Sweet emu turned aggressive

[Stinky]

I’ve had my male emu for around 4 years and got him at a couple months as a friend for my female emu who I hatched, the female has always been the stand-offish, moody one and the male has always been cuddly, calm, and loved people, they havnt mated in the years they’ve been together and I just assumed she didn’t like him because she was human raised for the most part, we unfortunately lost her to some animal around Christmas time, we’re thinking coyotes, and since then my male has been getting progressively more aggressive and mean, I’ve never heard him growl or hiss before and he’s trying to kick when anyone comes near the fence, I don’t blame him and I’ve gotten more babies so he isn’t alone but it’ll be a couple of months before they can be put together, is there anything I can do for him in the meantime to calm him down or make him feel safer?