MATED PAIR

I forgot about these two yesterday.  I assume it's the same two that have used my brothers pond during mating season for at least a few years.  I have never seen them with young, so I don't know how successful they are.  There is a slow moving river just behind this pond.  They hop from one to the other.  So I don't know where their nest is.
A couple of years ago, I observed a strange behavior one of these.  Like a small child that thinks you can't see them if they hide their face,  this goose would put it's head under the water whenever I was watching it.  When I first saw this, it's neck was straight out upstream in the river under water.  I thought it was caught on fishing line and dead.  When I came back, it was swimming around.  When it saw me it stuck it's head back under the water.  I kept saying, I can see you.