I've been wondering about something I've been seeing swans (as well as Canadian geese) doing... I've seen them moving in a trampling manner sometimes before sinking their head into the water to eat. Is it to break up the vegetation they eat? Is it something they do out of necessity? I just find it interesting that I haven't seen it done before, but I suppose I might just not have noticed it as much until the kids have gotten big.

Also, does a family sometimes lose a few members temporarily? One day, we saw a couple groups of swans, with neither one having how many the local family has (which is 8, including parents). One was closer with 6, and if I remember correctly, the other one had 4 or 5.

Thanks.