Archive for category Nature
Slugging down beer—which brew preferred by shell-less terrestrial gastropods
Inspired by my new web-based “Launch Pad” to the book DOE Simplified, PhD biologist Gaston Habets put his new statistical know-how to good use in his own backyard out in California by offering a choice of beer to the slugs eating up his garden.
Being a native of a cold clime I’d no idea how troublesome slugs could be until some years ago when my cousin in the Bay Area had me out to her place for dinner and asked me to help her gather up greens from the garden. The size of the slugs surprised me: The Pacific banana slug approaches a foot in length according to this New York Times science blog.
Given their gentle nature and top speed of 0.0055 miles per hour, one need not fear these slimy creatures. The only thing is that they eat up the gardens. So that sets the stage for the humane solution of sidetracking slugs with a bowl of beer. But which brew do they prefer? Gaston did his bit for the sake of garden science by setting out eight trays at specific locations around the vegetables and randomly pouring either Bud light or alcohol-free O’Doul’s. He repeated this experiment over four nights in a way that blocked out any differences in the nocturnal feedings.* The graphic shown here shows the outcome: By nearly a 3-to-1 ration slugs preferred Bud Light over the O’Doul’s. They did not get thrown off by the random location of the beer—the slugs found their favorite bars and bellied up.
*Gaston’s data showed a maximum slug count on Saturday night, but then they dropped off to a minimum on Sunday. My conclusion is that slugs party hearty. Who knew?
Slugs prefer Bud Light over O’Doul’s
P.S. It seems that slugs from coast to coast really do prefer Bud from what I see here.
Strange times: Ice forming in unlikely places and melting where it shouldn’t
Posted by mark in Nature, Uncategorized on December 9, 2012
My flight yesterday from Minneapolis to Santiago got held up for de-icing. Being so near to the year-end solstice, the change in seasons from Minnesota to Chile could not be more dramatic—a swing of 45 degrees in solar angle relative to the ecliptic plan. So it’s out of snow (storming today back home) and into 80+ degrees and pure sun. : )
Things are wackier than I’d thought in regard to where one might expect to find ice nowadays. For example, who would have thought that water could freeze on Mercury? But that’s what NASA recently reported based on a shout out from their spacecraft Messenger, which detected polar hydrogen via neutron spectroscopy. See the details here. I enjoyed the quip by Sean C. Solomon, the principal investigator for Messenger, about there being enough ice to encase Washington, D.C., in a frozen block two and a half miles deep.* That might be what’s needed to cool down all the rhetoric about the fiscal cliff. 😉
Meanwhile the worries about the warming climate melting Earth’s icecaps just keep coming on. Concerned about contrails contributing to the greenhouse effect, the Washington Post is now demanding the Santa’s sleigh be grounded. Read this 12/4/12 blog and weep. : (
*On Closest Planet to the Sun, NASA Finds Lots of Ice, 11/29/12
Good bees and bad bees
People in my home state believe in a high degree of politeness which we deem Minnesota Nice. Thus it should be no surprise that entomologist Marla Spivak, who runs the Bee Lab at the University, has developed a trait for bees that she calls Minnesota Hygienic. These bees have been bred to detect and remove damaging diseases and parasites from the hive, thus lessening the likelihood of colony collapses that have confounded keepers nationwide. Spivak’s work came to my attention in this recent Washington Post article featuring beekeepers in nearby Maryland who get $165 for queens whose offspring do not tolerate parasitic mites and, hopefully, this zombie fly.
This concern over keeping bees healthy is not shared by everyone. For example, see this horrifying report from Florida (where I happen to be at the moment). If you fear bees (apiphobia), do not watch the video.
Why you should be very leery of forecasts
Check out this blog by statistician William Briggs that gives the heads up on how Hurricane Predictors Admit They Can’t Predict Hurricanes. Years ago as a chemical engineer working on process development I would be encouraged by plant personnel to crank old data through a regression analysis to model the operation, thus avoiding any work on their part to run designed experiments. The joke was that we got very good at predicting what would happen last month.
