Steve, Andy, et al, I think you guys are both right. I haven't been in that area in several years, but it (Jarre Canyon and the whole Hayman Fire area) over the last 20+ years has had lots of budworm, Douglas-fir Tussock Moth, Douglas-fir Beetle, Douglas-fir Pole Beetle and other bark beetles (called "engravers") in the genus Scolytus. Usually what happens is one or both of the defoliators (the moths) chew the trees' needles for a few years, the affected trees become weakened (as indicated by top-kill), and one or more of the beetles finish them off. Usually the Douglas-fir Beetle (Douglas-fir equivalent of the Mountain Pine Beetle) hits the bigger diameter stems and the pole beetle and engravers are in the stems smaller than 10 inch in diameter. My bet would be a complex of insects is involved in the entire decline and death of the stand but the presence of the woodpeckers indicates bark beetles and/or wood boring beetles in the dead trees. If the needles on these trees that weren't moth-chewed (i.e., missing) are red, that would indicate the death is recent enough to indicate the woodpeckers are probably after bark beetles. If the tree crowns are pretty much needleless and gray, indicating the trees died two or more years ago, I would guess the woodpeckers are after the larvae of larger, secondary beetles like wood borers. I often refer to the borers that show up in the second wave of succession (riding the coat-tails of whatever it was that killed the tree) as "lawyers" - they are at the accident but didn't do it. If anybody goes back to this area, I'd be interested in what you think the woodpeckers are after (bark beetles would be right under the bark and their predation would be indicated by several shallow patches of pecking, extraction of borers would usually require deeper excavation of the outer rings of wood and be indicated by fairly widely-spaced gouges).
Dave Leatherman Fort Collins From: Steve Stachowiak & Melody Egge Sent: Sunday, April 03, 2011 9:57 PM To: [email protected] Subject: [cobirds] Re: Douglas County American Three-toed Woodpecker Cobirders, I thought that I would add that the "beetle kill" area as it was referred to by Andy is most likely attributable to Western Spruce Budworm. The large stand of dead defoliated trees is comprised of Douglas-fir while the Ponderosa Pines in the immediate vicinity remain in healthy condition. I visited this location on Saturday morning but had no luck with the American Three-toed so it is nice to know that they are indeed still in the area. There are also Williamson's Sapsuckers drumming in the stand across the road to the south. Good Birding, Steve Stachowiak Highlands Ranch, CO -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en. -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
