Glad to meet you, Valentino. Here is an article on improving predator protection and another on electric fencing, in case you want to go that route. People do go beyond those main things, by adding wildlife cams and lights so they can check on activity, both of their own birds, but also of predators in the area. See this post, and this lengthy discussion
Best wishes with your 3 drakes, and all your future birds!
Welcome to the coop! I use the Forums and Articles tabs at the top of the page to do research. You can get lost for hours. It's nice to know you are minutes away from getting help with questions and emergencies!