Happy feat: penguin forensics prove less burdensome
Feather analysis could revolutionise the size and scope of animal tracking studies.
How do you track a penguin? This is a question of critical importance to a wide range of researchers – including ornithologists, ecologists, climate scientists and fisheries boffins – but one that, until now, has been challenging to answer.
The standard way of monitoring penguins as they migrate to and from breeding grounds has been to attach electronic devices to them. These, however, have a number of drawbacks: not only are they expensive to make and tricky to secure and retrieve, they can also hamper movement – thus affecting the birds’ behaviour and potentially invalidating whatever data they collect.
Now, however, US scientists have come up with a new way of uncovering the secrets of penguin migration – and all it requires is a tail feather.
In a paper published in the journal Biology Letters, a team led by Michael Polito of Louisiana State University report geochemical data extracted from the tail feathers of Adelie and Chinstrap penguins (Pygoscelis adeliae and antarcticus) can yield the unique chemical signatures of the birds’ over-wintering areas.
Polito and his colleagues uncovered the information in the feathers by extracting amino acids and subjecting them to a technique called compound-specific stable isotope analysis.
The use of tail feathers as geo-markers came about as the result of an extension of a mission to retrieve tracking devicesn. Attending a penguin breeding zone to collect monitors they had secured to 52 birds the previous year, the scientists also took a single feather from each bird, then collected feathers from another 60 birds not tagged.
Back at the lab, the data collected by the tracking devices was correlated against the results of the isotope analysis of the feathers. Using this as a foundation dataset, the scientists were then able to identify the wintering locations of the untagged birds from feather forensics alone.
"This novel approach could be applied to different tissues from a wide variety of marine animals that migrate over long distances including seabirds, sea turtles, seals and whales," Polito says. "Using stable isotope forensics to increase the size and scope of animal tracking studies will help us to better understand these charismatic species and ultimately aid in their conservation."