While it is clear that NYC is an exceptionally "isolated" area
for bees, free on most of the known pests and pathogens that
are common in most beekeeping areas, I have bee-lined 4 hives 
in Central Park, and know that there is at least one more that 
I have not yet pinned down.

> Donovan, in his book on bee lining, recommends warming the honey.

In a dearth, one need not even warm the honey.  In a bloom,
warming will not help at all.

Donovan was yet another pre-varroa bee-liner, and his "methods"
were absolutely dependent on the large number of feral hives.
In short, the bulk of what passes for bee-lining "technique"
can be directly replaced with tossing rocks in random directions.
In pre-varroa days, a randomly tossed rock was very likely
to "find" a hive.
 
Given that CCD is clearly caused by multiple invasive exotic
pathogens, it is not at all surprising that isolated hives 
and areas "off the beaten path" to be as CCD-free as they 
are varroa-free and Nosema-free.  Nothing spreads diseases
and pests of bees around like bees on the move.

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