Date: 3/12/18 6:41 am From: Joel Geier <joel.geier...> Subject: [obol] Re: Apparent extirpations of Least Bittern and Upland Sandpiper (was: OBRC Annual Meeting)
These remarks (below) from Dave irons were interesting though sad to see.
The birding community regularly celebrates additions of "new" birds to a state or county list, but there is no fanfare when a nesting species quietly drops off the list. This is natural, of course: The discovery of a "new" species for a given area happens as a singular event, but the disappearance of a nesting species may be recognized only after years of absence.
In the case of Upland Sandpiper, we can be certain with high confidence that the species is gone from its last known breeding sites in the Bear and Logan Valleys, due to the concerted efforts of the Grant County Bird Club to monitor those populations, year by year.
With secretive species like Least Bittern, it's more difficult to be so sure. There are vast areas of suitable habitat in Sycan Marsh where the species might still occur during breeding season, but which are mostly inaccessible to amateur birders. Presumably staff for USFWS, The Nature Conservancy etc. keep an eye/ear open for this species, but they're spread pretty thin. In 2008 the Klamath Bird Observatory (KBO) surveyed Sycan Marsh systematically for this species along with other "aquatic secretive marsh birds." KBO did find Yellow Rail but not Least Bittern in that year. But who knows if a single year's survey is adequate to establish their absence, considering that presence may depend on water levels, and the low probability of detection in a brief survey, even when they're present.
Local extirpations of breeding species such as Lewis's Woodpecker, Yellow-billed Cuckoo etc. can be overlooked when the species still occurs as migrants. In California, seemingly no one noticed that the state's last known nesting population of "Oregon" Vesper Sparrows apparently blinked out in the Crescent City area, sometime in the past 20 years. One might infer that from their absence on eBird checklists from anytime outside of migration, but it's hard to be know whether anyone searched actively for them in the right habitat.
No one posts an annual challenge for birders to predict which species will be the next one to drop off of a state or county list. But it's something to think about. What other species have already disappeared from "traditional" sites where birders used to count on twitching them for their year lists? We seem to lack a framework for keeping track of "notable absences."
Good birding, Joel
On Mon, 12 Mar 2018 David Irons wrote: ... At yesterday's annual meeting of the Oregon Bird Records Committee, we voted unanimously and almost so to put Least Bittern and Upland Sandpiper onto the committee's "review list."
Least Bittern, was initially on the review list when the committee was formed in 1978, but was then removed in 1984 in the wake of somewhat regular reports from the Upper Klamath Lake canoe trail, Malheur NWR and other marshes in southeastern Oregon. Over the ensuing 30+ years Least Bittern has rarely been reported in Oregon. There are only three post-1984 records in the eBird database. Perhaps this species persists as a rare summer resident/breeder in the state, but the paucity of recent reports suggests otherwise.
Upland Sandpiper has never been on the state review list, as it was an established low density breeder in several lush valleys in southern Grant County. During the 1970s, 80's and early 90's Upland Sandpipers could be reliably found during the nesting season in Bear and Logan Valleys and at a couple other sites between John Day and Burns. They were presumed to be breeding there and maintaining a modest self-sustaining population. Starting in the early 2000s they gradually became more and more difficult to find and there have been no reports from this area for at least a decade. Migrant Upland Sandpipers are still occasionally seen elsewhere in Oregon, but their rate of detection is now less frequent than a number of species that are on the review list (i.e. Hudsonian Godwit).