Spring cleaning

Source: news.bbc.co.uk, photo Jill Sonsteby
It seemed as if the zebra's final hour had struck. At least, that is what the visitors in Zurich Zoo thought when they saw a zebra put her head in the mouth of a hippopotamus. But the enormous jaws were not jammed shut however. On the contrary, the hippo was grateful for the cleaning session.
The hippopotamus is regarded as an aggressive species. Although the animals are plant eaters and do not easily kill each other, humans regularly fall victim to hippos. The animals do not look like fast runners, but on land they can run up to 30 kilometres per hour and can therefore outrun a human. Also boats are regularly turned upside-down and destroyed, and the fate of the passengers usually looks grim. The bite of a hippo is powerful enough to cut a crocodile in half. It is particularly dangerous to come between a hippo and his or her pool.
In Zurich Zoo zebras and hippos share an enclosure. The hippo opened her mouth and let the zebra clean her teeth. This cleaning session lasted 15 minutes and was observed with disbelief by the zoo visitors.