The hippopotamus, nicknamed Owen and weighing about 300 kilograms (650 lbs), was swept down Sabaki River into the Indian Ocean, then forced back to shore when tsunami waves struck the Kenyan coast on December 26, before  wildlife rangers rescued him.

"It is incredible. A-less-than-a-year-old hippo has adopted a male tortoise, about a century old, and the tortoise seems to be very happy with being a 'mother'," ecologist Paula Kahumbu, who is in charge of Lafarge Park, told AFP. "After it was swept and lost its mother, the hippo was traumatized.

It had to look for something to be a surrogate mother. Fortunately, it landed  on the tortoise and established a strong bond. They swim, eat and sleep  together," the ecologist added. "The hippo follows the tortoise exactly the  way it follows its mother. If somebody approaches the tortoise, the  hippo  becomes aggressive, as if protecting its biological mother," Kahumbu  added.  "The hippo is a young baby, he was left at a very tender age and by  nature,  hippos are social animals that like to stay with their mothers for four  years," he explained.

Hippo and Tortoise Pals May Find Three's a Crowd
John Roach for National Geographic News

January 5, 2006

The strength of a unique male bond between a young hippopotamus and a 130-year-old tortoise will be tested later this spring when conservation workers introduce a female hippo to the mix. 

The pending introduction serves as an intriguing plot twist to the unlikely story of a hippo and tortoise brought together at Haller Park wildlife sanctuary in Mombasa, Kenya, in the wake of the December 26, 2004, Indian Ocean tsunami. 

The conservationists hope the two hippos will bond with no objection from the tortoise, named Mzee. Such an outcome will allow Mzee's return to the safety of his original enclosure. 

While other tortoises, monkeys, and antelope roam in that enclosure, Mzee has shown no affection toward any of them. But he has surprisingly become attached to the young hippo, Owen. 

Owen, who weighed an estimated 660 pounds (300 kilograms) when he arrived at the park, was two-thirds the size of Mzee. He is now twice Mzee's size and still growing. 

"He will grow to anywhere between three and four tons—he's gonna be a big male hippopotamus," said Paula Kahumbu, the general manager of Lafarge Ecosystems, the Kenyan environmental restoration firm that manages the wildlife sanctuary. 

"He's already quite playful, already quite strong," she said. "He could injure Mzee at any moment. He's very childlike in his behavior. As he gets older he will get rougher. Mzee is not a flexible animal—he could be injured." 

But how Mzee and Owen will react to the presence of Cleo, the female hippo, and a subsequent separation is unknown, Kahumbu said. If one cannot live without the other, some sort of accommodations will be made. 

For now, the hippo and tortoise are best buddies. The story of their friendship, formed in the wake of the tsunami, has been helping people in the region cope with their own losses, Kahumbu said. 

When the giant waves struck the coast of Kenya, Owen was wallowing with his herd in the ocean near the mouth of the Sabaki River. Too small to escape the waves with his family, he was stranded on a coral reef. 

The next day residents of the village of Malindi rescued Owen with fishing nets. 

But his rescuers were unable to simply reintroduce Owen to another pod of hippopotamuses, because the oldest male would see him as a threat and kill him. 

Conservationists therefore decided to transport Owen to Haller Park, about 50 miles (80 kilometers) away. 

There the hippo immediately ran to Mzee, a 130-year-old Aldabran tortoise who resides at the Haller Park sanctuary. The park is a restored ecosystem that also serves as an orphanage for abandoned wildlife. 

At first the tortoise wanted nothing to do with the hippo, but Owen persisted. Some conservationists suggest that Owen, in search of a mother figure, may have been attracted to Mzee's round shape and gray color, which resemble an adult hippo. 

The first night at the sanctuary, Owen fell asleep next to Mzee. The following morning photographer Peter Greste took a picture of the pair, which was subsequently published in newspapers around the world. 

Hans Klingel is a zoology professor at the University of Braunschweig in Germany and an authority on hippopotamus behavior. He said given hippos' social nature, Owen's attraction to Mzee makes sense. 

"They are social animals," he said in an email. "In that sense, they join whoever is available." 

In the year since the tsunami struck, the bond between hippo and tortoise has strengthened, and now the two are inseparable. They rouse each other for meals, spend hours wallowing in the pond together, and snuggle up side by side each night. 

According to Haller Park staff, Owen behaves more like a tortoise than a hippo. He eats tortoise food, such as leaves and carrots, and ignores the grasses that hippos normally consume. He sleeps at night, not during the day as wild hippos do. And he doesn't respond to hippo calls. 

While Owen's attraction to Mzee may be explained by a baby's need for a mother figure, tortoises are not known for affectionate or social behavior, Kahumbu said. 

Nevertheless, Mzee follows Owen around, nudges him to go for walks, initiates play in the water, and even stretches his neck out so Owen can give him a lick. 

There has been growing evidence of physical communication between the pair, with Owen nibbling Mzee's back feet to get him to walk in a desired direction. The two have even developed a sort of vocal communication of their own, Kahumbu said. 

The vocalizations are not the honking of hippos or the grunts and hisses of tortoises, but rather a soft whimpering that emanates from one and is mimicked by the other. 

"It's very high pitched; definitely not a stomach sound, as some had suggested," Kahumbu said. "They're vocalizing towards each other." 

What the animals are trying to communicate is not yet understood, but researchers think it is a contact call made to get the other's attention. 

Introducing Cleo 

Concerned that Owen's affection for Mzee may lead to an unintended injury, Kahumbu and colleagues are constructing a new enclosure at the sanctuary for Owen and the female hippo, Cleo. 

The researchers hope Owen and Cleo will bond and take to their new grounds, which will be in the public view. They are also trying to accustom Owen to the presence of humans. 

The move is expected to take place this April or May. At that time Mzee will be moved with Owen to the new enclosure to help keep the young hippo calm. 

Once the two hippos are comfortable with each other, Mzee will be returned to his original grounds with other tortoises. 

"We hope Mzee will not be too traumatized by being separated from Owen," Kahumbu said.