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A Second Litter of North American River Otters Born at the Milwaukee County Zoo

Otter pup
Clover likes to keep her pups near to her in the nest box.

Updated July 2022


Keepers are thrilled to share that both Shamrock and Clover’s litters are flourishing. All seven have been eating solid foods for at least a month, although Clover’s are nearly weaned and only nurse sporadically. Each of the pups weighs between 5-6 kilograms – full-size is considered 8-10 kilograms, so they are almost there! The litters are extremely playful and rambunctious and love to wrestle with their siblings. Keepers report that Clover is a very playful mother, while Shamrock is more of a “business mom.” The pups are already able to do everything that the adults do: hold their breath as long as they need to, eat whole fish, and more. They even weigh themselves (because they’re curious, not because they’re trained). They enjoy investigating any potential enrichment toy, and their favorite leisure activity is sleeping in hammocks.

Dad Larkey continues to be separated, because the mothers are still very protective of the pups – so they continue to rotate outside and overnight.

It’s official, the Milwaukee County Zoo now has a romp (a group of otters is called a “romp”) of North American river otters! The pups now have names: the two males are named Alex and Flannery, and the female is named Mallory.

One of the Zoo’s female otters, 5-year-old Clover, and male otter, Larkey, also 5 years old, are parents to three otter pups, born February 26. Two male and one female pup are the first litter for Clover, and animal care staff report parents and pups are doing well!

Visitors may remember the Zoo’s other adult female otter, Shamrock, gave birth to four pups February 7. Larkey is father to this litter (of four) as well.

Otter pup
Two pups cuddle together in a nest made of wood shavings.

As a first-time mom, Clover is “super protective” of her pups and usually keeps them very near to her, according to her keepers. She doesn’t separate easily from the pups, sometimes even choosing to stay close to them instead of eating! As a result, keepers work with Clover on her time, and if she chooses to separate from the pups, they use the opportunity for brief exams and weights. So far, keepers have been able to record weights twice per week. At about 3 weeks old, each of the pups weighed between 600-700 grams.

By comparison, Shamrock’s pups now weigh over 1,000 grams, and they’re nursing and keeping mom busy (and hungry)!

Animal care staff report Clover’s pups are nursing and right on schedule with weights and development. They gain weight each time they’re weighed.

Clover and her pups are in an indoor holding area, with Larkey in the outdoor habitat. Keepers gave Clover soft, natural bedding material so she can make warm and comfortable nests for herself and the pups. She likes to experiment by moving the nests and the pups to different areas. Right now, she doesn’t seem to have settled on one area for her and the pups to stay for longer periods of time. Keepers think Clover simply chooses the area and nest that are most comfortable for the pups.

Otter pup
One pup sleeps in a nest of woodwool.

The pups should be fully weaned at 3-4 months. In 42-56 days, they’ll begin eating fish that keepers will “mash” for them, or fish that Clover drops from her mouth! North American river otter pups are born with their eyes closed, and they’ll remain closed for about 1 month.

As the pups continue to grow and mature, they’ll begin to “squirm” and “belly crawl” in the holding areas. It’s expected the pups will learn how to swim from mom, at about 1 ½ months old. They will walk first, and then learn how to swim in the indoor pool.

The pups marked their 1-month birthday March 26, and mom and the pups, who have yet to be named, will remain off-exhibit for the next few months. Animal care staff are keeping a watchful eye on them, and the Zoo will regularly update visitors on their progress.

Video: Meet Clover and Larkey’s pups born Feb. 26.