Press Release
Tribute May Go Dark to Protect Migrating Birds

On September 11, 2005, under the auspices of New York City Audubon, several experts in bird migration will be closely watching the Tribute in Light. The columns of light could turn deadly for the huge numbers of birds that migrate over New York City, and the monitors will be on the scene to avert a disaster. Last year's tribute raised an alarm. Unlike events of earlier years, the 2004 tribute showed thousands of birds "trapped" in the lights.

Although the complexities of bird navigation and behavior during migration still present many mysteries, enough is known to cause some worry for the September 11 display. Tall floodlights-such as ceilometers, the searchlights formerly used at airports to measure the distance of clouds from the ground-have been implicated in some notorious incidents. In by far the worst recorded event, which occurred in 1954 near Macon, Georgia, an estimated 50,000 birds (representing 53 species) perished. Ceilometers are no longer used, having been replaced by lasers, but the Tribute in Light is in essence a group of ceilometers.

September is a peak month for many of the 200 or so species that head south over New York City. The majority of these fly during the night, and under certain conditions they can be placed at extreme risk. Birds can be strongly attracted to artificial lights, perhaps because some species use natural light-the stars, the moon-to navigate. When natural light is absent-during cloudy conditions, for example, or when the moon is new-artificial lights can have an amplified and sometimes deadly effect.

Migration for birds is perilous in the best of conditions. Any loss of energy-as when they are flying for a long period of time in a column of light-may cost them their lives. Some light-confused birds remain in the vicinity and in the morning are in danger of colliding with a building. (Windows that reflect are particularly deadly. It has been estimated that in North America an astonishing 100,000,000 birds are killed annually by window collisions.) Or, dramatically, they may even become so disoriented that they fly down the light column, straight into the ground.

There is a long anecdotal history of nighttime bird encounters with man-made structures, especially television and radio towers, lighthouses and skyscrapers. In one incident a well known New York City naturalist, William Beebe, spent the night in the torch of the Statue of Liberty. During his vigil, Beebe witnessed (and was even bombarded by) countless numbers of migrant birds colliding with the torch.

Certain weather conditions seem to be characteristic of disastrous bird kills. These include bad weather along a frontal boundary, low-lying clouds or fog, and sometimes wind currents. The phase of the moon appears to be important as well-a new moon is worst. It is also important to note when the moon is absent from view: this September 11, the moon sets relatively early in the evening.

For the past five years, volunteers from New York City Audubon have checked areas in lower Manhattan for birds that have collided with buildings: they have tallied over 4000 dead or injured birds, representing over 100 species.

Everyone hopes that the 2005 Tribute will be once again be an appropriate memorial to the terrible events of September 2001. New York Audubon will be watching the columns of light and documenting their impact on migratory birds with the help of ornithologist Andrew Farnsworth who will be leading the monitoring effort from the rooftop of a nearby building.