Bird Brain – It’s a Good Thing!
Black widow spiders are known for the inescapable red hour glass marking on their underside. This marking is like a beacon to all creatures that screams: “Poison – stay away!” And it works, to all except those who are the spiders preferred meal, ants, cockroaches, caterpillars, beetles, grasshoppers, even scorpions.
So, a study was done at Duke University as to why this warning sign works on birds but not insects.
The researchers printed 3-D likenesses of two spiders, one with a red hour glass and one without and posted these on bird feeders. Oddly enough, the birds were 3 times more likely to peck at the spider likeness that was just shiny black, without the hour glass as they were the ones who were obviously made to look like black widow spiders. And strangely enough, some were even seen to sort of jump back when they discovered the red hour glass.
This behavior is good not only for the health of the birds, but also keeps the spider from being a tasty tidbit to a hungry bird. But the insects had no such hesitation upon seeing the red hour glass and more often than not, they would be caught up in the spider’s web and voila!, lunch is served.
Apparently the birds eyes are equipped with photoreceptors that can pick up the red hour glass and send a warning message to their brain. Insects have no such mechanism. Which is the way nature intended. If insects were warned off the black widows web, the spiders would go hungry. And if there were no hour glass on the spider the birds would eat them all, helping to dwindle their population.
Black widow spiders are the most poisonous spider in North America and can put a human in the hospital with their venom. But they do not seek out humans. Usually a person gets bitten because they invade the spiders personal space and the spider feels threatened.
Nature takes care of itself, without the help or intervention of humans. Sometimes we need to remember that all creatures have a purpose, even black widow spiders.