Aug. 6 (UPI) -- Plant-eaters, not predators, are at a greater risk of extinction, according to a new survey of more than 24,500 species.
For the study, published in the journal Science Advances, researchers organized and analyzed previously collected data on the extinction risk and diets of thousands of birds, mammals and reptiles.
The analysis showed 25 percent of herbivores are at risk of extinction, while only 15 percent of carnivores face the risk of extinction.
Approximately 17 percent of omnivores, species that eat both meat and plants, are at risk, the study said. And among all groups, the data showed larger animals are more at risk than smaller animals.
Scientists say they have often predicted that large predators -- because they eat larger amounts of food and roam across larger swaths of land -- are most at risk of extinction.
"The results were somewhat shocking," lead study author Trisha Atwood said in a news release.
"Our highly publicized and fraught relationship with predatory animals such as lions and wolves has led to the unfounded perception that we are losing predators more than any other trophic group," said Atwood, a researcher at Utah State University.
Overall, researchers found that herbivores were the most threatened, but the data showed a few specific groups of meat-eaters face an especially great risk of extinction. This includes scavengers like vultures, as well as animals that mostly prey on fish, such as seabirds.
"These surprising results don't change the nature of our race to save biodiversity, but they do drive home how quickly we must act," said co-author Will Pearce, life scientist at Imperial College London. "Preserving and restoring the entire of ecosystems, not just charismatic carnivores, is vital if we are to maintain a healthy and productive planet."
Among herbivores, the analysis showed plant-eating reptiles were particularly vulnerable, researchers said. Tortoises, for example, are especially sensitive to the threats of invasive species.
The new research also revealed connections between groups at the highest risk of extinction and the specific threats posed by human activities.
"Documenting a pattern in extinctions is only the first step towards curbing the loss of species," said Atwood. "Our next step is to understand the intricacies of why this pattern is occurring; only then will we really have a chance at stopping these future extinctions."
Different herbivores and carnivores provide a variety of unique ecological services, like cycling nutrients through an ecosystem or minimizing local fire risk.
Researchers say their work can help ecologists and conservationists identify the impacts of species losses and prioritize protection efforts accordingly.