UNO Biology Grad Student Studies Elephant Pregnancies

UNO Grad Student Chelsi Marolf hopes her research will help the declining wild and captive African elephant population. Photo courtesy of Chelsi Marolf

Charlotte Reilly

University of Nebraska at Omaha (UNO) Biology graduate student Chelsi Marolf is studying blood samples from pregnant African elephants to determine differences between successful and unsuccessful pregnancies.

Marolf is analyzing how hormones like progesterone, which thickens the lining of the uterus and helps keep the embryo healthy, and insulin, which controls blood glucose levels, rise and fall during pregnancy. Her study will be the first to look at insulin, glucose, and cortisol throughout pregnancy. Marolf’s research is being funded through a Graduate Research and Creative Activity (GRACA) grant.

“The main goal of my research is to use a variety of hormones, as well as blood sugar levels, to get a better understanding of pregnancy in African elephants,” Marolf said. “Understanding what these hormones should look like in successful pregnancies could help us to increase the chances of successful pregnancies and births in the future.” Marolf said.

She hopes her research and related research will lessen the rapid population decline of elephants in U.S. zoos and in the wild.

According to her GRACA application, “At the current rate, these populations (elephants in U.S. zoos) will be non-viable in approximately 50 years. Moreover, the current population of females is aging, and many have irregular reproductive cycles, making every mating and pregnancy crucial.”

Oftentimes, zoos have to transport male elephants across the country in order to impregnate female zoo elephants. It is difficult to transport such a large animal and artificial insemination does not always work either, Marolf said.

So far, she has run blood samples from three pregnancies.

“In one pregnancy, I saw an increase in cortisol and a decrease in progesterone, but it was one case, so I can’t base any conclusions off of it,” Marolf said.

She plans on analyzing samples from five to 10 unsuccessful and around 10 successful pregnancies, and will look at about 100 blood samples from each pregnancy. She will finish her work in the lab in the spring and complete her thesis next fall.

“The samples I am working with are from the year 2000 to present,” Marolf said. “Zoos take blood samples from pregnant elephants and freeze them, so it’s just a matter of getting those samples.”

Marolf has had to jump through hoops to get the samples but her connections with the Omaha Henry Doorly Zoo, UNO Professor James Wilson and Wildlife Endocrinologist Kari Morfeld have helped. Marolf studies her samples at a lab in the Henry Doorly Zoo and Aquarium with Morfeld.

Marolf’s project is in partnership with the Kansas City Zoo African Elephant Reproductive Conservation Initiative, led by Dr. Kari Morfeld.

Marolf has also accompanied Morfeld to South Africa, where Morfeld researches wild African elephants. She hopes to compare pregnancies in the wild and captivity in order to get a broader understanding of the barriers elephant populations face.

“Our goal is not to just help zoo elephants, but the populations in Africa too,” Marolf said.