...it's not.
They are an invasive, non-native species, found throughout the entirety of North America, and much of, if not the entirety of the West Indies - Raffaele et al in "Birds of the West Indies" note "range is expanding" and his map from ~1998 already shows them in most of the West Indies. Plus, if you saw 10+ of them, that doesn't make much sense coordinating with your rarity evaluation.
On what island were your photos taken, by chance?