Interns Learn Appreciation for Reptiles

Michelle Chapman, left, and Manuel Colomba enjoyed
internships with reptiles.


Handling lizards or turtles may send a chill down your spine. But it’s all in a day’s work for two summer interns at Iowa State University.

Michelle Chapman, senior in animal science at Prairie View A&M University in Texas, and Manuel Colomba, a high school junior at Guamani Private School in Puerto Rico, have been working this summer in the lab of Fred Janzen, professor in ecology, evolution and organismal biology. Janzen and Dan Warner, post-doctoral research associate, mentored them and Tim Mitchell, a graduate student, also mentored Colomba.

Chapman and Colomba were two of 14 students who participated in the George Washington Carver Internship in the College of Agriculture and Life Sciences.

Chapman worked with Anolis lizards in order to determine why they lay only one egg at a time. Her hypothesis was that a single egg reduces moisture competition among eggs and enhances the quality of offspring.

“I’m interested in learning why these lizards lay one egg at a time because most reptiles lay eggs in bulk,” she said. “We placed the eggs in treatments and when they are hatched we analyze various factors to see if we can determine an answer.”

“Based on preliminary results, solitary incubation does not benefit offspring any more than does aggregated incubation. This result can lead to research on other factors in the future,” Chapman said.

Colomba’s internship was with painted turtles to see how temperature and size of hatchlings affects performance when competing for food.

“By placing a cricket in a cage and watching turtles compete for food, we can see how temperature and size affect their performance. We watched two to seven turtles at a time and identified the most competitive turtle,” Colomba said.

“We’re finding out that size doesn’t matter when it comes to competition. Some of the smaller turtles are most competitive,” he said.

He also studied temperature, which determines the sex of a turtle. Turtles that are incubated at higher temperatures will be females and tend to be larger than males, Colomba said.

When they weren’t researching, the Carver interns participated in a wide variety of events and trips. “My favorite trip was to the Henry Doorly Zoo in Omaha. I really enjoyed seeing the big cats exhibit and taking the chair lift over the zoo,” Chapman said. “The nicest thing about the GWC Program is the experience with research and getting to know all the people,” Colomba said. “In Puerto Rico, we don’t have these programs.”

Champman said, “It’s going to be bittersweet leaving, because I don’t get to see the hatchlings grow. I learned a lot and the people I worked with were very warm and welcoming. I enjoyed getting to know the people and if you don’t know what you want to study or do career-wise, the program gives you another perspective or option to consider.”

The George Washington Carver Internship Program is for undergraduate and high school students who will enhance diversity at Iowa State University and are interested in research in agriculture-related fields. Interns conduct research and participate in various events and seminars. Over the past 16 years, there have been more than 300 students to visit Iowa State as a part of the program, which is funded by the College of Agriculture and Life Sciences and other sources. Approximately 20% of these students have enrolled at ISU for undergraduate or graduate studies. For more information, visit: