White-collared seedeater

This must have been one of the shiest bird I have photographed in Costa Rica as it always gave me its back. In the third pic you can sort of see his face but is not a very clear picture.
10-11 cm long. Black short beak, strong and conical. Head, wings and back black. Belly and rump are pale tan. Chest, parts of the neck and speckles in the wings, white.