Pitt to adjust ‘victory lights’ for the birds
Beams can disrupt migration patterns
The powerful blue beams that shine straight up from the top of the Cathedral of Learning signal sports wins for University of Pittsburgh teams, but the “victory lights” also can disrupt migrating birds and cause them to crash into buildings.
The pillar of blue light radiating from the top of the 535-foothigh National Register of Historic Places landmark may block the paths of birds migrating at night, confusing them and trapping them within the beam and potentially leading to fatal collisions.
The Audubon Society of Western Pennsylvania announced a compromise solution Friday — it involves turning off the lights for periods during the night — that Audubon and Pitt officials believe will permit the birds to fly by the Oakland campus and complete their migrations.
The number of birds that have died on the sides of highrises on the Pitt campus and surrounding area is not known. But colliding with tall buildings is the second-leading cause of death among birds in North America, behind attacks by domestic and feral cats. Those causes and road deaths are believed to be responsible for 95 percent of bird deaths.
“During bird migration, many species travel at night. These birds may become trapped and disoriented in the vertical beams of light. As the birds become trapped, there is increased risk of collisions and bird death,” said Rachel Handel, Audubon spokeswoman.
Football season, unfortunately, corresponds with the height of the fall migration.
“In perfect conditions, according to the Cornell Lab of Ornithology, millions of birds could be moving regionally during peak migration time, throughout the night,” Ms. Handel said.
The hazard was brought to light by Kate St. John, a Pittsburgh bird watcher whose blog “Birds Outside My Window” recently compared the Cathedral of Learning lights to the Tribute in Light at the 9/11 memorial in New York City.
Last fall, a journal of the National Academy of Sciences published a research paper that explored the phenomenon of hundreds of thousands of nightflying birds being irresistibly attracted to and disoriented by the iconic art installation, which each year features two blazing columns of light rising from the former location of the World Trade Center on the anniversary of the Sept. 11, 2001, attack on the twin towers.
It has long been believed that migrating birds navigate at night using the illumination of stars as reference points. Until last year, wrote the authors of the study, no research had quantified avian responses to powerful ground-based lights in urban areas.
“This single light source induced significant behavioral alterations in birds, even in good visibility conditions, in this heavily photo polluted environment, and to altitudes up to 4 kilometers,” a team led by Kyle G. Horton, a biologist at Cornell in Ithaca, N.Y., wrote in the journal.
During the study periods, which occurred on seven consecutive 9/11 anniversaries, an estimated 1.1 million birds were influenced by the lights.
“When the installation was illuminated, birds aggregated in high densities, decreased flight speeds, followed circular flight paths and vocalized frequently,” the report said. “Simulations revealed a high probability of disorientation and subsequent attraction for nearby birds, and bird densities near the installation exceeded magnitudes 20 times greater than surrounding baseline densities during each year’s observations.”
When the lights were extinguished, the behavioral disruptions disappeared, suggesting the migration hazard could be eliminated by simply turning off the lights.
Following Ms. St. John’s observation, staff from the local Audubon chapter notified Pitt administrators of the potential victory light problem and consulted with New York City Audubon, which assisted in managing the Tribute in Light.
“The university quickly indicated its willingness to cycle the lights on for 45 minutes, then off for 15 minutes,” Ms. Handel said. “The lights will be monitored and adjustments made as necessary.”