Johannesburg - A South African bird famous for its ability to carry water in its feathers could soon be the inspiration for super absorbent materials, including water bottles that don’t slosh.
The male Namaqua sandgrouse ferries water back to his thirsty chicks by holding it in its feathers. He does this by dunking his belly in water and then typically flies 35 kilometres back to the nest.
What makes the journey even more remarkable is that the sandgrouse will get to speeds of up to 66 kilometres an hour carrying cargo that is 15% his body weight. The bird’s speed allows it to get back to the nest before the water evaporates.
The male sandgrouse is the only bird known to do this.
The super absorbent qualities of the male sandgrouse belly feathers have been long known about, but only now are researchers taking a close up look to see what is going on at a microscopic level.
To do this, researchers at Johns Hopkins University and Massachusetts Institute of Technology turned to high resolution microscopes and 3D technology.
It revealed for the first time how the male sandgrouse’s feathers are able to hold water so efficiently.
“It’s super fascinating to see how nature managed to create structures so perfectly efficient to take in and hold water,” said Jochen Mueller, an assistant professor in Johns Hopkins’ Department of Civil and Systems Engineering, in a statement. “From an engineering perspective, we think the findings could lead to new bio-inspired creations.”
First the team examined both dry and wet feathers under magnification.
Each of the feather shafts are a fraction the size of a human hair.
By dunking the dry feathers in water, very much like what a male sandgrouse would do when at a watering hole, the researchers were able to see how the structure is optimised to hold water.
They were able to describe how the barbules on each of the feathers formed protective tent-like structures. Tiny tubular structures in each of the barbules capture water. Individual feathers also held water through what the researchers described as a forest of barbules near the shaft.
“That’s what excited us, to see that level of detail,” Mueller said. “This is what we need to understand in order to use those principles to create new materials.”
The feathers used in the experiments were taken from a specimen of Namaqua sandgrouse housed in the Harvard Museum.
This pigeon-sized bird is usually found in the Kalahari Desert, the Karoo and in parts of the Western Cape, where every morning flocks of them are seen heading to watering holes.
In the future, applications inspired by the belly feathers of the sandgrouse could include netting that collects and retains water harvested from dew or fog in desert regions.
Also a future water bottle that could hold a lot of liquid, but with an inner similar feather-like structure that could keep water from sloshing around.
An application that the researchers believe runners might be keen on.
The team now plans to see if they can adapt the sandgrouse feathers to commercial applications.