The Black Fronted Zebra Finch has been around in Australia since it was first discovered in 1965, so basically there is nothing new in what I am about to write. However, as it is virtually unknown in Europe, I thought some of you might like to read about this mutation anyway.
The mutation is recessive, and is best described as a normal bird that has a breast bar that extends up to the lower beak, completely black tail coverts and a black line from the beak to just below the eye. Females show the same characteristics, except for the breast bar.
Below is a picture I took in 1996 of a bird bred by Queensland breeder Col Evans.