What Is This Noise?

[Lov'emSouthernEggs]

We have brought home two Spangled Ham. Roos. They are beautiful and about a year old. They crow like roosters should but they make a growling noise. What is the growl and what does it mean?

It doesn't seem to happen when they are near anyone else. They seem to be by themselves when they do it. Not fighting or anything. Any ideas?

Thanks!

 

[gritsar]

A growl usually means Watch out! There's danger around! Even if that "danger" is just a human approaching.