So we got two duckings about a year ago to raise along side our chickens. When the duckings were still young one got carried away by a predator which left one lonely drake. Our big rooster seemed to look out for him and the hens soon allowed him to join their flock. As he got older he began to cling to one hen in particular, she is a 5 year old barred rock, the oldest of our birds and the head hen. Everywhere she went, he was not far behind. We though nothing of this odd pair for a while, however, a few days ago the hen got a rather large injury and had to go to the vet. While she was away the drake got very anxious and followed us around while looking for her. When she returned he became more attached then ever, yelling at anyone who gets close and chasing off other hens who are interested in her wound. Her medicine makes her drowzy, yet he will not leave her side. This behavior caused us to wonder if this particluar duck has chose a lifelong mate or has just made a huge bond with this hen. From what we've seen he has never mounted her or tried to breed, but he does nuzzle her face and follow her everywhere, and he seems very concerned about her current illness. If anyone has any sort of explanation of this behavior that would be much appriciated.