Nesting in a Concrete Jungle

By Robyn Graygor

Bird nest under a staircase in The Commons (Photo by Robyn Graygor)

Spring isn’t the only thing that’s calling!

Chirps and songs will become more common as migrating birds search for nesting grounds on the lush outskirts of campus; but for some birds, their year-round homes lie in Purchase’s forest of cement buildings.

Dr. Allyson Jackson, professor of environmental studies, general ecology, and wildlife toxicology, knows of a few feathered friends that find nooks and crannies on roof eaves just as cozy as a tree hollow.

“The house sparrows are definitely common in the kind of urbanized, city area of campus,” said Jackson.

Gianna Papantoniou, a senior environmental studies major, is focusing on house sparrow activity for her senior project.

“They [house sparrows] are very abundant on campus, they’re one of the birds that we all see every day,” said Papantoniou. “From the research I've done, they are successful because they will eat a lot of different things. Like at the Hub if someone drops a French fry, they’re going to go to it.”

House Sparrows gliding through the air outside Durst Humanities (Photo by Robyn Graygor)

These birds can be found nesting all over campus, even in other birds' old nests.

“In the main Quad area, we have cliff swallows that nest on our buildings. The house sparrows' kind of interact with them and will want to use the nests that the cliff swallows create,” said Jackson. “So, they’ll kick the cliff swallows out and use those nests.”

Their success may also be related to the abundance of old buildings on campus.

Samantha Deturris, a sophomore environmental studies major, recognizes the essential role old buildings play as habitats.

“Around here there’s been a lot of deforestation because they’re building that thing, [the senior living facility] so then the birds will find a building that’s just been here forever and are like, ‘Okay let’s just build our nest in here,’” said Deturris.

Birds can’t use just any old building though. They need one with features that mimic a tree.

“They definitely can't use something like the Student Services building which is just glass sided. That doesn’t offer the habitat for them,” said Jackson. “They wouldn’t be able to nest in that because they need the little crevices in some of the older buildings.”

House sparrows sunbathing in the treetops (Photo by Robyn Graygor)

Eliza Wein, an environment and sustainability major at Cornell’s College of Agriculture and Life Science, has studied other urban exploiter species.

“Before the colonization of the U.S., chimney swifts would typically nest in hollow trees or in naturally occurring crevices on a vertical plane. But now they’ve switched almost entirely to chimneys and other manmade structures,” said Wein.

Even pigeons once inhabited a natural environment.

“They’re [pigeons] native to the Middle East, and they used to nest in cliffs and rocky outcrops. If you think of a city, all those tall buildings make perfect places to nest. You would never see a pigeon nesting in a cliff now,” said Wein.

Wein also pointed out the monitoring benefits of having bird species nest in manmade places.

“That’s really great for studying birds because if you think about it, if you’re monitoring a nest in a nest box, that’s a lot easier than one that’s all the way up in a tree,” said Wein. “You can get pretty accurate readings, so sometimes it can be easier and more efficient to study birds that nest in those manmade areas.”

Nest boxes on campus near the Native Plant Garden (Photo by Robyn Graygor)

Around 35 nest boxes were put up at Purchase in 2021 to provide habitat for second cavity nesters which are less drawn to urban nesting.

“I think 30 had nests in them over the course of the summer,” said Jackson. “So that was like 30 new cavities provided to the birds on campus.”

Many of these bird boxes will be filled with migratory birds which will likely arrive sometime in April or May. “We had house wrens use them, some tree swallows, and some eastern bluebirds were the few species that used the nest boxes,” said Jackson.

Before the spotlight lands on the sweet calls of long-distance songbirds, the urban exploiters can share a moment of glory for their savvy adaptation skills.

“I love what I consider urban exploiters because it is remarkable to me the birds that survive in a city or even in our little ‘sort of city’ of the main quad area,” said Jackson.” “They’re really interesting because how are they living doing this? So, I think they deserve some credit.”