Orangutans are the most \"economical\" primates

The rate of metabolism in orangutans was the lowest among the primates and one of the lowest among mammals in general. The number of calories, which consumes active orangutan, is comparable with the amount spent by sloth, most of the time conducting in the stillness. Article describing the unusual metabolism orangutans published in the journal Proceedings of the National Academy of Sciences.

The researchers examined four orangutans living in the reserve in Iowa, where animals live in conditions close to the wild. To determine how much energy spent monkeys, the researchers gave them the so-called heavy water - water in which instead of "ordinary" hydrogen isotope protium used heavier deuterium. Scientists trained orangutans to urinate in individual containers and evaluated in urine of deuterium. The difference in the amount of its drinking water and urine due to the fact that some of the deuterium evaporates in the form of carbon dioxide, which is produced from the burning of fats, proteins and carbohydrates. That is, estimating the number of deuterium "gone", the researchers can calculate how much energy was spent animals. In addition, the researchers kept tabs on the orangutans of food eaten.

It was found that the monkeys spend very little energy, despite the fact that most of the time they spend in traffic. Scientists have found that the rate of metabolism orangutans are second only to sloth and oviparous mammals, which in principle are different strange metabolism.

The authors suggest that the low level of metabolism developed at orangutans because of their lifestyle - these monkeys feed mainly on fruit, and occasionally they have many days do without food.

Orangutan - are apes that are among the closest relatives of Homo sapiens. Last year, the team of scientists, focusing on a large number of morphological characters, concluded that orangutans are the closest neighbors to be on the evolutionary tree. In this genetic study indicate that this place should have a chimpanzee.