Friday, June 10, 2016
A new frog species, a look at songbird population dynamics in the nonbreeding season, a device to simulate sea-level rise, and how urbanization could be affecting inchworms were among the topics presented at the Virginia Commonwealth University Rice Rivers Center Research Symposium last month.
More than 80 scientists and researchers filled a room overlooking the James River to hear 10 presentations and watch two short films at the symposium. The afternoon included a poster session and a tribute to Leonard Smock, Ph.D., director of VCU Rice Rivers Center and interim vice provost of VCU Life Sciences, who is retiring this year.
Smock noted the evolution of life sciences research over the years. “When we started the wetland restoration, the only research going on out there was plant ecology,” Smock said. “Now, it has matured considerably to take in global climate change and rising sea level impacts on the wetlands.”
He credits an investment in environmental technologies for expanding the scope of what researchers can do.
Dong Lee, Ph.D., postdoctoral researcher in the Department of Biology in the College of Humanities and Sciences, has been building electronic devices to assist biologists in their work. In his presentation he emphasized that commercial devices often do not answer the needs for a researcher’s specific work, may be cost prohibitive or could be both. Lee’s solution is to make your own. He demonstrated his DIY approach with a project to build a water pump that simulates sea-level rise in tidal freshwater wetlands.
“I’m thinking a lot of these students and faculty are saying, ‘Hey wait a minute. I can use a sensor to do XYZ. I’m going down to the lab and see if he can’t build that for me,’” Smock said.
Urbanization and the inchworm
Abigail Nelson, a graduate student in the Department of Biology, researched the effects of urbanization on a species of moth called the fall cankerworm, otherwise known as the inchworm.
Cankerworms may be small, but they make their presence known in their eating habits, feeding on the leaves of deciduous trees. Periodic outbreaks can severely defoliate trees. “They eat new leaves on trees, which can be more damaging,” Nelson said.
She wanted to see if urbanization is playing a role in these larger outbreaks – specifically how urbanization affects the parasitic wasp that feeds on cankerworm eggs, effectively suppressing their populations.
“More and more people are flocking to urban areas and there’s more development to keep up with population,” she said. If development is wiping out parasitic wasp populations that keep inchworm populations in check, what does that mean for the trees and forests?
Nelson has long been interested in population ecology, or how species interact with the environment. When she started working in the Johnson Lab, she realized that looking at insects is one key to understanding this. “There are so many of them. You can get a great idea of what’s actually happening in the ecosystem,” she said.
Over two years, Nelson studied cankerworm and parasitic wasp populations at rural and urban sites in Central Virginia, including one at the VCU Rice Rivers Center. She found that in the second year, fall cankerworm abundance declined at every site and identified significantly more parasitoids during that time, but “there was no significant effect of urbanization,” she said. However, her research suggests that the parasitoids may be regulating the fall cankerworm.
What’s ailing the prothonotary warbler?
Biology graduate student Jesse Reese is also interested in looking at species population. Her research is focused on conservation efforts for the prothonotary warbler, a declining songbird species. “My research deals with understanding how populations on the breeding ground are linked to populations on the wintering ground,” she said.
Most of the research on migratory birds happens during the breeding season. To fill knowledge gaps, Reese studied habitat use and quality of the prothonotary warbler’s nonbreeding grounds to get an understanding of their survival over the winter season.
During a month-long trip to the Caribbean coast of northern Colombia earlier this year, she looked at population density and took feather samples from five different sites. Studying plumage is helpful because birds often grow their feathers on breeding grounds so the samples will actually give her information about where specific birds breed.
Next steps will be to analyze the feathers in the lab and see if the birds are coming from the northern or southern part of the breeding range. By comparing populations between seasons, researchers can understand better what factors impact populations. From there, they can establish targeted conservation measures.
A new frog arrives in Virginia
A new species of frog, the Atlantic Coast leopard frog, was discovered in Staten Island, New York several years ago and announced in 2012. That same year, J.D. Kleopfer, herpetologist at the Virginia Department of Game and Inland Fisheries, discovered the species in Virginia.
Kleopfer, a collaborator with the Rice Rivers Center, has been working on confirming the Atlantic Coast leopard frog’s status as a new species in Virginia by analyzing genetic samples, physical characteristics and bioacoustics. In fact, the tip off for him was an unusual-sounding frog chorus—more of a quacking than the warbling chuckle of the Southern leopard frog, a very similar species. He had originally dismissed this observation and it was a year before he revisited what he had heard to confirm this chance discovery.
Based on his experience, Kleopfer had encouraging words for the room, in particular young biologists and conservationists: “You’ve got to be able to pay attention. Get out there and, if you notice something that makes you cock your head a little bit, pay attention to it because you never know what you’re going to find.”