Tweeters,

The impressive movement of Clark's Nutcrackers occurring now in the Cascades
has generated several reports on Tweeters. I've put them together and now
make them available as one message.

Clearly, a region-wide irruption of this species is taking place, most
probably in response to poor seed production of their mainstay - whitebark
pine.

CLARK'S NUTCRACKERS MOVING SOUTH ALONG THE CASCADE CREST
17 September 2000

Dennis Paulson first posted to Tweeters the impressive movement of Clark's
Nutcrackers moving south this fall in the Cascades. I his posting of 10
September to Tweeters, he remarks on a trip to the Colockom area of Kittitas
County: "The featured bird was Clark's Nutcracker, however, which we could
hear at just about every stop. There were surely hundreds in the high
country, if not thousands, from the numbers we saw, constantly on the move,
presumably looking for food. Their primary foods are the seeds of whitebark
and ponderosa pines, and perhaps there was a failure of whitebark cone
production this year to bring so many of them to that area. But we never saw
any feeding in ponderosa pines, and there may not have been much of a cone
crop there, either. There were only a few type 2 Red Crossbills (ponderosa
pine preferers)."

Regarding observations a day or so later in the Okanogan, Dennis remarked:
"We found lots of Clark's Nutcrackers again in the Sinlahekin, chowing down
on ponderosa pine seeds (I've seen them there, at 1700' elevation, most
years)."

On the 17th September, a similar conspicuous southbound movement of Clark's
Nutcrackers was found along the crest of the Cascades of Yakima County.
Small groups were noted moving south right at the crest north of Chinook
Pass in the Sourdough Gap area. The Clark's Nutcracker is a pint-sized,
boldly patterned "crow", that specializes in harvesting and caching the
large seeds of the whitebark pine, a timberline tree found from the Coast
Mountains of British Columbia south through the Cascades of Washington and
Oregon to the Sierra Nevadas of California. One study found that a single
nutcracker cached more than 30,000 seed in one fall, for use later in the
winter. Most seeds are probably stored in crevices in wind-blown rocks (thus
mostly snow-free in the winter), making them available for use throughout
the winter. Further, this study found the nutcracker remembered the location
of many (but not all) caches. Caches not retrieved are apparently form an
important aid in propagating this species of pine.

My message to Tweeters brought the following response from Wayne Weber in
southern British Columbia.

Birders,

"The attached note from Richard Swanston of Delta is of interest because of
the impressive number of Clark's Nutcrackers reported on the move. The
movement of nutcrackers reported by Andy Stepniewski from Yakima County, WA,
obviously extends northward into BC. I also noted recently on OBOL (Oregon
Birders On Line) that a group of 5 nutcrackers was reported on Mary's Peak,
in the Oregon Coast Range west of Corvallis."

"Something funny is definitely happening with Nutcrackers in the Merritt,
B.C. area as well. Nutcracker numbers have been above normal all summer in
valley-bottom (ponderosa pine) areas. The number counted on my Canford BBS
route west of Merritt in July was 22 Nutcrackers, a 25-year high. In
addition, on September 17, I saw a group of 15 nutcrackers in a
valley-bottom location where they would not normally be seen, plus 3 more
flying across treeless rangeland near Douglas Lake."

"It would seem that Clark's Nutcrackers are experiencing a food shortage in
at least parts of their breeding range and are wandering to other parts of
their range-- and even to points outside their normal range-- in search of
food. This kind of mass movement or "irruption" of nutcrackers has happened
in a number of previous years in the Northwest. Anybody observing unusual
numbers of nutcrackers, or observing them in unusual localities, is
encouraged to report them so that we can put together a more complete
picture of what is happening."

Andy Stepniewski
Wapato WA
steppie at nwinfo.net