Ravens at Wellesley
Two common ravens nested at Wellesley’s Science Center in spring 2014.
The ravens chose Wellesley College most likely for its cliff-like buildings in a productive landscape. The Science Center, surrounded by shrubs and trees, sits alongside an open, sometimes damp meadow. From where "Pauline" and "Henry" made their nest high in a partially glass-enclosed fire escape on the sunny side of the building, their view included Galen Stone Tower, Houghton Chapel, more trees and open spaces, and Lake Waban.
Wellesley College founders Henry and Pauline Durant located their college for women in a clean, beautiful, inspiring landscape and emphasized science in this environment: astronomy, botany, psychology, zoology, and so on. That was trailblazing in the 1800s. "We still do exceptional science here in the lab and in the field," notes Rodenhouse. The ravens nesting at Wellesley offer a unique opportunity to add to scientific knowledge."
The ravens' coming to Wellesley is emblematic of the re-wilding that has taken place in New England over the past century. Nature is resilient. Other wild animal species now living with us (and sometimes spotted on Wellesley's campus) include American turkey, beaver, pileated woodpecker, red fox, and white-tailed deer. This a positive message for those concerned about the environment. These large black birds may seem formidable but present no threat to people.
Through a network camera, Wellesley live streamed the birds' behavior at the nest 24 hours per day from April 7 until May 30, when the the nestling fledged and the family left the nest. The video feed was also recorded for scientific purposes. The ravens' choice of a nesting spot near existing lighting made the nest visible to the camera even at night. Student researchers will help analyze and interpret the data, with Rodenhouse as their advisor. "We expect to publish a short summary of our observations in the August issue of Bird Observer," he said.
Rodenhouse's own research focuses on the effects of climate change on migratory songbirds. With fellow researchers, he has been intensively monitoring a population of black-throated blue warblers (Setophaga caerulescens) that breed across a 600-m elevation gradient within the Hubbard Brook Experimental Forest of north central New Hampshire.
In the Northeast, ravens have been birds of the remote wilds until fairly recently; they have been increasing in abundance in this area since the mid 1970s.
We cannot be sure how old the raven pair is, but a couple of factors suggest they may be young, explains Rodenhouse: The population of ravens is growing and expanding, so the proportion of young in the population is growing. Ravens seem to be monogamous and have large territories. Older birds nest on the same territory, often in the same location, so it is the younger birds that expand into new areas. Last, younger birds typically lay fewer eggs than experienced adults. The typical clutch size is five; Pauline laid two eggs and only one was viable.
What Did We See?
As the video above suggests, those who tuned in to the Ravencam saw up close the singleminded care the parents gave the egg and hatchling. We saw the rapid growth of a creature that could not hold its head up into one that tested its wings and flew away.
Folks on campus could sometimes hear the ravens in and around their nest, and some have observed them around campus since the baby fledged.
Ravens are territorial and monogamous omnivores and predators. They will dive in a dumpster, kill a small mammal, raid another bird species' nest, or catch grasshoppers in a meadow while foraging cooperatively.
"I have observed their antics in the wilds of New Hampshire," says Rodenhouse, adding, "Ravens are highly social, creative, and love to have fun." We did not see as much of that as we might have, as only one of the two eggs hatched. We did see the youngster increasingly explore the confines of the nest and tussle with the twigs as it prepared to head off into the world.