I'm not familar with this word, as used in this context, apparently it means (in Irish English) to land - tar go talamh. The problem I have is that he uses the verbs to land and to pitch, one after the other in the same sentence, so I'm not sure how to put them into Irish. Do they mean the same thing or is there some kind of nuance between them ? Here's the context -

The first example -

And then he realised
that it was all the birds of the air were coming
and they were darkening the sky.
And all the birds came and they pitched all around about -
hundreds, thousands of them.

Agus d'aithin sé ansin
a raibh siad ag teacht gach uile éan an aeir
agus a bhi siad ag dorchú an spéir.
Agus tháinig na héin iad go léir agus tháinig siad anuas sa spéir ar gach taobh mórthimpeall -
céadta, mílte acu.

The second example -

And the eagle gradually grew larger
and finally landed in and pitched.

Agus d'éirigh an fiolar ní ba mhó diaidh ar ndiaidh
agus tháinig sé go talamh faoi dheireadh agus.........?

The dictionary definition of "pitch"





But by another difinition it also means "dive". Like this nautical term in Teanglann.
http://www.teanglann.ie/en/eid/pitch

And birds can do both, climb and dive.

Unfortunately I don't think the entry in the Teanglann dictionary covers the meaning intended here. Perhaps Séamus Ennis was using language that is no longer used in quite the same way today. The translation that I've come up with is -

agus tháinig sé go talamh faoi dheireadh agus chuir sé faoi ansin.

Thank you all the same.

I don't know what the source of the quotes is, so I may be misunderstanding something, but in both cases the word "perched" would seem to make more sense than "pitched". Was it perhaps written by someone who was not a native English speaker, or could "pitched" perhaps be intended as some dialectical variant of "perched"? Bríd did excellent research, but saying that birds were "pitching" sounds odd. It's not uncommon to use the word pitch in the sense of something like a boat or a plane "pitching [about/forward]", but not as part of its natural/intended action (the context usually states or implies that some force like wind or waves is acting on the plane or boat).

The expression "come to earth" makes perfect sense in English in the sense of "land". Maybe it was once a borrowing into English from a Celtic language (there are a lot of those hidden in English).

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

Well as I mentioned above, this is Séamus Ennis telling a traditional story in Irish English. He was bilingual, of course and so it's a great pity that he didn't record it in Irish as well, as the various versions he heard and collected were obviously in Irish.

Assuming Séamus Ennis' English could've been better, or maybe he was trying to translate too literally from Irish, and from the context, I'd use "swoop" instead of pitch. And following the Teaglann definition of that -

http://www.teanglann.ie/en/eid/swoop

.. I'd say: Thug siad ruathar anuas.

Thug sé faoi deara ansin
go raibh eanlaith uilig an spéir ag teacht,
is bhí an spéir ag éirí dorcha leo.
Thug siad ruathar anuas ar chuile thaobh,
na céadta, mílte acu.




The eagle sounds confused.
Maybe it is written in the wrong order. If so then maybe:
... tháinig sé de ruathar agus thuirling sé.

Go raibh maith agat.

I'm thinking "to pitch" here is in the sense of "to pitch camp". I see from the dictionary it can be used intransitively - "to encamp"- which I didn't know. Obviously it's being used figuratively- "to settle for a while" or perhaps it's local usage.