I still have an 8yr old Runner drake having the time of his life 2 of his girls are now in with the Muscovy because he chewed their heads one got infected. My 1 yr old is of course in his prime. It really depends on the drake and this little one that got so chewed up was in the wrong place when it escaped the pen it was in. Some drakes will even kill ducklings so this one was lucky. I've never had one of my drakes injure a duckling but I am very careful not to ever leave them along with the flock without I am with them. Until they are at least 3 weeks old and mama is still with them. Most of the time the drakes are scared of the ducklings.