Strategizing species conservation: an undergraduate researcher uncovers the eastern hellbender and its habitat
“Go!” Valentina Alaasam yells while quickly maneuvering out of a shallow, cold mountain stream, with a snorkel bobbing on her head and goggles covering her eyes. She’s carrying a large brown hellbender salamander, an understudied amphibian and imperiled Appalachian native. Fellow researchers are ready to meet her at the shoreline—she only has three minutes to collect a baseline blood sample.
Alaasam, a senior majoring in the biological sciences in the College of Science, started collecting these blood samples as a fellow in the Fralin Life Science Institute’ssummer undergraduate research program. She studies them to understand more about the male hellbender’s unique nurturing behavior, which includes building a nest to protect the eggs. Blood samples will reveal levels of testosterone, glucocorticoids, and prolactin, hormones that have documented relationships with parental behavior in humans, birds, and fish but not so much in amphibians.
The biggest reason Alaasam studies hellbender nesting behavior is to understand why populations are declining. This decline is partly characterized by a lack of recruitment, meaning that not many offspring seem to survive into adulthood. Hellbenders can live up to thirty years, and tend to reproduce at age 7-8. Once the female lays eggs, the males compete for the opportunity to fertilize and guard these eggs through the larvae stage for up to 8 months.
But Alaasam and her team, including her mentor Cathy Jachowski, a Ph.D. student in fish and wildlife conservation in the College of Natural Resources and Environment, cannot safely access hellbender nests under natural boulders without disrupting them. For this reason, the team has built artificial nest sites or big cement boxes, which look like large rocks to mimic the hellbender’s nesting environment. Each box has a tunnel for the nesting hellbender, and a lid for more secure access to him and his nest. Alaasam observes these nests in order to see whether or not the males exhibit guarding behavior, and compares blood samples of males that guard to males that don’t.
Alaasam also studies the morphology—the outward appearance—of the hellbenders. This includes the condition of the hellbender’s body and head. Wounds, for example, may indicate that the hellbender fought over territory, or skin lesions may reflect stressors within the hellbender’s habitat, such as poor water quality.
As such, Alaasam also studies the hellbender’s response to stress. After she grabs one from the stream, she holds them in captivity for 60 minutes in order to repeat the blood samples. She is checking for varying levels of corticosterone, a glucocorticoid hormone that mobilizes glucose and is responsible for the fight or flight response in animals. A steep change in the hellbender’s “cort,” says Alaasam, means they are highly prepared to escape a predator, which would be a normal response to handling and captivity.
“It is considered adaptive for individuals to have a robust ‘acute stress response,’ meaning low baseline levels of cort and a grand spike when faced with a threat,” said Alaasam. “However, when an individual is providing parental care, this response is sometimes attenuated--minimizing the chances that a parent will abandon their nest. An understanding of how hellbenders respond to acute stress while guarding a nest, and how this response changes seasonally, is important for conservation as it will allow us to develop more ecologically relevant management strategies.”
For more than three years, Alaasam has worked as an undergraduate researcher in the Wildlife Ecotoxicology and Physiological Ecology lab, directed by Bill Hopkins, professor of fish and wildlife conservation in the College of Natural Resources and Environment. Not only has she completed her own research project, but in the process she designed and implemented a research proposal, collected and analyzed data from her fieldwork, and successfully articulated her findings in scholarly writing and oral presentations.
“Valentina has done a tremendous job with her undergraduate research, producing publication-quality findings that will advance our fundamental understanding of parental care in wildlife,” said Hopkins. “Importantly, her findings will contribute to the conservation of this imperiled species, one of the most amazing amphibians in North America.”
Written by Cassandra Hockman, communications coordinator for Fralin
Posted October 2014