I think. Medium sized woodpecker type bird.
This tree is a place where they story their acorns.
Breve descripcin de lo que observaste
Nine families of largely arboreal birds make up the order Piciformes, the best-known of them being the Picidae, which includes the woodpeckers and close relatives. The Piciformes contain about 67 living genera with a little over 400 species, of which the Picidae (woodpeckers and relatives) make up about half.