Sounds like they are getting serious about breeding. When I had 3 pr of MM, each pair behaved slightly different as far as human interaction is concerned. Close observation skills soon shows the cock birds that will or wont draw blood. I found that transferred aggression towards the hen a major concern.
I have a friend who had about 10 prs of Majors, all long time breeding pairs, would experience on rare occasions the cocks savage or even kill the partners. In 1 season this happened 2 times, the hens suffered mainly upper mandible damage, then he said that the MM had not shown any visible aggression over the previous years. I have spoken to a local avian vet about this phenonimum, he stated that Majors are well known for this and he would see a couple of hens each year. He even suggested that making a nest box with a baffle type arrangement inside and having an extra entrance might give the hen a chance at escaping.
