<P> North American river otters are highly mobile and have the capacity of traveling up to 42 km (26 mi) in one day . Daily movements of yearling males and females in Idaho averaged 4.7 and 2.4 km (2.9 and 1.5 mi) in spring, 5.1 and 4.0 km (3.2 and 2.5 mi) in summer, and 5.0 and 3.3 km (3.1 and 2.1 mi) in autumn, respectively . Daily movements of family groups averaged 4.7, 4.4, and 2.4 km (2.9, 2.7, and 1.5 mi) in spring, summer, and winter, respectively . Both males and family groups travel drastically less during winter . </P> <P> River otters are renowned for their sense of play . Otter play mostly consists of wrestling with conspecifics . Chasing is also a common game . River otters rely upon play to learn survival skills such as fighting and hunting . However, playful behavior was found in only 6% of 294 observations in a study in Idaho, and was limited mostly to immature otters . </P> <P> Prey is captured with a quick lunge from ambush, or more rarely, after a sustained chase . River otters can remain underwater for nearly 4 minutes, swim at speeds approaching 11 km / h (6.8 mph), dive to depths nearing 20 m (22 yd), and travel up to 400 m (440 yd) while underwater . Several river otters may even cooperate while fishing . Small fish are eaten at the surface, but larger ones are taken to the shore to be consumed . Live fish are typically eaten from the head . </P> <P> River otters dry themselves and uphold the insulative quality of their fur by frequent rubbing and rolling on grass, bare ground, and logs . </P>

How long can a river otter stay under water