[midvalleybirds] Perhaps no Cassins Finch on Marys Peak

clearwater at peak.org clearwater at peak.org
Mon Jul 8 20:06:12 PDT 2019

Thank you, Howard ... and I really mean a huge thank-you. 

There is a certain school of thought among Oregon birders, that goes back quite a few years if not decades, that "you can believe what you hear." 

For the past 10 years or so I've spend a lot of field time during breeding season, doing point counts (where you really need to assume that you can believe what you hear, since the methodology is built around it) but also territory-mapping and other types of surveys that give you more time to follow up on birds that you think you heard. 

When you spend time tracking down every single bird that you hear, there are often surprises. I don't want to dismiss all heard-only reports of out-of-range or out-of-season birds, because some of them might be correct. But many of them probably aren't. Some birds just don't sing the "right" song for their species, and others are skilled mimics. 

Point-count methodologies and birding-by-ear work best when applied to species that are known to be reasonably common in the survey region, so a certain rate of errors in identification by ear won't make a big difference in the the results. We rely on that all the time when we do point-count-based surveys like the Breeding Bird Survey. No doubt we make some mistakes but they'll wash out in the results, so long as our rate of mistakes isn't too high. 


On Tue, 2019-07-09 at 02:43 +0000, howard bruner wrote: 
Did I say a number of Cassin's finch? What I should have said was maybe one or two now that I have studied my recordings. I would have to lay eyes on the bird to confirm because I have found extreme variation in the LABU songs, with a pretty darn good rendition of CAFI that just doesn't end quite right. 
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