The ecology, migration and behavior of strange creatures
North Dakota State University’s biological sciences department hosted a faculty promotion presentation Sept. 6. The presentation was given by Erin Gillam, an associate professor of biological sciences, who has done extensive research focusing mainly on bats and their communication signals.
Gillam’s presentation was about her research on bats, degus and red-winged blackbirds. She also went into detail on the many projects that have been created by either her or her students on these animals.
Gillam’s main focus was about the ecology and conservation of bats in the northern great plains region of the U.S. and in North Dakota. Within the state of North Dakota there are 11 species of bats, though the Red River Valley has the lowest diversity among the species. “Most of the species we have here are only present during the summer. They migrate in through summer and migrate out somewhere else though we don’t exactly know where most of the time”, Gillam said. “Although we do have a couple of species from past work in my lab that we have documented over the winters in the state. They live in the caves and the rock crevasses that you find out in the Badlands of western North Dakota.”
In 2015, the northern long-eared bat was listed as federally threatened. Though Gillam didn’t go into too much detail on this particular species of bat, she wanted to show how it has brought more attention to trying to understand aspects of the ecology of these animals and how it can improve management plans. “There really is a need for that because bats in North Dakota face a variety of threats. First, you have just generalized habitat loss that is a problem.” Some of the examples of habitat loss in North Dakota, especially in the eastern part of the state, is massive conversion to agriculture and draining of wetlands which impact the availability of habitats for bats.
“Another thing is wind energy. We have a fair amount of wind energy in North Dakota. While they’ve been getting at a solution for wind energy, there are still lots of bats that die every year at wind turbines.” According to Gillam, people use to think that the bats would fly into the turbines at night. She further explained that what actually happens is that at the tip of the turbine the air pressure is lower so when they fly through, the changing pressure causes their lungs to explode.
“The third and in some ways the scariest problem is white-nose syndrome, a disease of hibernating bats that gets them in the winter. It has been responsible for six to seven million deaths of bats since 2006.” White-nose syndrome was originally found in upstate New York and is predicted to have been brought over from Europe. It was recently discovered in North Dakota in June at the Knife River Indian Villages. “There’s a lot of concern about how to manage the bats that are here. Not only for this disease, but to identify what they need to be successful in terms of habitat and resources.”
Gilliam then moved on to discuss the projects that have been conducted in her lab over the past five years. The first project looked at how bats used habitats and what habitats they would select. The purpose of the project was to get a generalized idea of where bats prefer to live. Another project focused on whether bats used the Missouri River as a migration corridor since it’s been predicted that bats use coasts and rivers to help them find their way. The last project Gillam talked about was how they used acoustic monitoring to understand long term population changes in bats throughout North Dakota.
The next part of her presentation shifted to the behavior of degus which are small rodents that live in central Chile. The project with the degus was worked on by Nick Johnson, one of Gillam’s master students. The main focus of the project was how degus behaved towards predators. The research expanded off of what was conducted in the 1980s when researchers established plots of land. Some of the plots where open to the environment while the other plots were free of predators. The predator-free plots had fencing all along the edges to keep out ground predators and fencing above to keep out aerial predators. The degus in the predator-free plots could move to the exposed plots as well.
Throughout the 30 years, there have been a variety of studies that have been done to look at how the degu populations living in these predator-free plots differ in physiology, morphology, and behavior from degus that are in the open plots. Johnson used an open field test which gave the degus the option to hide from prey or run around the inside of the arena. He found that there was no difference among the degus from the controlled plots and predator-free plots.
There is some rationale behind why there might not be any differences between the groups. One thought is that 30 years is not enough time to change the behavior of the animals. Another reason is that the degus are still getting exposure to predators since they can move from the predator-free plots to the open plots. The last possibility could be that the test just wasn’t good enough.
The last part of Gillam’s presentation was about the migratory ecology of red-winged blackbirds. The project with these animals started in 2009 with data collected from 2010-2013. The purpose of this research was to track the migratory movements of male red-winged blackbirds. A light level geolocator which is a lightweight tracking device helped track and record the location of the birds. From this project, they were able to see the movements of the birds and the estimated migratory pacts.
Gillam received a Ph.D. at the University of Tennessee: Knoxville in ecology and evolutionary biology. She came to NDSU in 2009 and since obtaining her associate professors position, has published 14 papers and served as faculty senate president.