The etymology of Latv. putns 'bird'

So yesterday I was reading up on Sihler's account of ablaut in New Comparative Grammar of Greek and Latin. He listed the attested alternations for PIE *pet- 'fly, fall':

e-Grade

G πέτομαι 'fly'
L penna 'feather' < *pet-neH₂
Ved. patati 'flies'

0-Grade

G ποτή 'flight'
G ποτέομαι 'fly about'
Ved. pātayati 'makes fly'

Zero Grade

G επτόμην 'fly' (Sorry about the breathing mark)
G πτερόν 'wing'
Ved. apaptat

I got to wondering whether this root appears at all in Baltic. I could not think of any examples in e-grade or o-grade (A verb for flying or an abstract substantive for the concept is not apparently attested to my mind). Then I thought of Latv. putns 'bird'. I checked the entry up in my etymological dictionary. Apparently, the traditional theory connects L puer 'boy' and Ved. putrá- 'son, child', G. πω̃λος 'pony' to Latv. putns 'bird' and Lith. putýtis 'chick', paukštis 'bird'. A root *pōu- : *pū/u- is furnished (the grade of *pōu- probably on the evidence of G πω̃λος. But if these semantically varied items are to be connected together in some way, Lith. paukštis must be thrown out of the list. The outcome of *-ōu- in East Baltic is evidently -uo- (with the loss of the second component of the diphthong) on the evidence of Latv. guovs 'cow' < *g^wōu- (cf. G βου̃ς 'cow' and Ved. gāu-).
I think, then, it might be better to somehow connect Latv. putns and Lith. putýtis to a *pet- root in the zero grade. One might think the source of -u- in this word is a 'schwa'-like vowel in the vein of G. ιχθύς 'fish' from the so-called 'thorn cluster' of *dhĝhūs 'fish', or perhaps the anapytxis of L pōculum < *pō-tl-om.
This may not be really necessary, as Latv. putns can be thought of as being originally part of the paradigm of a heteroclitic athematic noun with cognates such as G πτερόν, German Feder, and Hittite pattar. Thus an original proterokinetic *pét-r-s / *pt-né-s could have its zero grades mixed up and generalized (cf. the thematicized πτερόν with a generalized full grade suffix -er). A later form *petunas or even more likely *ptunas (with generalized zero grade -un- in either case) could have been metathesized into * putnas > Latv. putns.
Then again, this could all be just a little bit far-fetched:)

Le Nouveau Bloggeur

After much thought I have decided to start one of these...