Dogs, turtles, biology mix for Cornell summer research
Professor of Biology Andy McCollum and his three student researchers received some help this summer from a team of turtle-finding dogs.
This year marked the 16th year of McCollum’s research on the ornate box turtle, which is native in Iowa. It’s also a threatened species due to environmental changes, predators, and poaching.
For the past several years McCollum has focused on discovering more about the turtles since very little is known about the species. He’s specifically digging deeper into understanding why the box turtles are so colorful.
“The goal of our project is to really find out what is ‘sexy’ about ornate box turtles,” McCollum said. “The species is sexually dichromatic, meaning the males are different colors than the females. We see that in birds a lot. Males are more colorful than females, but within both sexes, color varies quite a bit. So I’m really interested in finding out–what do the males that are most reproductively successful look like?”
To do that, McCollum and his researchers need to gather and study as much of the turtle population as possible. His team has used drift fences to capture turtles for a short period of time before returning them to the wild. This year, they were able to work with Montana’s John Rucker and his team of turtle-finding dogs.
“I usually run my dogs about three or four hours in the morning when it’s cool and the turtles are moving and there’s turtle scent on the ground,” Rucker said. “Turtles actually leave a very minute scent trail on the grass, and my dogs lock in on that trail and they are like bloodhounds, they find it and very gently pick it up and bring it back to me.”
Lizzy Ott ’21, John Regis ’20, and Lily Ullenius ’20 are working with McCollum this summer. They enjoyed watching the dogs find 42 turtles in one day. That’s about twice as many as the 2018 team found in the entire summer.
“It was so much fun,” Ott said. “It’s amazing they can do their thing and sniff out these turtles from wherever they are. We now have a ton of turtles to process which is really great.”
The students take the turtles back to the lab to measure, photograph, and collect DNA samples. The DNA will help build the family tree. The researchers use GPS devices to mark each turtle’s location and the turtles are returned right back to where they found them within a day or two.
“The photographs are important because the research Andy is doing, he wants to create a genetic story for all of these turtles,” Ullenius said. “Once we have the blood work for the genetics, we can figure out who it is related to and how many offspring it has had. So we might be able to figure out are these brighter turtles, the ones who are having more offspring or is it, maybe, the more dull-colored turtles.”
The team is also using a UV-Vis reflectance spectrometer, studying the reptiles’ patterns beyond what the human eye can see.
“We are looking to see if the color pattern has to do with reproductive success,” Regis said. “The UV spectrum is another way for us to analyze that. We just hold the spectrometer up against their shell or up against their head. Then we copy the data and put it into a spreadsheet, so it really only takes a few seconds.”
The more data the team can collect, the more answers they will have. They hope their work will help discover more about this poorly understood species, potentially finding answers to keep the threatened population growing. Rucker says this research team is lucky too because they have a great research area in Johnson County.
“I know all of the sites,” Rucker said. “I have worked my dogs on the Wisconsin ornate box turtle sites, I have worked them on all of the Illinois ornate box turtle tracts. This one right here in Iowa is the best in the Midwest, in my opinion.”
While McCollum has worked on this research for 16 years, he has data going back to 1993, when Sandy Rhodes, a geologist at the University of Iowa, first started studying this Iowa turtle population. Sandy’s photographic slides from the 1990s enable McCollum and his students to confirm identifications of turtles first caught 26 years ago.
While 26 years may seem like a long time, McCollum hopes to find someone to carry on the project after he retires sometime over the next decade. He thinks it will take at least another 25 years to answer the question many people ask: How long do ornate box turtles live?