Toxin Tolerance

Natural resource scientists Rod Sayler and Lisa Shipley holding pygmy rabbits.

For more information about pygmy rabbit research, watch this short video:

The endangered pygmy rabbit subsists almost entirely on sagebrush, which is avoided by most herbivores because it contains toxic levels of terpenes. Terpenes, compounds produced by plants, are believed to be a defense mechanism against munching herbivores. Understanding such adaptations for tolerance to toxic plants is central to understanding plant-animal interaction - that’s why associate professor of natural resource sciences Lisa A. Shipley focused on conducting experiments, learning field techniques, and sharing insights and information with other researchers interested in the same topic during her sabbatical.

Shipley spent the first six months of her leave in Australia, where ancient, infertile soils give rise to communities of plants with particularly high levels of diverse toxins. As a result, most arboreal herbivores there have adapted to eating toxic plants such as eucalyptus. Working primarily in Bill Foley’s lab at Australian National University, Canberra, Shipley learned that specialist animals do indeed have a better ability to process and detoxify terpenes.

Once she returned to WSU, Shipley applied what she learned in Australia to her pygmy rabbit research. Drawing on her field experience, she collected pygmy and cottontail rabbits for captive work. Feeding trials conducted on the animals revealed that the pygmy rabbit can subsist exclusively on sagebrush, even if only for a short time.

“The pygmy rabbit is a bit of an enigma,” she said, “because it’s the only known mammal that can survive on this diet. We want to find out how.” Although the biological reason remains unknown, Shipley’s research is zeroing in on the answer.

--Phil Cable, Marketing and News Services