That summer we kept hearing hummingbirds at Steens Mountain, first on the west side near Fish Lake, and then higher up near Whorehouse Meadows. We'd see the flash of color and the furious movement, but could never get close enough to identify which of the several species known to live on Steens it might be.
What a shock we got at Wildhorse Lake when we finally got close enough!.. Maybe it was the 8,400 ft. altitude which finally slowed them down enough to see and photograph, or the cold. Unbelievably, these bright, blazingly fast monsters, big as hummingbirds, are some strange type of.... MOTH.
and again 2/07/2004: Finally, we have been offered the definitive
identification of these moths by Chuck Dethloff: it is a White-Lined
Sphinx moth (Hyles lineata), and Chuck notes that this moth is
sometimes also known as the Striped Morning Sphinx (Celerio lineata)
in some older moth books.
"We have several varieties of sphinx moths, otherwise known as hawk moths, in Oregon. They are extremely robust moths and amongst the fastest flyers amongst all Lepidoptera. Some of them, such as this example fly during the day, most commonly early or late in the day, though I have observed them during mid day on occasion back in Minnesota.
The wingspan of this species can reach 3.5" from tip to tip of the fore wings. Given their robust bodies and jet speed type flights, it is not surprising that they resemble hummingbirds. Their are even larger species of daytime hawk moths, the Pink-Spotted Hawk moth has a wingspan approaching five inches. The largest one I know of in the US is the Big Poplar Sphinx with a wingspan of 5.5 inches!
The identification of the moth off of your web site is conclusive because the White-Lined Sphinx moth has two major features visible on your excellent photo, specifically the pale tan stripe on the fore wing that extends from the base to the apex. Also the distinctive white streaks that cover the veins and the outer edges of the hind wings."
As to how the heck such big, active creatures manage to survive in such a cold, snowy, dry, extreme climate as Steens Mountain, here is part of Chuck's reply:
"...The adult moths themselves do not live through the winter. Some moth species overwinter in the egg stage; however this particular species spends the winter underground in it's pupal stage where it transforms itself from a caterpillar into an adult moth. In the late summer or early fall the caterpillars finds or digs themselves into shallow burrows underground and remain relatively dormant until the spring warmth returns.
After completing this metamorphosis in the early summer the pupae actually twist and wiggle themselves back up to the surface of the ground so that the adult moths can emerge from the pupae to lay eggs and start yet another cycle. In eastern Oregon there would likely be only one brood per year because of the short growing season, in more southerly locations of the US this moth can have two broods one of which overwinters.
I suspect that the moths you saw probably spent their entire life cycle somewhere on Steens Mountain. The varied vegetations found during the growing season would provide several choices of food for both the larvae as well as the adults. Winter snows provide adequate protection for the buried pupae, which is how they manage to overwinter in even colder climates such as those found in the upper plains and/or upper midwest."
As to a more specific answer abut what these hungry moths find to eat in such a treeless alpine desert environment, here is the answer: "...The adult sphinx moths feed on the nectar of a wide range of wildflowers including thistles, primroses, clovers, etc., so they would have a good variety to choose from during summer even in the relatively barren areas around Wildhorse Lake. Since they are very strong flyers they probably traveled many miles (locally) during their adult lifetimes feeding, mating, and laying eggs."
Kiger Mustangs are another quite unusual form of wildlife found on Steens Mountain... They are wild horses probably descended directly from runaway Spanish horses from hundreds of years ago, maybe as long ago as Francisco Vasquez de Coronado's famed trip into Kansas in 1540 in search of gold in the fabled Seven Cities of Cibola/Quivira. Additional information about their lineage includes that Kiger Mustangs are very akin to the fabulous calvary horses of the Roman Empire, part of the strength of the Romans that gave them the muscle to take over a truly vast area. The Kiger Mustangs roam the lower portion of the Steens' most well-known geologic feature, the deeply-craved glacial U-gorge named Kiger Gorge. This winter view was taken from near its head at about 8600 ft.
* Photo courtesy of Jim Whinston, Portland, Oregon