Owl Droppings Offer Clues to Climate Change

When thinking of Paleontology, one doesn’t usually think of owl pellets and rodents. But at Terry Labs on the campus of Oregon State University, Rebecca Terry, associate professor in the Integrative Biology Department, conducts palaeoecological research on desert small mammals.   

Terry says, “While OSU has never had a coordinated paleontology program, we have had – and continue to have – researchers who do a wide range of paleo-related work.”   

From palaeobotanical research focusing on the evolution of plants to the study of ancient insects preserved in amber, there are research professionals doing exciting work in many different departments on campus. Terry is a conservation paleobiologist, meaning she applies information from the paleontological record to current conservation and restoration issues, like climate change.  

Research Focus  

Terry’s research looks at the fossils of small mammals and birds to discover how they previously responded to climate changes over time. By looking at which species survived or disappeared across periods of past climate warming, she can get a glimpse at what may lie ahead for species today.   

“If we can then figure out what ecological traits are shared by those who thrived versus those who did not, we can look at the species we have today through that same lens and perhaps better identify which ones might be expected to fare well or fare poorly under future warming scenarios,” Terry said.   

One of the most important of their research findings is the novelty of the flow of energy within the Great Basin Desert ecosystems. The research points to a loss of energy from typical species, which may point to a loss of resources in the area. The animals that can live in a range of habitats and eat a variety of food are doing well, whereas specialized animals are faring more poorly.   

“That is actually counterintuitive, since many of the specialists we have in our system are species like Kangaroo Rats, which are highly adapted to warm and dry conditions,” Terry said. “Thus, one might expect that they would thrive under a scenario of warming and drying – a pattern we do see with past episodes of warming in the middle Holocene some 8,000 years ago.”   

The hypothesis that the team has currently, supported by their work with stable isotopes, is that the decline is due to a habitat change that was brought about by the accidental introduction, in the late 1800s, of Cheatgrass, an invasive species that has spread rapidly over time. The team continues to test this hypothesis.   

Helping with Education  

The thing that most distinguishes Terry Labs from other research is that they work with the fossilized remains of owl pellets. When owls and other raptors eat, they regurgitate the undigestible parts of the small mammals that make up their diet. The pellets will build up in areas like caves, and become fossilized in the sediment. Terry says that owl pellets represent spectacular fossil records.  

Not only does her lab study fossilized owl pellets, but they also use recent excrement as part of their outreach to the community.   

“We love engaging in outreach and opening people’s eyes to how cool owl pellets are and how people can use modern and fossil ‘death-assemblages’ to answer conservation-related questions,” Terry says.   

Part of the outreach involves going to elementary schools and having school-children help dissect the pellets and discover what the owl ate that day. The data gathered in these studies by the children and the team help to show the researchers the biodiversity of the areas. Terry says that owls are fabulous at catching species whose movements humans aren’t able to easily track.   

“Species like shrews, for example” Terry explains. “Shrews are tiny cryptic species that are really hard to catch, so we just don’t know that much about them. But owls eat them and so they turn up in owl pellets much more often than in traps.”  

All of the collected data from these outreach sessions with school children are recorded for use in further research.   

“We keep track of that information in a database as part of our PelletMap project, and are using data generated by kids to create small mammal species distribution maps for the Pacific Northwest,” she says. “The kids and teachers, as well as pellet donors [people who go into caves and find owl pellets], have access to this map and have enjoyed being our partner scientists in generating this knowledge.”   

Paleontologists Aren’t What You Think  

Terry hopes that through her lab’s outreach people will see how important paleontology still is to the world and how much we can learn from history.   

“People often have an outdated dusty image of what a paleontologist is, what they do, and what they look like,” she says. “We also engage in outreach because it gives us an excellent opportunity to actively work to challenge those stereotypes, celebrate the diversity we as a lab represent, and showcase paleontology and paleontologists in the 21st century.”   

Incidentally, if you have a pile of owl pellets sitting around somewhere on your property, Terry Labs would be happy to take them off your hands for use as part of this research. They will even pay for the shipping to get the pellets to the lab.  

For more information about Terry Labs, or to contact them about owl pellets, visit the website.  

By Kyra Young