I experience this most acutely on my early morning and late afternoon bike rides to and from school.
As you know, most of my ride is along the river, which I have found out is the Nakdong river and is quite an important river in South Korea. I have been enjoying this as there are quite a number of birds and always something interesting to see along the river. There have been a lot of mallard ducks on the river and also some wagtails: they look a bit like our pied wagtails in South Africa but the black and white pattern is slightly different, I think they are Black-backed Wagtails (photos courtesy of 'the Internet'). And of course the ubiquitous and vocal magpies!
So this morning for the first time the river has started freezing over: it is not entirely frozen but most of the surface has a thin layer of ice over it, so I was asking myself: Where do the ducks go? I can dress up in my thermal underwear, beanie, scarf, windproof-gloves, layers of jerseys, coat and face mask (Now I know why the Koreans wear them - it's for the cold!) but the ducks can't, where do they go? And where do they sleep? The nights are even colder!
Out of interest, there is a bit of information on Sangju on Wikipedia, take a look: http://en.wikipedia.org/wiki/Sangju