I've found this in 'Folktales of Ireland' compiled by Seán Ó Sullivan. He's talking about the first story in the book called 'The Fox and the Heron', which was recorded by Brian MacLochlainn in 1935 from Antoine Ó Maoláin who was from Baile Nua, Cleggan in Co. Galway. Unfortunately once again, the story is presented as a direct translation from the Irish, but the original version isn't available.

- "In the present story, the Irish name for the heron is Máire Fhada (Long Mary). Many other birds are known by human names in the Irish language."

Would anyone know of any of the other names he is referring to? And would anyone know of another version of this story in Irish?

Check out this website, a Fhrainc:
http://gofree.indigo.ie/~cocaomh/English-Irish%20Dictionary.htm
Lots of interesting bird name info there, arranged by their English names.

And for the names in reverse arrangement (i.e. arranged by their Irish names):
http://gofree.indigo.ie/~cocaomh/Irish-English%20Dictionary.htm

This site compares the names for certain birds (a smaller selection than in the above lists) in the various Celtic languages:
https://www.omniglot.com/language/celtic/connections/birds.htm

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I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.

Go raibh maith agat, a chara.

I didn't see any normal given names in the list linked, but I think I know what you mean. I have heard animals with names like Seán something and Máire something before somewhere
Was it caterpillars??

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ЯГОН ТОҶИК НЕСТ ИНҶО???