Students find link between plants, bird migrations

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A. Sue Weisler

Assistant professor Susan Smith Pagano, left, and students Charmaine Merchant, Cassie Gould and April Meier examine wild fruit specimens to measure energy, fat, fiber and protein content to help determine if migratory birds are eating healthy.

Just after sunrise several mornings each spring and fall, Susan Smith Pagano, an assistant professor in RIT’s Thomas H. Gosnell School of Life Sciences, and her students head to Braddock Bay Bird Observatory on the south shore of Lake Ontario. They catch small songbirds in nets, band them, take blood samples and release them after a quick examination.

This is the third year blood samples 
have been studied in hopes of determining whether newer, invasive species of fruit-bearing plants are causing nutritional 
problems for the birds. Many species of migratory birds have seen a decrease in population in the last three decades, she says.

“We’re worried the birds may not be able to put on enough body fat to continue migration,” says Smith Pagano. “Native fruits tend to be higher in energy than those of invasive shrubs.”

In the fall, migratory birds by the thousands flock to Braddock Bay for a rest after crossing Lake Ontario. They come from breeding grounds north of the lake and 
stop there before continuing their journey south to Florida or even South America.

“It’s an important migration spot for birds,” Smith Pagano says. “And they need a lot of fuel and energy to make the trip. 
So they’ll stop and refuel along the way.”

Those not hearty enough to make the journey could die trying, or not travel as far. 

Smith Pagano, who received her Ph.D. for studying the nutrition of birds in Rhode Island, is focusing on small songbirds, 
including warblers, thrushes and sparrows. Her biology students examine blood 
samples, studying its proteins and lipids and the caloric energy of the berries birds eat.

Laboratory Science Technology students at RIT’s National Technical Institute for the Deaf, under the guidance of Smith Pagano’s husband, Associate Professor Todd Pagano, analyze the samples of fruit collected that the birds may eat using multidimensional florescence spectroscopy.

“We’re trying to look at the molecular content of wild fruits,” Pagano says. He says climate change could help invasive species thrive in this region, overtaking native fruit-bearing shrubs. And climate change may also alter the times when fruits ripen, which could force birds to miss the best food sources, especially if bird migration times are also shifting with climate change.

“We’re trying to correlate the wild fruits they eat with the nutrients in the food. Phenols, chemical compounds that can contribute to antioxidant protection, are measured among other indicators,” Smith Pagano says. “It’s a nice interdisciplinary collaboration.”

In September, Smith Pagano received a grant from the American Wildlife Conservation Foundation to help continue their research. “People can use this information for managing wildlife habitats and conservation efforts,” Smith Pagano says. They hope to develop fact sheets about the quality of different shrubs and recommend adding specific plants to increase the food quality found in birds’ natural habitats.

Undergraduate students have presented their findings at local, regional and national conferences as a way to disseminate their research. And their findings have been 
published in Northeastern Naturalist 
and alluded to by the Audubon Society. 

Bird food

Recommended native fruits: Arrowwood, Silky Dogwood, Gray Dogwood and Red Osier Dogwood

Invasive species for birds:
 Common Buckthorn, Bush Honeysuckle and Multiflora Rose