Roughly 25 species, mostly in Calidris which might be split up into several genera.

The former is taxonomically confusing, with species having been split and remerged in the last years.

The species were split in 1931, only to be subsequently re-merged by most authors.

For identification purposes, the species can be split as follows:

Since the two species were split, a number of other differences, in appearance, habitat and food, have also been discovered.

Some authorities suggest that this species may be split into several separate species.

However, just how the species should be split proved controversial.

More research will be done, and this species may yet be split into several.

Thus, the species might be split into several in the future.

Some authors believe the species should be split into separate species.