This is the 3160th most frequent Polish word.
ranne
"Ranne" means "early" or "wounded" depending on context.
Here, 'ranne' is an adjective meaning 'early', describing 'ptaki' (birds).
Ranne ptaki śpiewają o wschodzie słońca.
The early birds sing at sunrise.
In this context, 'rannej' is the feminine form of 'ranne', meaning 'injured', referring to the deer.
Pomogliśmy rannej sarnie znaleźć schronienie.
We helped the injured deer find shelter.
Here, 'ranne' refers to 'early', describing 'godziny' (hours).