10/07/2013 05:22 EDT | Updated 01/23/2014 06:58 EST

Why Mass Bird Deaths Occur and How to Stop Them

When 7,500 birds died a few weeks ago at a natural gas flare in New Brunswick, there was shock and dismay among most people who heard the news. Later news stories interviewed various bird experts to try to understand the context -- was this a rare event? How did it happen? Could it happen again? How might it have been prevented? How might this impact overall bird populations?

The fact is, birds do sometimes die in large numbers like this during migration. Really large kills like this one, though, tend to happen under a particular set of weather conditions. The journeys of most North American migratory birds are made primarily at night, and it has been known for hundreds of years that they are often attracted to sources of bright light, especially during overcast and foggy conditions when they are not able to rely on the stars for navigation, as they usually do. Lighthouse keepers often reported in their log books about the hundreds of birds that would circle the tower during foggy weather during peak migration seasons.

Today, lighthouses are only a small fraction of the lighting hazards that migratory birds have to deal with. Tall buildings and towers are two of the more common and lethal types of lighted structures. During the recent September 11 light display memorial in New York City, online videos show hundreds of confused birds passing in and out of the beams of light. In that situation, New York City Audubon worked with the memorial organizers to make sure the lights were turned off when large numbers of birds were drawn in, so they could safely continue their migration. Natural gas flares or flares from other forms of oil and gas production have probably always killed migratory birds at night and when they are relatively high up. Any very bright light source, especially a continuous rather than blinking one, will do so. Perhaps the sad event in New Brunswick will increase monitoring and research to lessen the risks to migrating birds from gas flaring.

As tragic as these incidents are, though, they are a blip in the big picture of threats to migratory bird populations. Seldom mentioned during interviews like those I heard following the New Brunswick gas flare incident is any acknowledgement of the fact that habitat loss and degradation are by far the most serious factors that will impact the future survival and health of most bird populations. Certainly steps should be taken to minimize bird deaths from natural gas flares, wind turbines, collisions with buildings and cell towers, but it will be wasted effort if the habitats these species need for breeding and over-wintering are no longer intact.

It may be easier to convince owners of large buildings to turn off their lights than to ask industries ranging from cattle and forestry to oil, gas, and mining to make sure their business plans include ensuring that ample habitat remains for birds. But just because something is more difficult doesn't mean it shouldn't be done. Without breeding habitat there is no option for a population to maintain itself. It's like a bank account that gets no interest but from which withdrawals are continuing -- the account will continue to get smaller. A massive kill of 7,500 birds in one night at a gas flare is not something to be ignored, and future kills like this must be prevented, especially as the number of natural gas facilities increases. But we cannot afford to lose sight of the fact that the impacts of many large-scale land-change activities result in the loss or degradation of millions of acres of habitat that once supported millions of birds.

Habitat conservation measures are essential and the attention of the conservation movement must not be wholly diverted to dealing with less complicated issues when it's the hard ones that will make the real difference. It's vitally important to the future of bird populations, for example, to ensure that conservation efforts like the interim protected areas of Northwest Territories Protected Areas Strategy are finalized in the next few months.

This area encompasses literally millions of acres of bird habitat. So does the proposal to protect several million acres of bird habitat in the Broadback River Watershed of Quebec that is being advocated by the Grand Council of the Cree and its communities. Or how about the millions of acres of habitat in northern Labrador that the Nunatsiavut government has recommended be placed off limits to development? Bird conservationists should be asking the Government of Newfoundland and Labrador to stop opposing that plan, since those lands support so many birds that migrate to southern Canada and the U.S. Over in western Canada, the Yukon government has opposed a recommendation of their own working group to protected millions of acres of bird habitat in the Peel River watershed. Everyone who cares about birds and the environment should be speaking out in support of these efforts that will protect millions of birds.

Clearly, industries that are needlessly or carelessly killing large numbers of migrant birds need to be held accountable but so do those activities that take away the opportunities for birds to nest and raise their young by removing or degrading their habitats. Most importantly, the large-scale efforts that are underway in places like the Boreal Forest region of Canada and in many other parts of the world that keep that habitat in the ecological bank account deserve our attention and support. Most of the birds that died that fateful night in New Brunswick were likely born in the Boreal Forest region of Canada. They will never have a chance to go back. Let's do our best to make sure that the ones that survive the long migratory flight have a place to return to and raise their young next spring.

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