@maxkirsch thanks for making this change
last night, I committed http://www.inaturalist.org/taxon_changes/24850 which elevated Circus cyaneus hudsonius to Circus hudsonius
Is there a reason why the observations haven't successfully moved from Circus cyaneus (5170) to Circus cyaneus (559064) + Circus hudsonius (558446)? This should happen automatically if atlases were made

Wait, never mind - now it looks like observations have been swapped (I guess it was just a little delay)

I think there was just a lag in moving the observations over - looks good now

Figured it would be better to put the explanation for the period earlier today when harriers in North America were labeled Hen Harrier here:
After loarie swapped Circus cyaneus hudsonius (236973) into C. hudsonius (558446), kokhuitan committed a taxon swap of C. c. cyaneus (509495) into the old C. cyaneus (5170) and changed its name to Hen Harrier (rather than swapping the subspecies into a new C. cyaneus); I left a comment on that swap explaining that, for future reference, when a species is split, a new taxon should be created for each post-split species on iNat (rather than swapping the old nominate subspecies into the old, broader species), after which someone (presumably kokhuitan) deleted that split (the missing Taxonomic Swap 24855; in my opinion, that was a bad idea, given that it obscures the history of the taxon on iNat - better to have a record of the occurrence of an incorrect taxon change than to have no record at all). I then committed a split of the old C. cyaneus into the new C. cyaneus and C. hudsonius.