Picky koalas
Koalas are known to be fussy eaters. They will only eat the leaves of certain specific eucalyptus species. However, the habitat of koalas is shrinking due to climate change, deforestation and drought. Even when these marsupials are shifted to another location with sufficient food, some of them still tend to die. According to Western Sydney University scientists, two factors are responsible: the available eucalyptus varieties and the koala's intestinal flora.
Diet preferences
When analysing the poo of 200 koalas living in 20 different locations in Australia, scientists found two species of eucalyptus. Some of the koalas consumed the nutritious manna gum (Eucalyptus viminalis), while others ate the less nutritious messmate (E. obliqua). However, a small minority ate both. Even koalas living just 10 metres from one another can have different preferences. Analysis showed that the intestinal bacteria of koalas that consumed manna gum were different than those of the messmate eaters.
Poo transplant
In order to discover whether the eucalyptus preference was due to a difference in gut microbiota, the scientists conducted a poo transplant . Six wild koalas that ate the nutritious manna gum received donor poo from messmate-eating koalas. After 18 days, the gut microbiota of the koalas that received the transplant was practically the same as that of their donors, with the result that the manna gum-eating koalas now preferred messmate. This discovery showed that intestinal flora have a huge impact on an animal's food preference. Changing the bacteria means that another, more widely available diet becomes possible, which could help prevent animals from becoming extinct.
More fertile
In another study, the same principle was applied with regard to the endangered white rhinoceros (Ceratotherium simum) and the Indian rhinoceros (Rhinoceros unicornis) at San Diego Zoo in the United States. A poo transplant made the white rhino, which has difficulty reproducing in captivity, more fertile.
Source: Nature