Mating Teals

I visited Sekino-e again today both in the morning and in the afternoon. The main flock of the Common Teals has moved from the first area where I found it yesterday to the other flooded field on the opposite side of the village. I saw a pile of a drake's body feathers left on a dike. I guessed a raptor had come and successfully caught it and made the flock moved away from the area to another place. I sat and watched them getting more and more active in the late evening and again, I have witnessed the mating of these wild ducks in this very early December.

These guys have gotten very active and started swimming around the females in circles.

Here's the 'display' of the drake. These 3 steps happen very fast.

And this is the final step where the bird raises its crest and chest and gives a brief whistle call.

Does anybody knows if it is normal for ducks to mate during migrating season, while they're far far away from their breeding ground. What if the females get pregnant during the migration? That doesn't sound so good though. Hope this is not again one of the global warming effects.