just based on from what i can remember from the early game i feel like blathers is probably on the island to do a field survey on the local fauna and the paleontological significance of the area. so anyway cut to blathers back in animal city doing his presentation during the yearly conference. the powerpoint concludes and he asks for questions.
man in crowd: sir. sir may i ask–what is that in the background of the fourth slide
blathers: eh? oh! well, that’s one of the paintings which was kindly donated to me by this island’s inhabitants! isn’t it grand?
man in crowd, as his fellow academics begin to murmur: yes is…is that the…is that the real mona lisa, sir?
blathers: by my accounts i do believe it is!
man in crowd, now having to yell over the commotion: sir are you aware that that painting was stolen from the louvre in a highly publicized heist. it’s all over the news. how are you not aware of this
blathers: wot