This is the 14314th most frequent Polish word.
przebywały
"Przebywały" means "they stayed" or "they resided."
Here, 'przebywałyśmy' (we stayed) denotes presence or habitation in a location during a specific time period.
Na wakacjach przebywałyśmy nad morzem.
During the holidays, we stayed by the sea.
In this sentence, 'przebywały' (resided) refers to the presence of the birds in a specific area during a period of time.
Przez całą zimę ptaki przebywały w ciepłych krajach.
Throughout the winter, the birds resided in warm countries.
Here, 'przebywały' (stayed) indicates a temporary stay or presence in a given location.