Broadly: all the tea-leaf reading here about "works in one browser or another" is pretty much absent any analysis of why it might work in one place or another or what's really happening. So:
When the eBird map looks up a bird name, it's sending a request that looks like:
https://ebird.org/ws2.0/ref/taxon/find?key=[REDACTED]&locale=[YOUR LOCALE]&q=grey+plover
(The key is easily discoverable by examining HTTP requests, but didn't want to put it in this doc.)
With that request above, if locale=en ("English"), you get nothing. If locale=en_UK ("UK English), you get Pluvialis squatarola.
So where's the locale come from? It happens to be generated in the HTML for the originating page, back on the eBird servers. (View source for the eBird map page, and search for "sppLocale".)
Now, I can't look at their source code, but I can experiment a bit. And what's pretty clear is:
- If you're logged-in to eBird, they take the species name display at
https://ebird.org/prefs and use that.
- If you're not logged-in, it's using the "Accept-Language" header to figure out what language you'd most like to see. (It's possible they look at some other settings too in the absence of or in preference to Accept-Language; I can't know that.)
This page has a pretty good overview of per-browser settings that effect this
https://www.w3.org/International/questions/qa-lang-priorities . I was able to verify (in Chrome) that changing my preferred language from English to English (UK) made the map suddenly find results for Grey Plover.
So when people are seeing "Ihttps://www.birdforum.net/images/smilies/pint1.gif get different results in different browsers", it's entirely one of:
- You are logged-in with one browser and logged-out with another, and the eBird preferences are different than your browser's language preferences, OR
- Those browsers have different language preferences
