Author: David B. Williams

The Wasp and The Spider

Warning, this is not geology related (though it does mention a cairn) but I think it’s pretty cool natural history nonetheless. Yesterday, I spent 40 minutes watching a nifty little episode involving a wasp and a spider. It started when I noticed a caterpillar on a concrete block retaining wall in our backyard. When I got closer to the wall, my eyes were drawn to a metallic blue flash six inches below the caterpillar. The flash came from the wings of a black, half-inch long wasp, which had a firm hold on a brown spider with a body about the size of a lentil.

The wasp was pulling the spider up the wall. After topping the wall the wasp and the spider dropped into the soil and duff inches behind the blocks. The wasp began to tug the spider over twigs, needles, and small rocks for about four inches, when it let go and started crawling around with short flights. Twenty seconds or so later it found what it was looking for, an entrance to what looked like an underground chamber, into which the wasp disappeared.

After the wasp emerged it flew directly to the spider. It landed, grabbed the arachnid’s abdomen, and began to pull it toward the hole. Not deviating from its route, the spider climbed over fir cones and through low vegetation, eventually letting go of the spider three inches from the opening. It then headed to the hole and began to excavate like a dog, using its legs to shuffle soil out of the way. Next it entered the hole, where I could not see what it was doing, though periodically it would back out, toting a small stone, some as much as a third as long as the wasp.

[nggallery id=25]The wasp continued excavating from within and from the entrance, occasionally going back over to the spider, where it looked like it was assessing the larger bug’s size. After about 30 minutes, the entry and underground chamber must have been large enough as the wasp returned to the spider and maneuvered it to the edge of the entry. It then grabbed the spider’s rump and pulled it into the chamber. It’s final step was the one that delighted me the most—it built a small cairn of four little rocks to mark the entry.

I am pretty sure that I had been watching a Pompilid wasp. This group of often large and colorful wasps is known for its macabre egg-laying lifestyle, Pompilid wasps, also known as spider wasps and tarantula hawks, fly around till they find a spider, sting and paralyze it, then drag it to an underground chamber where they lay an egg in the still-living spider. When the egg hatches it has a ready-to-eat meal. Pretty cool.

Okay, I admit that I piled up the wee rocks to make the cairn, sort of a low level publicity stunt for my new book, but I like to think that the wasp would have made a cairn if it could.

 

 

Building a Mile High Cairn

Apparently size does matter. Consider the use of cairns to make mountains bigger, or at least taller. More often those who hatch such schemes do so to make their mountain taller than someone else’s mountain but cairn builders have also done so to raise their peak to a mythical height. Over my next couple of blog posts I will discuss the whys and wheres of such cairn erection. I will begin with the lowest elevation peak but also one of the most famous cairn destination spots for hikers: Katahdin in Maine.

Surveyor Charles Turner Jr. and six men are the first people known to have climbed Catardin, as Turner labeled it. When the team reached the summit on August 13, 1804, they did not build a cairn. Instead, they cut their initials into a sheet of lead and left it and a bottle of rum on the summit. Sporadic visitors attempted to climb Katahdin over the next several decades. These include Maine’s first state geologist (1837), Charles Thomas Jackson and Henry David Thoreau (1846). Thoreau described Ktaadn as a “cloud-factory,” whereas Jackson wrote:

“From the observations made upon Mount Ktaadn, it is proved, that the current did rush over the summit of that lofty mountain, and consequently, the diluvial waters rose to the height of more than 5000 feet. Hence we are enabled to prove, that the ancient ocean, which rushed over the surface of the State, was at least a mile in depth…”

Not until 1847 was their a report of a cairn. In that year, Maine’s state botanist, Aaron Young, Jr. led a group to the top. Naturalist George Thurber wrote “the declining day warned us to hasten our departure, and each one adding a stone to the rough monument there, we all joined in singing Old Hundred.” He made no note of Noah’s Flood.

By 1853, there was “a considerable rock cairn supporting a bottle containing birch bark pieces inscribed with the names and dates of other climbers,” notes John Neff in Katahdin: An Historic Journey – Legends, Exploration, and Preservation of Maine’s Highest Peak. Photographs from the turn of the century show that the one cairn had multiplied to two, each about five feet high. No one knows why there were two or when the second one disappeared but just one cairn has been on the summit since the 1930s.

Curiously, surveyor Turner estimated the peak to be 13,000-feet-tall, more than double most later estimates, which bounced between 5,150 to 5,623 feet. Then in 1927, another surveyor, Floyd Neary, determined that Katahdin’s elevation was 5,267 feet. Neary’s number, so close to a mile, apparently excited some folks, who decided that Katahdin should attain that mythical height. They did so by erecting a thirteen-foot-tall cairn on the summit.

No one knows when these stones were piled up but a tall cairn is on the summit. Because of this precisely built cairn, you will find that people, guide books, and web sites often refer to “mile-high Katahdin.” This cairn is even more famous and more of a destination because it is the northern end point of the Appalachian Trail.

Whether the summit cairn is exactly thirteen feet tall is subject to some debate. There is no official measurement of it. John Neff wrote me that “In regard to the 13-foot-cairn, I agree that the idea might have been achieved back when the elevation was settled, but I have never had the impression that was something that was kept up for too many years.” Even if it is an apocryphal story, I suspect it’s too appealing to be debunked.

Next, I will write about cairns in Colorado.