This Rodent Eats With Needles

This rodent is one tough customer, and a cactus's nightmare. Recent research has found that the very spines and needles that normally act like a deterrent for potential predators actually draws one species of woodrat in, as if the needles point their way to the best meals.

The white-throated woodrat (Neotoma albigua) is a relatively small and unassuming rodent commonly found in the deserts of the south-western US. In harsh regions like that, hardy grasses and cactus are one of the few means of survival for tiny mammals. However, while most rodents will avoid cactus with long spines and needles for fear of harm, the white-throated woodrat seem to almost enjoy the danger, carefully sliding between needles in order to get at soft cactus flesh.

In order to prove that these little daredevils actually prefer eating needled cactus over smooth ones, researchers simply offered a spiny cactus alongside one of the same species whose spines has been removed to a host of the rats.

The results were recently published in the journal Oikos.

"The results were extremely clear," researcher Kevin Kohl of the University of Utah told New Scientist. "Every animal preferred the spiny cacti over the ones without spines."

So why is this? Kohl and his colleagues believe that the rodent is choosing spines over an easier meal because the flesh of spiny cacti generally has a higher protein content and less fiber compared with naturally non-spiny cacti. In that sense, the woodrats are using the spines almost as a simple nutrition label.

Even more interesting, after the brave rodents are done with their meal, they gather the leftover spines and use them to line their nests, so intruders unfamiliar with the structure will be in for a painful surprise

"It's the ultimate workaround," added the study's senior author, Denise Dearing. "This research demonstrates the unpredictable twists and turns that evolution can yield in the arms race between plants and herbivores."

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