Taste test? Deer preferences seem to be helping non-native invasive plants spread

Date: April 28, 2016

Source: Penn State

Selective browsing by white-tailed deer likely is promoting the spread of some invasive plant species in northeastern U.S. forests, as deer avoid eating vegetation they find unpalatable.

That's the conclusion of researchers who conducted a study of deer dietary choices at the Penn State Deer Research Center, during which captive deer were simultaneously offered a selection of eight nonnative invasive and seven native plants to determine the animals' preferences.

The research is important because it quantifies interactions between deer and invasive plants -- and how, over time, deer might be exacerbating problems with nonnative plant species, according to researcher David Mortensen, professor of weed ecology in Penn State's College of Agricultural Sciences. He expects the findings to contribute to the conservation of forest understories and natural areas.

"This study provides evidence that deer impacts on plant invaders depend on plant species' palatability," he said. "Consequently, deer selectivity likely plays an important role in the invasion process. To the extent that herbivory impacts plant communities, these results suggest that deer promote the spread of some plant invaders by avoiding them."

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