In this case the issue is hurricanes. As Briggs explains, the top experts can fit past data very well (r = 0.79 for 50-year period the last half of 20th century). He refers to this as a ‘hindcast’. But, as the hurricane forecasters themselves admit, these models predict so poorly (r = 0.04) that you may as well just use an average — what I call the ‘mean’ model as a double meaning (ha ha) because it is so disappointing for the analyst.
What it boils down to is that any forecasts on hurricanes this early before the coming season will really just be a lot of hot air, despite impressive statistics from models fit to prior years. The same goes for long-term outlooks on other natural phenomena.
Mind-reading fish know I am out to catch them
Last week I enjoyed a relaxing sojourn up in the north woods of Wisconsin. The resort encompasses its own pristine pine-ringed lake featuring a 26-foot fishing hole. Just before I headed off for my vacation I read this Scientific American report on The Mind-Reading Salmon: The True Meaning of Statistical Significance
. Although I think they meant to be disrespectful of p-values in this case, my feeling, based on empirical evidence from a large sample size – hundreds of unsuccessful casts of my lure around the shore and over the hole, is that some fish living in isolated areas have developed mental telepathy. How else do they avoid being caught?
PS. Here’s a picture of me in happier days at a different lake last summer. My brother-in-law insisted that the first one to catch a crappie would have to kiss it. Evidently this fish thought it might be fun to try, knowing I’d then release it back into the lake.
The chaotic, yet regular sounds of weeping waters and lapping waves inside Lake Superior sea caves
Earlier this month I enjoyed a wonderful sail out of Cornucopia, Wisconsin to Lake Superior’s Mawikwe Sea Caves — described nicely here in a pictorial blog by the Howder family.
Mawikwe means “weeping woman” in Ojibwe. Due to heavy rains in the days leading up to our voyage, the caves were weeping steadily, as you can see and hear in my video. I was fascinated by the cacophony of dripping water combined with the galumphing of the waves into the baby caves at water level. It provided a pleasing mix of randomness and rhythm. Turn up your volume and listen for yourself.
PS. By the way, I learned that by yelling into a sea cave you can (pun intended!) duet yourself.
How hot? 103 under our shade tree!
According to my morning newspaper (St. Paul Pioneer Press), yesterday’s record temperature made it hotter hereabouts than a billy goat in a pepper patch, or the devil’s underwear (I hope he is not a tweeter like that New York Congressman), or two bears fighting in a forest fire (down in Arizona, I suppose). Even so, a vestige of the once 60-foot high pile of snow dump in downtown St. Paul remained intact. Perhaps it will disappear today. I hope so, because it will be back in the 60’s by Friday – colder than a basement toilet seat as Minnesotans like to say.
Winter not loosening its icy grip on Spring
I woke up to snow yesterday morning. It couldn’t quite cover the greening grass underneath, nor did it seem to discourage the budding bushes. Today the snow has disappeared and the near 40 degree F temperature seems mild with the power of April’s sun and the abatement of fierce northern winds. However, our Canadian neighbors are not faring quite as well, as evidenced by this very cool (literally and figuratively) photo from my sister – a resident of Calgary. Notice how the snow fingers feature icy nails — chilling!
When will Winter finally loosen up and let Spring spring free, eh? Maybe May…
First signs of Spring – premature return home by robins
As you can see from this photo taken Friday while cross-country skiing, Spring has not sprung in my neck of the woods. However, just overhead as I took this shot were several dozen robins perched in the birch. They were chattering a great deal – I imagine in complaint about which bird brain thought it was time to migrate back north.
A couple of years ago at this seasonal juncture I wrote about phenology – the study of timing for nature’s ways. For us in Minnesota the robins’ arrival is a sure sign of warmer weather around the corner.
Having just returned from a Spring break in Florida, I wondered how these southerners can detect seasonal changes. My searching on internet reveals little, other than this announcement of the first phenology workshop in Florida in 2009. The one sure sign of Spring for Floridians is the hordes of Minnesotans coming down for a break. They probably trump anything more subtle from Mother Nature.