I have 2 Isa browns, they were purchased about 2 months ago as chicks. I thought this morning that I heard one trying to crow, but I am not for certain. I know that the isa brown females are darker brown, which I do have 1, but the other seems to be lighter in color, with brown. It also has a larger tail then the other. I only heard the noise it made once this morning, but I also heard the noise a few days ago. I'm not sure if one is pecking the other to make the noise or what. I have 2 other hens that try pecking at these 2, so they get to stay in at night where it's warm for them. I never see which one it is making the noise. I've included a picture of them both. The darker smaller one I know is a hen. Sorry for the quality of the pictures, I couldn't get them to hold still!