“Lights Out at Home”

Good Strategy or Bad?

It asked on a listserv where experts post on bird collision matters whether there is any research about lights and residential bird collisions. This question raises an important question about the interrelationship of science and bird safety advocacy.

We must base what we do on the best science we have.  On the one hand we know residential windows cause 200 million bird deaths and we have proven systems to prevent those deaths.  We also know lights cause bird collisions in well-lit buildings in certain locations.  Perhaps we can infer that the same applies to residential lights?

Let’s say a club warns its members that migration is starting and that they should protect migrating birds.  They give their members two options to protect the birds: 1. turning off your home lights or 2. installing a permanent bird window collision prevention system.

Which one will most members pick – It’s easy – “I’ll turn off my lights, it won’t cost me anything and I don’t have to install anything on my windows.”

When we offer the public two options they implicitly think that they are equally effective.

Are they?

It is not good enough to say “everyone should do both.”  They won’t – most people will do the easiest thing and their guilt will be assuaged. (Guilt is about the only motivator we have.)

But what if turning off home lights is very effective,  a little effective or hardly effective at all?

If I can convince 50 people to turn off their lights, but I can only convince 5 people to install a permanent window collision prevention system, should I go for the 50 or the 5?

Based on the threat ratings systems at ABC if I install a very effective system I can be pretty confident of saving 1.9 birds per year per house or 9.5 birds.  Will turning off porch lights for three weeks in spring and fall save 9.5 birds at those 50 houses? — one bird at one out of every 5 houses?

Looking at it another way, the “lights out advice” may mean that those 5 people who were willing to install a permanent system have changed their mind and will not bother to install it.  If the “lights out at home” strategy has no measurable benefit, then the “lights out at home advice” would end up killing 9.5 birds.

So should bird clubs advocate turning off lights in homes, inferring from the PNAS study and others that it will be effective, even if the effect is that systems with a higher degree of scientific certainty are not installed?  

I posted the question about whether there is any research about lights and residential bird collisions because it raises an important question about the interrelationship of science and bird safety advocacy.

We must base what we do on the best science we have.  On the one hand we know residential windows cause 200 million bird deaths and we have proven systems to prevent those deaths.  We also know lights cause bird collisions in well-lit buildings in certain locations.  Perhaps we can infer that the same applies to residential lights?

Let’s say a club warns its members that migration is starting and that they should protect migrating birds.  They give their members two options to protect the birds: 1. turning off your home lights or 2. installing a permanent bird window collision prevention system.

Which one will most members pick – It’s easy – “I’ll turn off my lights, it won’t cost me anything and I don’t have to install anything on my windows.”

When we offer the public two options they implicitly think that they are equally effective.

Are they?

It is not good enough to say “everyone should do both.”  They won’t – most people will do the easiest thing and their guilt will be assuaged. (Guilt is about the only motivator we have.)

But what if turning off home lights is very effective,  a little effective or hardly effective at all?

If I can convince 50 people to turn off their lights, but I can only convince 5 people to install a permanent window collision prevention system, should I go for the 50 or the 5?

Based on the threat ratings systems at ABC if I install a very effective system I can be pretty confident of saving 1.9 birds per year per house or 9.5 birds.  Will turning off porch lights for three weeks in spring and fall save 9.5 birds at those 50 houses? — one bird at one out of every 5 houses?

Looking at it another way, the “lights out advice” may mean that those 5 people who were willing to install a permanent system have changed their mind and will not bother to install it.  If the “lights out at home” strategy has no measurable benefit, then the “lights out at home advice” would end up killing 9.5 birds.

So should bird clubs advocate turning off lights in homes, inferring from the PNAS study and others that it will be effective, even if the effect is that systems with a higher degree of scientific certainty are not installed?  

Published by birdfriendlyyards

I am dedicated to helping birds. I concentrate on making sure they have enough to eat -- and thus promote native plants, and making sure our yards are safe for them -- and thus promote the use of systems to protect birds against deadly window strikes. I worked for national environmental organizations, in the U. S Senate as Chief Counsel of the Senate Agriculture Committee and as a policy adviser in a presidential campaign.

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