hi, I went to varadero in January and had a hard time finding birding areas, one good place was the zapata swamp but had a hard time communicating what we wanted, we ended up spending too much money and ended up at the tourist trap of the crocodile farm but still saw some good birds. People gave us strange looks when we said we wanted to see birds. some birds we saw in varadero were palm warblers, magnificent frigatebirds, brown pelicans, cuban emeralds (at the resort). cattle egrets everywhere. at zapata we saw nartern jacanas, purple gallinules, common moorhens, common ground doves, west indian woodpecker, loggerhead kingbird, northern parulas, just to name a few. house sparrows are abundent. I recommend the birding book birds of cuba to help you out. I would be curious to find out if you have any luck, please post when you get back.
christie