Muskoxen hair analysis shows diet suffers during snow-heavy Arctic winters

Hair records reveal dietary chronology in high resolution, enable new way of monitoring for remote tundra animals

Date:April 20, 2016

Source:PLOS

Analysis of hairs from muskoxen in the Arctic tundra indicates they had limited amounts of forage available and relied heavily on body stores during snow-heavy winters, according to a study published April 20, 2016 in the open-access journal PLOS ONE by Jesper Bruun Mosbacher from the Arctic Research Centre at Aarhus University, Denmark, and colleagues.

Like other northern hooved animals, female muskoxen are more likely to bear calves when they have ample fat and protein stored for the winter, a state that strongly influences population demographics. Continuously growing tissues, like hair, provide a fairly long-term record of animal diets in the form of δ15N, a nitrogen isotope that varies seasonally in many grass-fed animals, and muskoxen guard hairs grow continuously for several years. The authors of this study clipped guard hair samples from the rumps of 10 muskoxen and used isotope analysis to reconstruct their diets in Northeast Greenland over the previous two and a half years, achieving a resolution of about nine days.

The researchers found that the diets of muskoxen were closely linked to changes in the temperature and snow depth. While summer diets were similar from year to year, winter diets varied widely, likely caused by large variations in the snow depth between winters. In particular, increased δ15N values were seen in muskoxen guard hair in winters with heavy snowfall. This indicated that the muskoxen had very limited access to forage and relied more heavily on their body stores to get through these extreme winters.

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Adorable sea turtles don poop-catching swimsuits for science

OCTOBER 5, 2015

by Eric Hopton

Meet the half-shell heroes who have donated their excrement to science. It’s loggerhead haute-couture with a poop capture mode, and these Aussie turtles are doing their bit for conservation.

It all started when researchers at the University of Queensland wanted to collect loggerhead feces. (No, it’s not some weird hobby.) These guys were studying the diet of endangered sea turtles to help find their feeding areas, and they hoped this would lead to better ways to protect the species.

But the scientists ran into a problem. The turtles can weigh up to 260 pounds, and catching their poop as they swam in the ocean was no easy job.

So Owen Coffee, a PhD student at UQ’s School of Biological Sciences, with fellow UQ researcher Carmen da Silva, began to explore possible solutions. They captured six loggerhead sea turtles and kept them in seawater tanks at UQ’s Moreton Bay Research Station until they pooped.

“However, it was challenging to collect the entire faecal sample once it dispersed into the water. So we developed a flexible funnel anchored to the shell, to fit over the turtle’s tail. But this was not a good answer either. Because the animals are so large, it was difficult to keep the devices in place,” said Coffee.

A brilliant idea

Then Doctor Kathy Townsend, Moreton Bay’s education coordinator, remembered that researchers had previously developed soft, flexible harnesses when studying the vision of sea turtle hatchlings. The harnesses were made out of swimsuit material and were a snug fit on the turtle’s shell.

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