Scientists Discover How Sloths Can Breathe Easily Upside Down
Posted on April 28, 2014
Sloths inhabit rainforests in South and Central America. They spend a lot of time hanging from their hind legs to reach leaves growing on the tips of trees. Scientists have determined how sloths manage to breathe easily while hanging upside down. The discovered that sloths have fibrinous adhesions that prevent their internal organs from weighing down on their lungs. The research was carried out by the Swansea College of Science, with colleagues from the Sloth Sanctuary in Costa Rica. Swansea University researcher Rebecca Cliffe is pictured above fitting a backpack to a sloth. The backpacks enables researchers to monitor the sloths.
The researchers found numerous unique adhesions in the abdomen anchor organs such as the liver, stomach and kidneys. These adhesions prevent the organs from pressing on the diaphragm while sloths are hanging upside down and inhibiting breathing.
Even digestion is slow for sloths. They can take a month to digest one leaf. They only deposit urine and feces about once a week, which means the contents of their stomach and bowels can grow heavy. This means every bit of energy they can save - thanks to the special adhesions - is crucial. The scientists estimate the adhesions can save sloths up to 13% in energy expenditure when they are hanging upside down.
Cliffe says in a statement, "Sloths have multiple internal adhesions that bear the weight of the stomach and bowels when the sloth hangs inverted. We estimate that these adhesions could reduce a sloth's energy expenditure by 7 - 13% when hanging upside down. To a sloth, an energy saving of 7 to 13 percent is a big deal. They generate just about enough energy from their diet to move when and where required, but there is not much left in the tank afterwards. t would be energetically very expensive, if not completely impossible, for a sloth to lift this extra weight with each breath were it not for the adhesions. The presence of these simple adhesions therefore really is vital."
A research paper about the findings was published here in the journal, Biology Letters. The finding was made on three-fingered sloths, Bradypus variegatus.