Date: 1/7/19 6:11 pm From: <clearwater...> Subject: [obol] Re: Common birds: Bewick's Wrens and Golden-crowned sparrows
Lars Norgren wrote:
> The proximity of Luckiamute Landing to annual flood plain means it is affected > by the moods of the Willamette. High water displaces ground feeding birds. I'm > not sure the Willamette has risen to anything near its usual winter level yet."
Lars & All,
The main concentration of Bewick's Wrens was in the back part of the Vanderpool tract portion of Luckiamute State Natural Area, not the Luckiamute Landing tract. It's a mix of oak woodland/forest, Oregon-ash swales and fields so very different from the Luckiamute Landing tract. Most of it was mapped as Roemer's fescue type (upland) prairie or oak savanna in the 1850s, with sort of a tiger-stripe pattern of "hardwood forest" for the ash swales (old oxbows) separated by oaks on the higher gravels. You can see this well on the LIDAR images.
That area, though it runs right up to the Willamette, mostly isn't inundated by floods in most years, but it does become hard to access during high water since the swale crossings can have water over your head. I've sometimes thought about bringing an inner tube along for this CBC, since there's a lot of habitat back in there.
Right now the Willamette and Luckiamute Rivers are running at levels that are fairly typical for most winter months, though far below flood stage. This means that the benches right along the river are still above water but they're narrow enough (~50 ft wide) that you can bird them from the high bank fairly effectively.
A few of the Bewick's Wrens that I detected were down on those benches but most were up in the somewhat misplaced "riparian" shrub plantings (again, most of this area really should have been restored as oak savanna or upland prairie, according to the 1850s survey data), which are structurally more like brushland.
That area down on the benches is not really Golden-crowned Sparrow habitat, so I doubt that the somewhat low river levels were important for detecting them. If they were around, they should have been doing their usual "tidal feeding" thing, hanging out in the brushy/wooded edges and coming out to feed in the open field areas. I walked 2.5 miles of edge and open brushland in that 30-acre patch and did see plenty of juncos, just no Zonotrichia sparrows other than White-throated Sparrows.
The Luckiamute Landing tract did have some White-crowned Sparrows along the road. I may have missed some brushy field-edge habitat around the main field because a guy was out hunting that edge (not sure what he was after, he didn't have a dog, but anyway I didn't want to mess up his hunt). But I walked that whole edge on Friday and didn't find any Golden-crowns, just a Coyote looking for voles.