[obol] Wrentit expansion, blackberry table-pounding

[David Fix Jude Power]

Interesting thread on Wrentits.  I happened to live within a few miles of the extreme e. edge of the bird's range in n.e. Douglas County, at Toketee Ranger Station, in the mid and late '80s.  At the time, there was seemngly only a small population on a clearcut flat shortly above Hwy. 138 s. of Toketee called Fish Creek Desert.  The clearcuts there had grown in with mountain whitethorn, a hip- to shoulder-high ceanothus.  Clearcuts elsewhere on the district--even a few miles from Fish Creek Desert--did not offer this ceanothus (they weren't flat, they were on slopes favoring other "Cascade chaparral" species) and I encountered only one Wrentit in such a site, which I thought was interesting.  That was twenty years ago, and things might have changed as the average age of clearcuts has increased though a reduction in logging on the Stumpqua.      

I've seen Wrentits in blackberry too many times to remember.  I think I may have been the first person to experience Wrentit at Skinners Butte in Eugene, about 1979.  The bird happened to have been in Himalayan blackberry.  They were also in blackberry at Shore Acres Park, although a lot of snowberry was also available under the oaks.

When I planted trees with the Hoedads in the winter of 1981-82 there were Wrentits in some numbers in all of the sites we worked at in the low mountains out of Lorane.  They were in salal at the edge of the regrowth stands, as well as out in the hemlock-heavy seral stuff in the clearcuts.
 
I agree with what Mike Patterson says about blackberry having helped out--but not by itself having effected--a gradual advance at the n.e. corner of the bird's range.  The expansion of Wrentit coincided with wholesale conversion of forests to setback (and then maintenance of that setback through rotation), which would for sure be the first theory to look at, since it was such a widespread, interconnective, and unifying phenomenon in the lower mountains of western Oregon.  It seems we are all on the same page here.

I would like to shift gears here and say a few things about Himalayan blackberry.  I think the degree to which it has been beneficial for birds across the landscape is perceived and appreciated by disappointingly few birders.  Here's why I appreciate it.  Please check out your own impressions over your career as naturalists on the landscape in Oregon and compare.  Note, the snags in your sweaters may vary.  

--If it replaces indigenous blackberry, it seems typically to be replacing it with a shrub that offers considerably more mass as well as structural development and larger, more abundant, and more autumn-persistent fruits.

--It occupies and heals abandoned farmland, pastureland, and industrial and other disturbed footprint.

--It can't displace true wetland plant communities, but rather it often effectively marries marshes with uplands, and in a well-woven manner no other plant that comes to my mind can do.   

--Look down your block.  It protects a great many tiny urban and suburban streamcourses (in Eureka we call them "shopping cart gulches") with established side and overhead cover.  Small openings in it serve as a deer-resistant nurse bed for grand firs, cedars, and deciduous trees, and the protection it provides generally requires no management.  

--With ivy becoming an increasingly prevalent exotic pest within ten miles of any human assemblage because of yard-trimming tips off side roads, it is worth noting that exposed sun-blackberry mounds and ivy appear not to mix.  Roads and reptiles, blackberry and ivy.  Thus big open blackberry patches act as a buffer and as a bar to spread.
      
--It offers food and shelter to tens of thousands or, who knows, across its range, maybe hundreds of thousands of small birds.

--It serves as forage, denning, and travel corridor habitat for herps and prey base rodents, shrews, and the like, and the Western Screech-Owls and all manner of Four-legged Charismatic Mesovarmints that eat them.

--Blackberry mounds collect and preserve for a long time within them the naturally abscised coarse woody debris that falls from alders, cottonwoods, Douglas-firs, or whatever other overarching trees there may be, building up a base of structural and protective material that decomposes at variable rates.  Much of this can be deposited, and distributed well into sun-exposed patches, during windstorms.  I have noted that this material becomes valuable to amphibians (including Red-legged Frogs), beetles, and other invertebrates.   

I find that, all else being equal, suburban and rural settings with rambling Himalayan blackberry here and there offer the best land-birding.  Part of this attraction likely springs from the fact of the blackberry, while some may have to do with the typically broken, partially connective and often uneven-aged plants in association with it (alders, wetland veg, yards, etc.).

It has occurred to me that the rate of increase of this plant has probably slowed to a creep compared to what it once was, since it is established somewhere close by nearly everywhere it seems it can grow.  The battle is over, and the plant won.  I count myself not dedicated to eradicating it for eradication's sake.  
     
I might also add that I have had a lifelong love affair with native vegetation and plant communities of the Pacific Northwest, and Jude and I are members of the California Native Plant Society.


David Fix
Arcata, California
40 51 N
124 04 W
Baja Jefferson   

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