Orangutan mums win breastfeeding by hanging in there for over eight years

And the most dedicated award goes to... Orangutang mamas.

Researchers have found that orangutans breastfeed their young for even longer than was previously believed. It turns out that these supermums use their milk cyclically to keep breastfeeding for eight years, or even longer in some instances. These animals are naturally reclusive in the wild and their privacy-seeking behaviour has made it difficult for observers to say how long orangutan mums nursed for. But brand new findings have found more clues, by examining their teeth. Lead author Tanya Smith, of the Australian Research Centre for Human Evolution, explains:

"We've found the first evidence for a seasonal pattern of increasing and decreasing milk consumption over several years, which is unexpected as primates are conventionally believed to simply increase milk consumption after birth, reach a plateau, and then decrease consumption as they transition onto solid foods and then stop suckling. This kind of behavioral flexibility in orangutans may be unique, but we'll need to investigate other wild primates' nursing histories to know."

Smith and her team examined orangutan teeth (obtained from museums) for chemical signs of breastfeeding. Human and primate teeth are similar in that they build up gradually as we mature, forming layers that are similar to the rings inside trees. These layers can then be used to build a picture of diet and environment. The study found that orangutans primarily relied on their mother’s milk when they were very young. As they grew, they went through stages where they would breastfeed more, but sometimes less. The researchers think this variability is linked to the availability of other food. The teeth demonstrated that some mamas had breastfed for over eight years and the team say that the study opens up other dental research avenues into breastfeeding in humans and even our ancient ancestors. Orangutan mamas, we salute you!