THE BUTTERFLIES OF DONNER SUMMIT

By Kathryn Gray

"The butterfly counts not months, but moments, and has time enough."  Rabindranath Tagore

Butterflies are probably the last thing to come to mind when one hears of Donner Summit.  One might think of the ill-fated Donner party, the dramatic granite landscape, copious snow, and skiing- but fragile butterflies?  Yet it turns out that Donner Summit and environs contain an abundance of butterflies.  Dr Art Shapiro, of UC Davis, has noted that, "Donner, for area, has one of the richest butterfly faunas documented in North America."

In an especially bountiful year, motorists may have an unpleasant encounter with armadas of Tortoiseshell butterflies on Highway 80 over the summit, doomed butterflies plastering their cars' windshields.  Lepidopterists wryly refer to those occurrences as a "radiator count", which of course provide no value for scientific purposes.

Fortunately, much better data is available on the presence of butterflies at Donner Summit.  Charles Fayette McGlashan, a Truckee resident and lepidopterist, and his "butterfly farmer" daughter Ximena spent time with collectors up at the summit at the end of the 19th century, and cataloged many species.  John and Tom Emmel published a well researched work on the butterfly fauna of Donner Summit in the 1960's, and now, Dr Art Shapiro spends considerable time studying the "Donner transect" in summers.  In his "Status of Butterflies-Sierra Nevada Ecosystem Project" paper, he noted seeing sixty-two species on the wing along four miles of Old Highway 40 (Donner Pass Road) in a single day.  All told, up to 115 different species have been observed at the summit.

As to Rabindranath Tagore's observation that, "the butterfly...  has time enough." I'm sorry to say that a butterfly's life up at Donner Summit is not an easy one.  Unpredictable snows can wreak havoc with the developmental process of a butterfly; successful species in the higher elevations have adapted by having only one generation a year (univoltine), and by undergoing diapause, a "sleep time" where no growth occurs.  However, individual species of butterflies are dependent upon select plants, and if anything occurs to cause the butterflies' development to be out of sync with their host plants, an entire species can collapse.

Van Norden Meadow, with it's extensive plant resources, and the surrounding granite slopes and balds that support montane chaparral, are rich feeding grounds for many species of butterflies, including Phyciodes orseis herlani, one of the rarest butterflies in Northern California.  Now, all these butterflies, who have adapted to harsh climatic conditions, are threatened by Royal Gorge LLC's plan to dam Van Norden Meadow, and their plan to blast two artificial lakes in the area around Summit Lodge.  In addition to completely wiping out butterfly feeding areas, Royal Gorge LLC's extensive planned development will cause habitat fragmentation, which decreases butterfly species' ability to rebound from climatic or other natural disasters.  If Royal Gorge is permitted to build their huge development, the summit's butterfly population may plummet.  Our butterflies will count neither months nor moments, but will have no time at all.  Our glides of butterflies, our ascensions of butterflies, our hovers of butterflies, will be but a fleeting memory.