Bamboozled! The demanding diet of a panda bear
The arrival of Zoo Berlin’s panda pair created a whole new task for our staff: providing a continuous supply of bamboo. Every day, each bear eats between ten and 30 kilos of the plant. But few people are aware of just how complex dealing with a bamboo diet can be. Here in Germany, bamboo is most commonly used as an ornamental plant or as material for fancy furniture – and perhaps you’ve eaten the occasional bamboo sprout at a Chinese restaurant. But there is so much more to bamboo than you might imagine. This remarkable plant is extremely strong yet very flexible; durable and fast-growing; sustainable and incredibly versatile. It may not look that special, but bamboo is a real all-rounder.
A fast grower
China alone is home to more than 500 species of bamboo, some of which lignify (become wood) and some of which do not. Many bamboo species grow a few centimetres a week – and some varieties can grow as much as a metre a day if the conditions are just right. These extremely fast-growing species sometimes take just four months to reach their full height.
However, the bamboo culms (hollow stalks) are not harvested until a good three years later, as that is how long it takes for them to fully lignify. Still, compared to oaks, beeches and other European timber sources, three years is not very long at all.
The bamboo used at Zoo Berlin comes from the Netherlands. In response to the fact that seven European zoos – including Madrid and Edinburgh – now keep giant pandas, Dutch company Winkendick decided to start specialising in bamboo as animal feed.
Substance over style
Bamboo’s wide range of uses as a raw material, building material, and fuel has given it the nickname “green gold”. In Asia, the plant has long been valued as an excellent energy source. The stalk is also exceptionally hard and tough, and can only be broken up by pandas thanks to their strong molars and well-developed jaw muscles, set in their large, solid skull.
The main part of a panda’s diet, however, is bamboo leaves. Although the leaves are poisonous to humans in their raw state, the bears are immune to this poison: they have a bacteria called Clostridium in their gut that breaks down the hydrocyanic acid found in bamboo. But in comparison to other herbivores, pandas have relatively low levels of the enzyme. That probably explains why the bears are not particularly efficient when it comes to converting food into energy: only around 17 percent of the bamboo they consume is actually digested.
But not all bamboo is the same. Zoo Berlin’s fussy female panda Meng Meng currently has a fondness for the species Pseudosasa japonica – better known as Japanese arrow bamboo. This robust and low-maintenance variety, which grows up to five metres in height, has been used to make arrows in Japan and China for more than 1,200 years. In those countries, the species is therefore found in abundance close to castles, fortresses and ruins.
But as fate would have it, Pseudosasa japonica is the most difficult species of bamboo to get hold of in the Netherlands. And yet miraculously it is the very species of bamboo that grows right next to the Predator House at Zoo Berlin. This means that, for the time being, Meng Meng’s needs are easily met. What’s more, Jiao Qing’s favourite variety – bisset’s bamboo (Phyllostachys bisseti) – just happens to grow by the Hippo House. It’s almost as if these two pandas were destined to live at Zoo Berlin!
Naturally, there are a number of bamboo species growing in the pandas’ outdoor habitats, too. These grasses not only look attractive, they also helped ease the bears’ initial anxiety about exploring their new surroundings –they simply couldn’t resist the lure of a small snack.
Luck of the draw
Once a week, a refrigerated vehicle turns up at Zoo Berlin containing four or five different types of bamboo. There is always an element of surprise to these deliveries, as only three varieties can be specified in the order. The rest is a bamboo “lucky dip” that serves to give our bears a varied diet and helps us better understand their preferences. Deliveries were originally scheduled for every two weeks – but our cute black-and-white bears are just too gluttonous.
Meng Meng and Jiao Qing also have quite sensitive taste buds, which means the delivery needs to be tweaked every time. Keeper Christian Toll explains that this is partly due to the fact that the flavour of bamboo changes according to the time of year. In addition, the natural movements of pandas in the wild gives the bears tastes and preferences that change with the seasons.
This presents quite a challenge for our keepers, as both bears need to consume some 30 kilos of bamboo a day – a tall order when there is a chance they will turn their noses up at whatever is placed before them. But as complex as this bamboo diet may seem, we are optimistic that we will soon fully solve the secret of our pandas’ demanding diet.