In only her first year at Vassar, Assistant Professor of Biology Megan Gall is researching local songbirds in the emerging field of sensory ecology, which studies how an organism senses and interprets its environment.
It’s the same basic question philosophers from Plato to Descartes have posed, only now focused on animal and not human perception.
Gall explained, “The way animals perceive the world, or more accurately their sensor information, is affected by the kinds of environment they live in.”
Gall cited the following examples as ways in which one can think about the relationship between environment and sensation.
Sound has a difficult time traveling far in heavily wooded areas, where hard surfaces bounce off noises and the thick foliage swallows up any high frequency tones.
Due to this interference, organisms, like certain songbirds living in thick woods, are evolutionarily adapted to sing in long, pure low-frequency registers that travel farther.
But these same songs would not necessarily work for a group of birds living outside of a forest in grassland. In an open space like a prairie, blowing winds will distort long low-frequency notes. So birds in these environments have evolved to sing in shorter, staccato-like high-pitched trills.
Alongside a team of five student lab assistants, Gall works in the lab and on the Vassar Farm and Ecological Preserve collecting data precisely on the auditory systems of different organisms.
As part of one project, student assistants set up cages baited with sunflower seeds around the farm. They will then capture birds and take them back to Olmsted Hall for research.
In the lab, Gall and her team can use electrophysiology, a noninvasive technology, to determine the exact the range of sounds a bird is capable of hearing.
After no more than typically 24 hours in the lab, the bird is tagged with an identifying aluminum band on its foot and released back to the farm.
Stationed at one of the four seed feeders distributed on the Farm, Arick Wong ‘14 and his fellow assistants will then observe the birds in their natural habitat.
Gall and her assistants are investigating whether or not birds hear and sing in different frequencies.
Strapping on snowshoes, they sometimes even go into the farm during the cold months. Not that this bothers Wong, who journeys into the farm once a week.
“I actually prefer working in the winter because due to snow and cold temperatures, birds spend more time foraging and eat more for energy,” said Wong, adding, “In the winter, I can refill a feeder and two minutes later be surrounded by a million chickadees literally two feet away from me.”
Wong is joined by four other team assistants, Ali Ehrlich ‘15, Tymon Dickson ‘15, Jacob Damsky ‘15 and Aaron Kim ‘16.
Gall obtained her Ph.D. at Purdue and her M.S. at California State University Long Beach. Her early research with sensory ecology began with organism’s visual systems. Later, however, she turned to the realm of acoustics. A percussionist, Gall expressed the importance music has had in her life. In graduate school, she was a member of a band called “Boo Radley and Tequila Mockingbirds.”
While Gall focuses mainly on the auditory systems, sensory ecology is broadly interested in all the different ways animals perceive their surroundings.
Scientists have studied the traditional senses that we rely on like sight and hearing, but also sensory systems completely foreign to humans.
Compared to other animals, our sensory systems can seem rather limited in scope. Certain birds can perceive ultraviolet light, while some fish can sense electrical currents in the water.
Other species can even intuit the earth’s magnetic fields, which acts as a sort of internal compass during seasonal migration. These gaps in the human sensory experience can lead to the false assumption that organisms must necessarily perceive the same world we do.
“We’ve been very biased for a very long time that what we see another animal sees, what we hear another animal hears,” said Gall, “but they may be producing things that we have no perception of.”
Wong explained how biologists can construct an understanding of an organism’s world through the concept of the umwelt, a German word meaning literally “self-centered world.”
Wrote Wong, “[Umwelt] refers to an animal’s worldview based on their surroundings and sensory systems. Studying hearing, I think a lot about how birds hear and respond to each other and what implications this can draw for their behavior and their ‘umwelt.’”
Introduced in the early nineties, sensory ecology borrows elements of various different scientific fields and disciplines.
“Sensory ecology is a very integrative field, so we take a little bit from lots of different places and integrate theories that don’t often talk to each other,” said Gall.
She maintains a WordPress blog where she, her assistants and the students in her classes contribute original content about exciting developments in sensory ecology.
The blog is designed to train students to write about science in a language that is accessible to a general audience.
“I think it is very important, especially going forward, that we are able to communicate science to people who are not scientists. I think there is a trend in this country for scientists and the public to be very divided,” said Gall.
Recent posts have talked about new research on snake navigation, chemical signals used by ants during foraging, and the mating calls of crickets.
Sensory ecology is particularly well-suited for Vassar’s liberal arts model, according to Gall.
She said, “It’s great for someplace like Vassar because I can take students from Science, Technology and Society, I have Neuroscience and Behavior, people who are interested in these different things, I think, can find a project here that will fit with their interests.”
Gall hopes to build on her lab’s work and expand into new territory outside the Farm. She said that they had captured about 40 birds thus far, mainly black-capped chickadees, tufted titmice and white-breasted nuthatches.
Gall is not interested in every bird song, however.
“We’ve also caught a number of woodpeckers and sparrows, but we let those go right away,” she said.