Do patterns scare away birds?

DEAR READERS: At a holiday event recently, a party guest approached me with exciting news. He had solved the problem of birds pooping on his picnic table and wanted to share the secret.

He has a beautiful redwood table situated under a massive oak tree, but alas, the table is a favorite target of neighborhood birds doing what birds do. He’d gotten tired of cleaning the mess, and decided to cover the table with a black-and-white checkered cloth, figuring that the vinyl fabric would be easier to clean than the table.

Within a few days, he noticed that there were hardly any droppings on the tablecloth, and after about a week, he didn’t even see any birds in the tree above the table. He decided that the checkered pattern must be scaring the birds.

Before he invested all of his money in a new checkered cloth bird deterrent scheme, I told him I’d do some research to see if his discovery was genuine.

I could find no evidence that manufactured patterns bother birds. Although some animals’ fur, feathers or scales have patterns that make them appear larger or more threatening, there’s nothing really frightening about a nice check print.

I looked into the use of dazzle camouflage once used by the Navy on ships with great effect. The most common patterns used were bold black-and-white stripes. When seen from a distance through a submarine periscope, the stripes made it difficult to tell if a ship was coming or going or the speed with which it was moving.

In modern warfare however, radar and sonar have eliminated the need for visual sightings and calculations. Birds, with their superior eyesight that allows them to track both moving and fixed objects even while in flight, don’t seem confused by patterns.

The color of the tablecloth might be important. Studies have shown that birds have a dislike of the color white, and when given the choice of differently colored cars to poop on, they most often choose the red car and leave the white alone. There’s a small chance the white checks are disconcerting to them.

Rather than an enchanted tablecloth, I think there’s probably something else going on that has sent the birds elsewhere. One could be the arrival of colder weather, prompting the birds to move to other sites nearby. They may have discovered a new source of food. Or the man’s reclaiming of the table for family gatherings could have frightened the birds away.

If you want to try the tablecloth deterrent, I’d recommend using a solid white tablecloth and scattering some rubber snakes around. If you do this, let me know how it works.

DEAR JOAN: Is it true that crows are frightened by a fake, stuffed crow? My friend says she heard that somewhere, and I have a bunch of crows I’d like to get rid of.

— Elizabeth, Cupertino

DEAR ELIZABETH: Amazingly, it is true, if you do it right. You don’t want the crows to see you putting out the fake crow, so do it at night. Once the crows see it in the morning, they may gather around it — to mourn, perhaps — before taking off for new digs.

Contact Joan Morris at AskJoanMorris@gmail.com.