
In Chinese coastal waters and the Yangtze River, finless porpoises are generally found in groups of three to six, although aggregations of up to about fifty have been reported. In Japanese waters, groups appear to be smaller, with pairs being typical, and even rare aggregations being no larger than thirteen individuals. Recent data suggest the basic unit of a finless porpoise pod is a mother/calf pair or two adults, and schools of three or more individuals are aggregations of these units or of solitary individuals. Social structure seems to be underdeveloped in the species, and the mother/calf pair is probably the only stable social unit.
Like other porpoises, their behaviour tends to be not as energetic and showy as that of dolphins. They do not ride bow waves, and in some areas appear to be shy of boats. In the Yangtze River, finless porpoises are known to leap from the water and perform "tail stands".
Finless porpoises make both high frequency clicking sounds, and longer, low frequency tones, the latter perhaps being for communication, rather than echolocation. The clicks are narrow-band, with peaks of over 100 kHz.
A new study from Woods Hole Oceanographic Institution (WHOI) study that was published in The Journal of Experimental Biology, "highlights the differences in dolphins' ability to hear across species, reshaping the previous 'one-size-fits-all' approach taken on the hearing ability of the cetaceans".
Finless porpoise