World birds restricted to an island (1 Viewer)

I wonder what is the number of species that are restricted to one small island. At which point in gathering a world list you find yourself having to hop through a thousand small islands to clear those up? Is this in hundreds or thousands? I have no idea, but I am pretty sure there is a guy in his armchair out there, with a huge table (hopefully digitized by now) which can export this information on a whim, right?

I understand this is not as straightforward as it seems. At a certain size of an island, its island quality becomes kinda irrelevant, visiting Japan is no different from going to Korea for all practical purposes, so the question should probably include a threshold on the size of the islands. Britain technically has an endemic bird (setting aside its practical untickability), but whi cares that it is a island if you can take a train there? Some birds can be found on several adjacent islands, which makes them no less difficult to get, so that should be taken into account as well... you get the gist it's complicated, but a general idea could be probably approximated.

Not that I am anywhere close to this point, but this would put an interesting light on the high-ranking listers' numbers - and I am generally just curious about silly numbers

You might find this useful, though it's rather old now:

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1474-919X.1990.tb01036.x

They define islands as being smaller than 20,000km2 (or New Caledonia and smaller).

Ross McGregor said:

You might find this useful, though it's rather old now:

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1474-919X.1990.tb01036.x

They define islands as being smaller than 20,000km2 (or New Caledonia and smaller).

Click to expand...

Interesting! They say over 1750 species, which should now be even more, because recent splitting is very much biased towards separating island species from each other.

However it is not completely clear, what islands does this number take into account. The 20.000 km2 is only in relation to one database they use, but they explicitly state that for this study, they added "Madagascar, Japan, New Zealand, Taiwan, Sri Lanka, Cuba and those within Indonesia and the Philippines" - but it is not completely clear if any of this relates to the number 1750, which is stated only as general observation. Later in the text, specific numbers are given only for threatened species.

But as a starting point it's interesting and it is a pretty high number!