For a small amount of ducklings, for 0-12 weeks you can use one or two 40-65 watt blue tinted bulbs, usually found at home improvement store, research has shown blue light is more gentle on the ducklings eyes and can reduce the incidence of feather eating. For more ducklings or just a larger...
I'm in Portland, OR area, have have ducks for a year now, previously had chickens. As long as the ducks have a dry sheltered area, with clean drinking water, they should be fine. I increase the amount of corn in their feed mix during the coldest months since it provides more fuel for heat...