Everyone, at some time, has experienced an unexpected “zap” of static electricity. In our house, these “cat nap zaps” usually occur on Saturday afternoons and involve cozy woolen afghans and furry cats. But who knew that zapping was already going on all around us, especially in our flower gardens?
Two weeks ago, we reported on a recent study from the University of Bristol, where scientists found that “bumblebees are able to find and distinguish electric signals given out by flowers.” And we discussed how this electrical signal is created when positively-charged bumblebees approaches negatively charged flowers. (As you may recall from your high school physics: an object carries a negative charge when is has a surplus of electrons and it carries a positive charge when it has a deficiency of electrons.)
This week, we’ll talk about the message this electrical signal conveys to bumblebees. When a positively-charged bumblebee lands on a negatively-charged flower blossom, the flower blossom’s charge becomes slightly more positive as it releases some of its electrons to the bee.
How much more positive? According to this NatGeo article, “the electrical potential in the stem of a petunia goes up by around 25 millivolts when a bee lands upon it. This change starts just before the bee lands.”
How long does the change last? For “just under two minutes, which is longer than the bee typically spends on its visit.”
How do bumblebees sense the flower’s electrical charge? Scientists don’t yet know but they “speculate that hairy bumblebees bristle up under the electrostatic force.” We know that bumblebees are covered with fuzzy hair and that these hairs are very sensitive, with “receptor cells located at the base of the variously shaped hairs.” Imagine Gene Wilder’s hair in “Young Frankenstein” and you’ll know what I mean.
So what is the message for the next visiting bee? The change in the electrical charge is “like a sign that says ‘Closed for business. Be right back.’” It takes time for a flower to replenish the nectar that was consumed by the first bee. So when another bee approaches the same blossom, it senses the change in electrical charge and does not waste time visiting that flower.
So let me end this report with a piece of advice: the next time you’re awakend by a “cat nap zap”, check their food dish. It may be empty.
Upcoming Outdoor Events:
Trail Maintenance Schedule. Come join our volunteers as they help maintain our trails. Contact Steve at firstname.lastname@example.org for time and place.
Wednesday mornings, April 3, 10, 17, & 24.
Saturday mornings, April 6 & 20.
New trail maps available. If you’d like to explore a bit on your own, the City of Santa Clarita has a website with trail maps of our local open spaces.
There’s also a new website for bicycle riders.
You can listen to stories like this every Friday morning at 7:10 a.m. on “The SCV Outdoor Report”, brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.
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