In such cases in the Hebrew Bible where the reading diverges from the text, what is read is call qere (or "kere") and what is written is called ketiv (or "kethib"). Not all instances of qere/ketiv are to avoid pronouncing God's name; some are just grammatical.
Saying "Adonai" instead of pronouncing the tetragrammaton becomes completely automatic when one learns Hebrew. There's nothing quite like it in English (saying "namely" for "viz." or "kernel" for "colonel" are perhaps analogous).
I'll do my best, but I just discovered the connection myself. This word apparently comes from the Greek for "rumor" (or "report") and "avis," so a second meaning for cledonism appears to relate to the ancient Greek practice of augury of birds, mostly through flight and song. Have you heard of this, sionnach, or anyone else who's familiar with ancient Greece?
r_t: This is what my little researches turned up -
Cledonismancy or cledonismantia:
Divination by first words uttered upon meeting friends, after salutations., Derived from ancient Greek kledonisma a sign or omen.
1855 Edward Smedley in Smedley et al. Occult Sci. 327: cledonism, Or, in full, Cledonismantia, is good or evil presage of certain words uttered without premeditation when persons come together in any way;
it also regulated the words to be used on particular occasions. Cicero says the Pythagoreans were very attentive to these presages; and according to Pausanius, it was a favourite method of divination at Smyrna, where the oracles of Apollo were thus interpreted.
on edit: I assume you are referring to the Wikipedia part of the entries here
My knowledge of Greek is zero, but even taking it at face value that κληδὸν has a secondary meaning 'bird', it seems fairly clear that it is the first meaning (rumor/report) which drives the etymology. In other words, the last sentence, equating it with ornithomancy seems to me not to have been justified by anything that has gone before.