Imaging chemical elements in bird feathers

Researchers led by the Australian Nuclear Science and Technology Organisation (ANSTO) have been using X-ray imaging on the feathers of long-distance migratory seabirds. The results of their study, published in the journal Nature Scientific Reports, could lead to important new insights into the evolution and health of birds.

Using the X-ray fluorescence microprobe at the Australian Synchrotron, the researchers were able to detail previously undocumented patterns and properties of feathers, which act like a barometer that can indicate the health of individual birds and their environments. These feathers came from three species of migratory shearwaters — birds that are known to travel over 60,000 km per year on their migration to breeding areas.

“The highly sensitive instrument allows us to view hard biological structures in their natural state,” said Professor Richard Banati, a lead researcher on the study. “The detector speeds up scanning of the sample and delivers data at unprecedented resolution.”

The technology produced a map which shows a range of chemical elements distributed in the feather (zinc, calcium, bromine, copper and iron) — patterns that are not linked to pigmentation, thickness or other structural characteristics, according to the study authors. The researchers were particularly intrigued to find a regular pattern of bands containing zinc, which may reflect the estimated number of days of active feather growth or the duration of the moult period.

“Our collaboration has produced some remarkable depictions of the feathers that let us see into complex and pattern-forming, biochemical processes in cells,” said Professor Banati.

It is thought that these patterns may one day help scientists assess a bird’s overall health retrospectively, in the same way tree rings indicate environmental past environmental events like droughts or floods. The research also has significant potential for application more broadly in developmental biology.

“Such highly regular, biological patterns hold important information, because, similar to tree rings, they are a natural time stamp that records events during the growth of these patterns,” said Nicholas Howell, also a lead researcher on the study.

Image caption: High-resolution X-ray fluorescence microscopy images of elemental distributions within a breast feather from a flesh-footed shearwater (Ardenna carneipes).