About one-third of the birds were alive; I housed them temporarily, one to a container, in brown paper bags. At dawn we saw that the small trees at the tower's base were filled with stunned, exhausted birds. Most would survive their brush with death. More tragic were the still bodies. Most lamentable of all were the living birds with snapped bones or gaping wounds: broken creatures who found the strength to flee my approach. I captured as many as I could...(Apartment Sanctuary, June 1977).

That's how it was a little after midnight, August 30, 1976, just after the CN Tower opened to the public. Since then, however, the CN Tower's management authority has been fully co-operative in extinguishing lights during avian migration periods. They are setting a good example of corporate responsibility for the welfare of our native wildlife.

But still there are other problems in Toronto, throughout much of eastern North America, and in other parts of the world where tall, illuminated structures kill or injure millions of migratory birds each year. There are some simple, practical ways you can help these birds each year.

The Lethal Lure of Light

Over 100 species of birds have been recorded hitting any one of about 150 tall buildings, signs, towers, chimneys and other such structures in Toronto, not including television broadcasting towers, lighthouses and electric generating stations elsewhere in the province.

Many species of birds, particularly the small, insect-eating species such as warblers, flycatchers, wrens, creepers, kinglets, thrushes and vireos, migrate at night. In part they are guided by the patterns of certain star constellations. Lights high above the ground can act as an attraction, pulling the birds off track and causing them either to swirl about until they drop of exhaustion, or to strike the actual structure, usually with dire results.

Weather further exacerbates the problem when fog, rain or cloud cover increases the likelihood that birds will hit tall objects during nocturnal migration.

Thousands of Birds May Perish in The Night

Some tall office buildings and other edifices may only destroy a small number of birds, perhaps two or three on the odd night during the spring or fall. Others may be responsible for destroying birds in staggering numbers. In one September weekend more than 10,000 birds were killed when they flew into floodlit smokestacks at Ontario Hydro's generating station at Lennox, near Kingston.

An estimated 30,000 birds were killed at a TV broadcasting tower in Wisconsin in one night. Sometimes the toll on a single species can be huge. In one night about 2,000 Palm Warblers died hitting a TV broadcasting tower in Florida.

It has not been unusual to pick up hundreds of birds in the streets of downtown Toronto in a single night. On the worst nights, dead and dying birds may be found in alleyways, gutters, side streets, doorways and roof tops throughout the city. The annual toll for Canada may be in the hundreds of thousands.

A Trio of Deadly Problems For Migrating Birds

With particular regard to kills produced by tall buildings in the city environment, there are different types of migratory bird kills and correspondingly different ways of dealing with them.

Primary Nocturnal Kills: Birds killed outright by being attracted to and flying into illuminated structures as they migrate at night.
Primary Diurnal Kills: Birds which, for a variety of reasons, are killed on impact with tall structures during daylight. The numbers involved are usually comparatively minor. Blue Jays and Ruby-throated Hummingbirds are two diurnal migrant species known to hit the reflective glass windows of skyscrapers.
Secondary Kills: This term describes birds which become accidentally trapped in courtyards or other closed in areas at the bases of buildings, and then kill themselves by hitting windows or else die of exposure, starvation, shock or predation. There are significant numbers of secondary kills in Toronto each spring and fall.

What Can Good Corporate Citizens Do?

Primary Nocturnal Kill:
LIGHTS OFF WOULD BE DELIGHTFUL

The simple fact is that huge numbers of birds will migrate at night and light attracts them. Obviously any structure of sufficient height is a potential obstacle, but darkened structures will kill almost no birds on a night when comparable illuminated structures may kill hundreds or thousands.

THE LESS LIGHT THE BETTER WITH NO LIGHTS BEST OF ALL

All effort should be made to reduce or eliminate lit windows, floodlighting, illuminate advertising or other light sources on tall structures during the peak migration periods, from about mid-August to late October, and from about mid-April to early June; and, with regard to time of day, from about midnight until dawn.

Diurnal Kills:
SOME REFLECTIONS ON SAVING BIRDS

Although one can pick up injured birds, there is virtually nothing to be done to prevent birds from becoming confused by reflective windows. Prevention is the only cure. Architects should avoid mirrored glass on tall buildings or on any buildings in open areas or major flight paths.

WHAT CAN YOU DO?

If you work in a tall office building, endeavor to put the lights out in your office when you leave, and close the blinds or curtains. Many office lights can't be switched off individually, or must remain on to assist maintenance or security staff, but usually there are curtains and blinds that can be pulled. Encourage fellow office workers to do the same.

Each spring and fall try to post notices on bulletin boards, in company or union magazines or other publications or through interoffice memos to remind management and employees to turn out lights and close curtains and blinds each evening.

GET THE WORD OUT TO PUT THE LIGHTS OUT!

• Management should endeavor to instruct occupants to leave offices dark at night or, if that is not feasible, to close curtains and blinds. Incentives can be provided for compliance.
• Public relations departments should promote interest in darkening the Toronto skyline and tell the media, customers, staff and others why it is being done.
• Workers who pick up stunned birds should keep them calm and quiet by placing them in unwaxed, brown paper bag temporarily. If there is a wildlife rehabilitation facility nearby, the birds can go there. The Toronto Humane Society will take in birds that have hit windows as well.
• Avoid putting indoor plants close to broad expanses of plate glass.
• If you see a tall building that is illuminated during spring and fall migration, contact the building's management authority, explain the situation and request that the lighting be eliminated during critical periods. Many management authorities are entirely co-operative once the situation is explained.
• Never use searchlights for promotions on wet, foggy or drizzly nights, particularly from about midnight to dawn, during the spring and fall.
• If you are involved in designing tall structures, avoid having large, bright areas of illumination on them, particularly on the higher levels.

Secondary Kills:
A CHANCE TO RESCUE THE BIRDS

The primary factor in these kills is the complicated design of some courtyard areas at the bases of tall buildings. Birds are confused by reflections in glass, or the appearance of indoor foliage behind large, plate glass windows.

Short of blocking the windows, there is little that can be done other than trying to catch the birds before they 're seriously injured and moving them to natural habitats.

CAN YOU REALLY MAKE A DIFFERENCE?

Yes. The problem of nocturnal migrant bird kills is little known. Cleaning and security staff often sweep up dead and dying birds before office staff arrive in the morning. Even when birds are present, they are usually overlooked by most people. There are now disturbing indications that populations of our native songbirds are in decline, songbirds whose presence on our planet make life more pleasant in many ways for all of us; songbirds with which we can share an environment that is as much theirs as ours. We can help them by trying to keep them safe as they migrate overhead, unseen amid the stars in the darkness of spring and autumn nights.