Scythebill 21.0: eBird 2026, AviList 2026, and new timeline views!

Scythebill 21.0 is now available, with a bunch of headline items:

• The eBird 2026 taxonomy is available
• We bid a fond farewell to the IOC taxonomy, and welcome the AviList 2026 taxonomy
• There's a new Timeline report in Special reports
• The Year comparisons report has been completely rethought
• There's a fast way to transfer data from one computer to another
• Your Remembered reports are immediately available everywhere you can build a report
• And more!

So this will be a long blog post! But you can skip all that text and download here; and let me know if you have any problems, either on Facebook or by email.

Update: 21.0.1 was released soon after, with a few fixes:

• The range of Mediterranean Flycatcher now correctly includes much of Africa down to Namibia.
• Species info is now far more useful for "sp." taxa.
• An error message when deleting a location (harmless, but very worrisome!) is resolved.
• Browse by species makes it clearer when there's a group or subspecies sp.

eBird/Clements 2026 taxonomy

The eBird/Clements 2026 taxonomy was released earlier this week, and Scythebill 21.0 automatically upgrades your records for you. For all the details on the release - 28 splits and 4 lumps - visit the eBird article .

Scythebill uses checklists to automate away much of the difficulty in taxonomic upgrades, but one of these splits is particularly thorny. Willet is split into Prairie Willet and Saltmarsh Willet, and these birds overlap in range - Prairie Willets will even oversummer alongside breeding Saltmarsh Willets! Outside of "safe" Prairie Willet range (much of central and western US and Canada), you will likely have records that Scythebill cannot assign on its own. If you have photos, this article may be of help (its "Eastern Willet" is Saltmarsh, and "Western Willet" is Prairie).

For birders in southwest Europe and African birders, the Spotted Flycatcher and Mediterranean Flycatcher split may pose similar difficulties, though time of year and exact location will be of some help, at least in Europe, as you work through the split.

Birders in South America may also be puzzled by the Giant Hummingbird split - some records (especially in central Peru) may be unresolvable without either good photos or careful consideration of time-of-year (Southern Giant-Hummingbird is migratory, while Northern Giant-Hummingbird is resident).

Once you've upgraded, though visit the Splits and lumps report in Special reports to see how the update has affected your lists:

As part of this update, there are four new options for name translations in Preferences:

• English (AviList)
• Afrikaans
• Catalan
• Ethiopian

AviList 2026 taxonomy

Scythebill 21.0 no longer supports the (now defunct) IOC taxonomy, but in its place is the AviList 2026 taxonomy, released a little more than a week ago.

I'd hoped that 2026 would bring virtually full convergence between eBird/Clements and AviList. But while all the new splits and lumps in Clements are matched species-for-species in AviList, there's still about 30 species-level differences (and many more subspecies differences) between the two checklists. So, until they've completed this convergence, I'll support AviList alongside eBird.

So AviList now sits right in the taxonomy chooser, just below eBird/Clements. Just as you could with IOC, you can switch between the two taxonomies at any time.

You can even visit Splits and Lumps and see the difference between AviList 2025 and 2026 for your list!

One difference from IOC: AviList is not currently publishing any vernacular names aside from their base English list. Scythebill is covering this by using the eBird name translations for AviList as well, though this leaves gaps for taxonomic differences (e.g. AviList's Purple Swamphen).

Timeline report

Scythebill has long had a "Big day/year" report, but it didn't do much and hadn't received any attention in awhile. That report has been completely rebuilt as a new Timeline report in Special reports. It gives you the broad time view of your entire list:

At the top is a graph of your list as it grows from early days to today, with milestones automatically highlighted (and clickable!). The bars below the line show how many species were recorded in a year, with lifers in a bolder blue. As with anywhere else in Scythebill, you can change that report to see how your Western Palearctic or ABA Region or country list, etc. grew through the years.

Hover the mouse anywhere over that line and you'll see a popup with information about those lifers. And You can also drag across the chart to zoom into a shorter view.

At the bottom left is a chart of the "big years", with how many species were recorded and how many were lifers that year. You can sort by total count, most new, or chronologically. Or, you can click for a "days" view and see all your biggest days. Click one of those years or days, and you dive right into the data for that year or day, with lifers pre-highlighted.

There's even a little "copy" button in the upper right of the chart if you want to share your graph with someone! (It copies the image into the clipboard.)

Year comparisons

The Timeline report isn't the only one that got some attention this time. The overhauled Year comparisons report (also in Special reports) gives you a data-packed way to look at your own records from years of birding a local "patch" - whether that's your backyard, a favorite park, or (for the Big Year folks among us) an entire region.

There's a lot of information here. The top has the usual report-defining section (here, San Francisco). Then, just below some options for the page, there's a so-called "spaghetti" chart with each line representing a different year and how many species you'd reached by by that date. (No, I haven't been getting out enough this year.)

Below that is a table, year-by-year, for all the species on that list, and how often they were seen each year, represented by the presence or relative darkness of that color square. That table can be sorted in multiple ways - taxonomic, most frequently seen, "longest unseen" (birds you haven't recorded in a long time), and others. It can also be filtered - to show just what you added to the "patch" list in a given year, or what was missed altogether that year.

And on the right is a time-of-year bar graph for a selected species, with an "all years" view up top, and a per-year view below. It shows first arrival and last departure dates, as well as peak presence.

Transferring data from one computer to another

All you've ever needed to do to transfer Scythebill's data from one computer to another is copy a single .bsxm file. But while that's trivial for some users, for others it's a challenge - do you email it to yourself? set up file sharing? get a thumb drive?

Now, the "Send to phone" feature has been extended. That File menu item is now Send to phone or computer..., and there's a new Receive from another computer... option. To send, run Scythebill on both computers:

• On your original computer, choose Send to phone or computer...
• It shows a 60 character code; copy that, and email or chat it to yourself. (Leave that window up!)
• On the other computer, choose Receive from another computer...
• Paste that code in, and click Receive 

If the two computers are on different networks, click "Use encrypted cloud transfer" on the first computer (which gives you a different code).

Remembered reports, everywhere

As a reminder, in "Show reports", you can click Remember... to save a particular report. That adds that report to the front page of Scythebill, and makes it important enough for "New for" columns in various places. Now, that list of reports is available on any reporting page - so while you're on (for one example of many) the Lifers map, there's a new Remembered reports menu just left of the taxonomy chooser in the upper right part of the screen. Your most important reports are just a couple of clicks away, everywhere.

Better inline maps

Scythebill 20.4 introduced single-keystroke in-app maps for species. But state-level information about range was hidden behind double-clicking on that map. Now, state information is shown immediately, even across countries, like for Palm Cockatoo:

... or Sulphur-bellied Flycatcher:

These make it much easier to understand the range of species at a glance.

And more...

The "Species Info" popup works far better when a subspecies is selected - instead of showing just the information for the subspecies, it shows all the species information while lightly highlighting the selected subspecies:

The old UI for choosing a subspecies on an existing sighting had a dialog for displaying all the range information; that's gone and replaced by one of these popups, and the UI for entering a sp. or hybrid doesn't use a dialog anymore either.

If you enter a new location, and geocoding doesn't find a lat/long, you can now select one for yourself on a map (pre-zoomed to the known parent location).

The map data overall has been improved and stored in a faster format. Large inland lakes now appear in state mode, and lat/long lookups against it are now much faster.

Some parts of Scythebill were very low-contrast in dark mode; that should be much improved.

Finally, the Linux version of Scythebill runs "detached" when you launch it from a terminal - quitting the terminal won't stop Scythebill.