Date: 11/19/25 6:31 am From: Matt Bartels via Tweeters <tweeters...> Subject: Re: [Tweeters] WA County Year List Project updated through October 2025 [WA Birder]
Hi Dennis -
Interesting potential future projects for someone with some time and a bit of stats literacy.
On eBird, you can get a lot of interesting info w/o digging much.
If you go to the ‘Explore page’ for any county, right up top you’ll see the total # of species reported, # of checklists, and # of eBirders. A bit further down, the same figures for the current month are presented.
With just some time, you could pull all those markers for all the WA counties.
I assume there’s some point after which the # of birders is enough to reach ’saturation’ where more birders doesn’t continue to lead to more birds. At that point, I’d expect habitat to be a bigger factor in the # of birds found. these two factors are of not independent -
There’s huge variation in how heavily birded counties are - just a couple examples:
King County this month so far has reported 163 species on 2783 lists from 879 eBirders
Garfield Ccounty, by contrast, has reported 75 species on 37 lists from 9 eBirders
When King has 100x as many checklists and eBirders in a month as Garfield, it isn’t surprising more species have been found in King this month….
You could definitely build out that info - I’m sure there are worthwhile factors that would muddy the findings - Rather than hypothesize all the reasons this or that presentation of the data is flawed, I favor trying to use a bunch of different lenses to look at the data we have, knowing none will be ‘perfect’…
Interesting to noodle around on all this
Matt Bartels
Seattle, WA
> On Nov 18, 2025, at 7:03 AM, Dennis Paulson <dennispaulson...> wrote:
>
> Matt, thanks as always for your thorough analyses.
>
> I wonder if a significant part of the analysis is missing, though—the number of birders who report those bird species.
>
> I don’t know any other way to do it relatively simply than to get a figure for the number of people who sent in eBird lists each year (for each county, even better) in recent decades. How about graphing that vs. number of species?
>
> Can we look at it thinking that as the number of birders go up, we should be seeing more species? Apparently not, but then what does that mean?
>
> It would also be interesting to analyze the species themselves. Which species have been reported in every single year for which you have been keeping records? Which species are missing in just a couple of those years, and any ideas why? How about volunteers to take on some of these analyses on winter days too rainy to go out birding?
>
> Dennis Paulson
> Seattle
>
>> On Nov 18, 2025, at 6:00 AM, Matt Bartels via Tweeters <tweeters...> <mailto:<tweeters...>> wrote:
>>
>> Hi Tweeters & InlandNW Birder
>>
>> An updated version of the 2025 County Yearlist Project is up and available at Washington Birder.
>> http://wabirder.com/county_yearlist.html >>
>> Thanks compilers for all your work, and thanks everyone who has contributed.
>>
>> This update, coming at the end of October and as Fall Migration has pretty much wrapped up, is a relatively stable point to check in - only a few late migrants and then winter birds left for the year lists.
>>
>> Here’s how things look compared with recent years:
>>
>> We’ve tallied 390 species statewide as of the end of October in 2025. That’s one higher (essentially the same) as we had at this point last year and the year before.
>>
>> For Western WA, our 361 total is 1 lower than last year, and 4 lower than 2023.
>>
>> For Eastern WA, our 319 total is 4 lower than last year, and 5 lower than 2023.
>>
>> Overall, we’re looking pretty similar to last year.
>>
>> Looking at the percentage of each county’s total list seen, 33 counties have seen between 60% and 75% of their county’s total list - a pretty consistent result saying about 2/3 of the birds on any county’s have been found The biggest outlier: Okanogan County, which has seen 81.6% of its list total already this year.
>>
>>
>> 34 counties have totals within 10 of their 2024 totals.
>> 18 counties have higher totals than this time last year, while 17 have lower totals than at this point last year.
>> Four counties have exactly the same total as at this point last year [Asotin, Pierce, San Juan and Walla Walla].
>>
>> 91 species have been seen in all 39 counties, and 168 species have been found in 30 or more counties.
>>
>> If you'd like to take a look at where things stand, the list and many other interesting files are at the Washington Birder website:
>>
>> http://www.wabirder.com/ <https://urldefense.com/v3/__http://www.wabirder.com/__;!!JYXjzlvb!zG34Bg6bHN7DFbBBUaTDwShMg1FqqyJYn5MFZzMWbfTt3uAOqMTkSTJu0EzT-2kdesFyODa5qw$> >>
>>
>> A direct link to the 2025 county yearlist & the list of county compilers contact info:
>> http://www.wabirder.com/county_yearlist.html <https://urldefense.com/v3/__http://www.wabirder.com/county_yearlist.html__;!!JYXjzlvb!zG34Bg6bHN7DFbBBUaTDwShMg1FqqyJYn5MFZzMWbfTt3uAOqMTkSTJu0EzT-2kdesFgZPFJVA$> >>
>>
>> Thanks to all the compilers and all those pitching in to sketch a picture of another year's birds in WA.
>>
>> Good birding,
>>
>> Matt Bartels
>> [mattxyz at earthlink dot net]
>> Seattle, Wa
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