Female falcon on edge of nest box

A Cliffhanger of a season

Wildlife experts observe falcons’ natural competition for territory

By Lauren Weiss

On a bright April afternoon, the Library Falcon Team made its way up to the rooftop of the W. E. B. Du Bois Library to deploy the falcon cam for an eighth season.

Previously, camera deployment has proven a difficult task that usually takes five or more team members half a day to prepare, secure, and lower the camera arm over the side of the 274-foot-high Du Bois Library. However, with social distancing restrictions in place, Richard Nathhorst ’79, Research Facilities Manager and founder of the Libraries’ falcon program in partnership with the Massachusetts Division of Fisheries and Wildlife (MassWildlife), along with Allan Krantz of Library Technology Systems, devised new block and tackle rigging that made it possible for two people to deploy the camera.

As soon as the camera went live, the falcon community tuned in to watch as last year’s unbanded female began making a depression in the nest box material, readying it for eggs. She laid three over the next couple of weeks. However, an unusual situation unfolded: two male peregrines, only one of which was banded, began visiting the nest box. Although neither the falcon team nor other observers were able to identify which male was the father of the eggs, thanks to some high-resolution images taken with the falcon cam, the team was able to identify the banded male as 21/BU (black over green bands), born at Tufts in 2018. Both he and the unbanded male were seen courting the female, and after close observation, it was apparent they were fighting over the territory.

Endangered wildlife biologist David Paulson G’10 and Hollie Sutherland G ’23, a Tweeter for the @DuBoisFalcons account, note that this behavior is novel to observe, now that peregrines have made a comeback. “Breeding falcon populations were only just restored in Massachusetts in the 1980s, after local extinction,” says Sutherland. “Now there may be competition for territories, which could be seen as a good sign.”

Due to their territorial struggle, neither male hunted for the female, so she abandoned incubation to feed herself, rendering the eggs inviable. Falcon fans were understandably disappointed in the results, but the season had bright moments. Eric Bloomquist G’20, Digital Scholarship Resident at the Libraries, used GIS (Geographic Information System) technology to begin mapping out data points gathered on sightings of banded Du Bois falcons after they have left the Library. Once completed, the interactive FalconMap will be freely available to the public. Additionally, the Twitter pen pal program started by @DuBoisFalcons last year has expanded: Tower Girl (@UT_TowerGirl) from the University of Texas at Austin and the falcons at UMass Lowell (UML_HawkWatch) have joined the Du Bois Falcons and UC Berkeley’s Annie and Grinnell (@CalFalconCam) in sharing all things falcon, including the successful hatching and banding of Annie and Grinnell’s three chicks, Poppy, Sequoia, and Redwood.