|8/8/2017 11:45:00 AM|
|The most wonderful thing about writing this column is the phone calls and emails. Last week, the phone was ringing off the hook (and vibrating in my pocket) with all you wonderful people calling to tell me about the outbreak of "monarch butterflies" that have taken over the foothills of the Cascades.|
But I'm sorry to say, those are California tortoiseshell butterflies, not monarchs.
California tortoiseshells winter over as adults, and somehow this is an advantage to their survival and helps them to build up their numbers. Then, when things are right (and I have no idea what "things" that may be) their numbers reach a point where the sheer numbers brings about an outbreak.
They have done it two times (as far as I know) since I rolled into Bend on my Harley back in 1951. Thirty years ago, an outbreak similar to this one took place in Northern California and was seen all the way to Bend. Unless research is carried out annually within the tortoiseshell populations, it's probably difficult to really put your finger on this or that cause. But no matter; it's astonishing when it takes place.
I believe this remarkable phenomena is tied to nature's way of ensuring survival of a species. Perhaps, when weather and food plants are in balance, close to 100 percent of a butterfly's larvae get what they need to develop the necessary chemicals to metamorphose into adults successfully. They mate and lay prodigious numbers of eggs; which in turn hatch - and because of the sheer numbers defoliate their food plants -which I have a hunch is even good for the plants in some way.
While this is going on, butterfly parasites also go into supercharge mode and somehow have the ability to lay eggs on the kajillions of caterpillars. During the similar event some 30 years ago, my wife, Sue, and I were living in Bend, having just returned from southeast Arizona where I was manager of the Ramsey Canyon Preserve.
During that outbreak of the mid-'080s, we were told tortoiseshell butterfly caterpillars in the Tumalo Creek watershed were defoliating all the ceanothus west of town. We were living in Bend at the time, and of course, Sue and I packed up our son, Reuben (Miriam and Caleb hadn't arrived yet) and went out to Tumalo Falls to take a look. It was astonishing to see that many butterflies filling the air, and to actually hear their wings as they flittered about, as well as larvae munching on ceanothus leaves.
When we returned a short time later we found uncountable numbers of chrysalids hanging on the bare branches of the ceanothus. We then discovered by accident that if we got close to them and stomped our feet they would all begin to shake and, I thought, clang like tiny bells. What a show!
We removed 20 chrysalids from the underside of the bare branches by using my pocketknife to cut the thin, silk pedicle attaching the chrysalis to the branch and took them home with us to photograph emerging butterflies. However, if my memory serves me correctly, of the 20 chrysalids, eight or nine developed as butterflies. Bright green parasitic wasps emerged from all the others.
During that outbreak I also recall the California highway department installing special truck washing equipment near Redding that was used to wash smashed butterflies out of the radiators to keep the trucks from overheating. And the UPS drivers were having a heck of a time, driving five miles then having to stop and clean the windshields of their trucks.
The OBOL website (Oregon Birders On Line) has been buzzing for weeks with birders sharing the tortoiseshell outbreak, and this one from Barbara and Dan Gleason of Eugene was particularly thoughtful as well as interesting:
"Seeing all the posts, I thought I'd add that these massive numbers of butterflies were also in the Clear Lake and McKenzie River areas too, this past Thursday.
"My granddaughter and I were up there for her first rowboat ride and everywhere we encountered massive numbers of tortoiseshells, to the point it made driving quite hazardous since one couldn't help but want to avoid killing them, but one could not drive as slowly as one need to accomplish this.
"We were glad to get off the highway and head to the lake where one could drive to allow them to pass by the car. They were largely not over the lake but were everywhere along the roadsides, especially near water...culverts, outhouses, included!
"Along the edge of the lake when one moved too quickly, they would all take flight and one could hear their wingbeats, too."
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