We have a pair of Australian Black Swans which are aprox. 2 1/2 -3 years of age. We have had them for 2 years. We also have what I believe to be male and female mutes that are 2 yrs of age which were rescues. They have all been on the same pond for 1 year. Recently after a day of what we believed to be mating activity b/t the 2 Mutes, the Mute that I believe to be a female, chased the male Mute out of the pond and will not let him reenter without a fight. She has also started to spend a lot of time with the female Black Swan. Will Blacks and Mutes interbreed and is it most likely that I have 2 male Mutes? What I believe to be the female Mute is the only one that has not been DNA sexed.