Blue and Yellow Tanager - Thraupis bonariensis
Blue head and chin with grayish-blue upperparts and bright yellow under parts. Adults distintive; note contrasting yellow rump. Drab juveniles and immatures more confusing but usually have at least a little blue-gray on head and wings; also note bill shape and behavior.
Song a repetitive 2- or 3-syllable series of notes, occasionally very loud and wiry in quality, for example: "chew-see-wee chew see-wee chew see-wee"
Calls a loud, ringing "tchee", also a hesitant "ptee-chee-tew".