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Non-Native Chicago Wildlife

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Mid-February, I took a science-themed trip to Chicago. I absolutely had to visit the new orphaned baby otter adopted by the Shedd Aquarium. I also could not turn down a chance to offer a one year happy birthday greeting to the two toed sloth born at Lincoln Park Zoo last year around Valentine's Day.

First, we will meet Cayucos, John G. Shedd Aquarium's new arrival. A behind-the-scenes visit included dipping the bottom of my shoes in a pan of disinfectant followed by a brief rinse in water to prevent tracking in diseases that could be harmful to the sea otter pup. I was able to view her through a window looking into her pool built specifically for the purpose of nurturing otter pups, full of artificial "kelp", which you will see in the brief video just below. Cayucos decided to nap while I visited, so the cute frolicking we are used to seeing of otters is just not there, but take a look anyway! You will hear my voice and that of Executive Vice President of animal programs and training, Ken Ramirez, explaining how long sea otter pups usually rely on their mothers.


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Before Christmas 2011, three southern sea otters, a species hunted to the brink of extinction for their fur, subsequently added to the endangered species list and making a comeback, were separately found stranded on beaches in southern California by wildlife rescuers. Cayucos was found (and named) in Cayucos, California. After a short stay at Monterey Bay Aquarium, where trainers assisted with her intensive care, she was released to Shedd by the U.S. Fish and Wildlife Service. Read more.

The US Fish and Wildlife Service determined the three otters should be raised in differing locales. The two who were not in good health would be raised by humans for eventual display for the public (Cayucos at Shedd and the other at Sea World (see her video here)) and one would be raised by a surrogate mother, like Toola, the world's first surrogate otter mom, who passed away this month.

When an otter is raised by humans, there are many skills they need to learn, including how to feed themselves, groom themselves, and to sleep in the water. Unfortunately, once they are habituated to humans, they will not gain the skills needed to hunt, so cannot be released into the wild. On the other hand, the otter raised by the surrogate will gain all necessary skills and may be released to the wild in the future.

Here is a video of Cayucos being groomed at the Shedd, courtesy of Shedd Aquarium (no audio):

From Shedd's website: "Keeping the pup’s thick fur clean, dry and fluffed is essential to her survival. Sea otters are the only marine mammals that aren’t wrapped in an insulating blanket of blubber. Instead, they have about 1 million hairs per square inch of skin, divided into an outer layer of thick guard hairs and an inner layer of dense, wooly underfur honeycombed with millions of tiny air pockets. The layers work together to keep water out and body heat in. If the fur becomes matted or fouled with pollutants such as oil, cold sea water penetrates to the otter’s skin and the animal can quickly succumb to hypothermia. Otters shed their fur gradually and throughout the year so that they are never without this vital protection."

I was curious how experts like Ken learned to care for otters, and how to help hand raise them. He shared that most of his experience came when he and others from Shedd Aquarium were called on to help over 2,000 otters who were affected by the Exxon Valdez oil spill in 1989 to help clean them for the reasons stated already. It should be noted that Shedd sends out teams of animal specialists to assist with other oil spills including the recent Gulf Oil spill.

Cayucos is a permanent addition to the Shedd Aquarium and will probably be ready to be introduced to some of the more docile otters already there as summer approaches. If you visit the Shedd Aquarium this summer, you might just get to see Cayucos playfully showing off for visitors. In fact, I will most certainly return so I can see her do more than tumble into the water for a nap!

Out of the water and into the trees

Last February, a new baby sloth, Siesta, was born to parents Chewbacca and Carlos. In fact, I was visiting Lincoln Park Zoo, Chicago's free zoo, last year and was unaware that Siesta had been born as she was hiding with her mother after her long first day! The mother was hiding tucked up under the roof of the thatched hut of their display. It wasn't until I was looking at their website a few days later that I realized a new baby sloth had been born!

This time around, I wanted to be sure to see the new arrival, even though a year had elapsed. With all of the excitement around sloths lately (much in part due to Lucy Cooke's show "Too Cute, Baby Sloths" which I covered here on PsiVid in November), I was even more enthusiastic to meet Siesta.

I spent some time with Small Mammal and Reptile Curator Diane Mulkerin who spoke with me about their Hoffman’s two-toed sloths. I was told that Siesta had begun to wander around without mom in the last few months. Just my luck, the day before I visited, apparently Siesta was moving all around her enclosure and the zoo photographer, John Kortas, was able to get some great shots, but I wasn't able to see her be anything but a curled up ball of fur! Luckily, returning the next day, I was met with the treat of Siesta's dad, Carlos, moving around. Here he is in my video!

Carlos was born at Lincoln Park zoo, living there for many years, and sent away to Chicago's other zoo, Brookfield, for ten years and later returning to LPZ. He has sired seven babies in his life and is 29 years old now (LPZ prides itself on their fairly geriatric population of animals across the zoo who live beyond their life expectancies in captivity). In 2009, Chewbacca, who also goes by Chewy, (currently 21 years old) was brought in to LPZ and introduced to Carlos. It took a while before she was finally pregnant. After a 6-9 month gestation, Siesta was born February 15, 2011, right in the middle of the day! Diane informed me that Chewy gave birth while hanging on the mesh of their enclosure and they found Siesta's umbilical cord wrapped around a branch and mom's legs, yet some how mom and baby extricated themselves and were found obviously just fine!

My visits to Shedd and LPZ taught me quite a bit about population management in zoos and aquariums. Siesta will mating age in about a year, and at that time a zoo population manager will begin to discuss with other zoos about moving her around for mating possibilities.

I had other great discussions about science outreach and activities both at Shedd Aquarium and Lincoln Park Zoo. Informal science activities are very important for children and adults. I'll be sharing more about these opportunities for engaging in science in Chicago soon in a guest post!

Cayucos' images courtesy of Shedd Aquarium

Siesta's images courtesy of Lincoln Park Zoo, John Kortas

Joanne Manaster is a university level cell and molecular biology lecturer with an insatiable passion for science outreach to all ages. Enjoy her quirky videos at www.joannelovesscience.com, on twitter @sciencegoddess and on her Facebook page at JoanneLovesScience

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