Tuesday, September 18, 2012

"Open Air" a Possible Danger to Migrants and an Opportunity to Learn More

Open Air is a public art display by Canadian artist Raphael Lozano-Hemmer that will be presented September 20 through October 14. The main feature of this display is a series of powerful robotic searchlights that will respond to input from people's mobile devices to create light sculptures that will illuminate the night sky over the Benjamin Franklin Parkway in Philadelphia. But, despite the artist's and his backers' best intentions, the timing of this display could not be worse. Late September is the peak of fall migration, when thousands of birds will be flying south through the night sky. Recent evidence has shown that migrating birds can become severely disoriented, even to the point of exhaustion and death, by artificial lights on their migration, and Open Air presents a danger to these birds. Upon learning of Open Air, Audubon Pennsylvania has been working with Lozano-Hemmer to lessen its impact, and in the process has been given an opportunity to further study the effects of artificial light on migrating birds.

Science is just beginning to understand how birds navigate during their complex migration. Songbirds and other smaller species of birds migrate at night (as opposed to raptors and waterfowl, which can be seen migrating during the day). When flying at night, birds use the light from the setting sun, moon, and stars as reference points. They are instinctively drawn to sources of light, including the artificial lights of cities and urban areas, and become reluctant to leave these areas. Floodlights and searchlights can be especially dangerous to migrating birds. The birds fly into the lights and, driven by instinct, refuse to leave, essentially becoming "trapped" in the light. The birds will continue flying, often to the point of exhaustion. Disoriented birds also run the risk of dying from collisions with windows and buildings. This was seen in New York City at the Tributes in Light display at the Ground Zero Memorial in 2004.

There is still a lot to learn about the dangers artificial lights pose to migrating birds and most people are completely unaware of it. In fact, most people are unaware of the fact that birds fly at night during migration. The artist Raphael Lozano-Hemmer was among them when he created Open Air. By the time Audubon Pennsylvania learned of the display, it was already too late to reschedule it to a time after the peak of fall migration. Since then Lozano-Hemmer has been working with Audubon to lessen Open Air's impact on birds, and Audubon has taken the event as an opportunity to learn more about artificial light's impact on bird migration.

Working with three scientists who have extensive experience researching how birds respond to light, Dr. J. Alan Clark (Fordham University), Dr. Susan Elbin (NYC Audubon), and Dr. Chris Sheppard (American Bird Conservancy), Audubon Pennsylvania will have a three pronged monitoring system in place during Open Air's displays. Volunteers and birders will be on the ground looking for birds through their binoculars and spotting scopes, keeping a close eye for any birds trapped in the beams of light. Acoustic recorders will also be in place to track any of the calls birds use when migrating. A small-scale avian radar system, MERLIN XS25200e Avian Radar System, will also be used to track the movement patterns of individual migrants, including altitude and flight direction, as well as the total number of migrants passing through its radar beams. The objective of using this radar equipment is to quantify the magnitude, direction, and altitude of migrants over Philadelphia. In addition to the possibility of helping understand any potential impact of the Open Air installation on migrating birds, this deployment will be one of the very first studies showing how birds respond to urban landscapes during migration and help understand the magnitude of migration through a major metropolitan area. Such information is sorely needed to help scientists and urban managers understand and mitigate the impacts urban landscapes have on migrating birds.

Following Audubon Pennsylvania's recommendations, Lozano-Hemmer has planned several precautions that should lessen the impact Open Air will have on migrants.  The light show will feature regular black-out periods when no lights are lit, so that any trapped birds have an opportunity to fly away. The display will also refrain from using static light beams since birds are probably less likely to become trapped by moving lights. The light beams will also avoid buildings and other structures that birds could collide with. The engineers operating Open Air will be in contact with the Audubon staff and volunteers on the ground so the display can be shut down if any birds are reported as being in danger.

Hopefully these measures will prevent any birds from dying. But at least the situation has given scientists a unique opportunity to study artificial light's impact on birds and a chance to better understand what happens when birds migrate through urban landscapes. The information these scientists hope to gather during this project may lead to significant advancements in the field – and the stakes are very high for migrating birds and for people, plants, animals, and ecosystems that depend on the birds.

You can help. Audubon Pennsylvania is looking for volunteers who will be able to monitor the area for birds during Open Air. They are also seeking donations to cover the costs of the radar and sound equipment. You can learn more on their website.

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