>>The most common reason to fly in the winter would seem to be for a 
cleansing flight.

Right. Although my bees had been making collection and defecation 
flights for 2-3 days prior to the snow fall.  I did look and did not 
see any bee stains on the snow.

>>There are also bees performing an undertaker role by removing their 
deceased sisters from the hive creating the litter in the snow. 

I looked at the bees flying out of the hives and none were dragging 
dead bees.  All dead bees had been taken out on nice days prior to 
the snow.

>>Water might indeed be necessary to dilute food at times but it is 
perhaps not the primary need for these winter flights.  Water can be 
obtained from condensation and other external melted sources unless 
it is extremely cold.  

I observed a line of bees eagerly taking up water from the melting 
snow on a hive's entrance.  My hives have good top ventilation and 
the hives don't have much condensed water inside.  Increasing brood 
requires a lot of diluted honey. 

>>I would NOT put a division board feeder with water in the hive 
because of the "thermal load" it would impose on them.

The division board feeder does not need to be full - even 1/8 full is 
plenty for what the bees can use - and it would take the place of the 
last frame (away from the cluster).  The water, if anything, just 
like in greenhouses, would act as a thermal equalizer absorbing heat 
during the day and releasing it at night.  Bees would take up the 
water and transfer it into cells in or near the cluster during the 
day's warmth or they'd right away use the water to dilute the honey 
and store that for later use.

As far as cold temps, even frozen water will not get colder than O 
deg C.  When it's -10 deg C outside, it's -10 deg C in the hive away 
from the cluster.  I don't think it's an issue.

Waldemar

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