The event described below was all to common to us residents of Leavenworth
and surrounding areas a few years back. Hundreds of siskins, finches, and
possibly crossbills were clobbered all winter long, mostly along the
section of Stevens Pass from Mill Valley nordic center to Yodelin. We
sent our reports to WSDOT who did some analysis - and biologists from
USFS, USFWS, & WDFW all chimed in. The conclusion we came to was that
these seed-eating birds needed grit to process the seeds in their crop,
and the snow that year was amazingly deep. Without a "natural" source of
grit they turned to the roads. The problem was the salty material that
was sprayed on the roads to reduce the icing for safe travel. The salt
was injested along with the grit, causing a sort of "salt poisoning". The
birds OD'd on salt and were mentally/physiologically incapacitated to the
point that they were not able to avoid being killed by cars. Entire
flocks were sometimes killed with new flocks seen foraging for grit among
the dead. Tragic and heartbreaking.

Janet Millard
Leavenworth, WA
(USFS wildlife bio tech)

> So perhaps you can help me understand a scene of terrible carnage
> in Stevens Pass a couple winters ago. We were driving over to the
> east side to cross country ski when the snow scraped on the
> roadside was higher than the truck and the roads were snow-
> covered. There were seemingly hundreds of small birds on the
> roadway (too much traffic to try to identify or photograph), getting
> absolutely mowed over by cars. I couldn't figure for the life of me
> why they kept flying down onto the roadway and it was really awful
> to see so many killed. Is this the cold/paralyzed affect? And why
> would they keep landing on the road?