A federally funded analysis led by Brown University biologists found that different species of large herbivores have diets that are more diverse and complex than previously known.
PROVIDENCE, R.I. [Brown University] - Scholars and schoolchildren alike have generally classified animals by the foods they eat: carnivores eat meat; browsers consume flowering plants, conifers and shrubs; and grazers focus on grasses.
But a new federally funded study led by Brown University biologists and scientists at Yellowstone National Park revealed that different circumstances lead herbivores to eat a much wider variety of plants than previously believed.
Published in the Proceedings of the National Academy of Sciences, the new research suggests that the traditional classification schemes that distinguish herbivores by their percent of grass consumption are oversimplifications that can fail to reflect dietary variation within and across species, said study co-author Tyler Kartzinel, an associate professor of ecology, evolution and organismal biology at Brown.
"This challenges biologists to consider whether we're finding patterns in nature that reinforce our perceptions of what animals should be doing rather than what they are actually doing," Kartzinel said. "It makes a very compelling case that in Yellowstone, we're putting animals into boxes that include all members of a species but not considering the differences in eating behaviors within species or - perhaps more importantly - some of the similarities that unite different species."
According to Kartzinel, this type of research can help scientists better anticipate the resources that wildlife use in changing landscapes where there are diverging opinions on conservation strategies.
"These findings are a big step toward understanding how so many species of large mammals can survive together in Yellowstone," Kartzinel said. "Our findings suggest that maintaining plant diversity is a critical requirement for maintaining the diversity of migratory wildlife."
When grazers become browsers
The research team has been studying animal foraging behaviors in Yellowstone for seven years. In a study published last year in Royal Society Open Science, the researchers focused on what the average member of herbivore species was doing to find food in Yellowstone.
