Hummingbirds

After a glorious day yesterday, with sunshine, a light breeze and blowing clouds, following a half inch of rain overnight, today is back to is it raining or is it just fog?   Yesterday I had to take advantage of the unseasonal warmth and sun and went for a bike ride.  All I did in the garden was to gather up the wetted grapevines and wind them into a chunky wreath.  Today it is really too wet to do anything, but I noticed the hummingbird feeder was empty so I filled it.  We enjoy the hummers in the garden and try to plant flowers they will enjoy, as well as keeping the feeder filled.  This time of year with fewer flowers the feeder becomes more critical and I regret letting it get empty.  Our birds may have moved along to someone more obliging.  I am not sure what the migratory pattern is of the local hummingbird population, but they disappear for a couple months every year, leaving late January or sometime in February and reappearing in April.  I assume they must nest somewhere else, but where?