North American River Otter
Origin: North America
Size: Adults can weigh between 11 and 30 lbs.
Males tend to be larger than females
average between 26 to 46in in body length
Lifespan: In captivity average 21 years, and in the wild 8-9 years
Activity: Generally nocturnal
Reproduction: Breeding season is from December to April.
Female estrus lasts about a month per year, and true gestation lasts 61 days. River otters delay implantation up to eight months
Young are born between February and April. Birthing process can take three to eight hours
Litter size can be up to five pups but tends to average three pups
Otter pups are weaned at 12 weeks they are at adult weight at 3-4 years of age
Females raise the young alone.
Mothers intorduce the pups to water at two months of age
Otters often operate as family units with mothers and offspring and sometimes fathers as well
Yearlings will venture out in search of new territories
Many young males will establish male groups
Extra Facts: The river otter is a semi aquatic mammal
It establishes a burro close to the waters edge
The den usually has many tunnel openings, One of which allows the otter to enter and exit the water
their right lung is larger than their left, Having four lobes compared with two for the left. It is believed to be adaptive for underwater swimming.
river otters have 36 teeth
They travel up to 26 miles in one day
Often beavers anfdotters share the same ponds or streams
They can swim at speeds of up to 6 mph