I'd say that a nuc is or can be a self-sustaining colony if a colony is defined as a laying queen with a bunch of brood and workers on comb.  Sure they will cast many crowding swarms but they are likely to do well and overwinter in many locales.

>>We studied in detail only nests in hollow trees. Because we considered nests in man-made structures as unnatural...

Man-made structures may not be natural but I've removed colonies from spaces smaller than a nuc.  I always marvel and try to study, at least superficially, how the bees adopted their nest to their unnatural cavity.  Their decision-making process is most interesting.  For instance, unnatural cavities make thermodynamic control often more challenging -- bees will often build buffering curved combs in sections that prove particularly drafty.

Dormer structures often result in the most intricate nests.  One had the combs spiraling around various rafter and jack beams up towards the ridge...  What teamwork! [And what a long, nightmarish removal! :)]

Waldemar

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