> ..."The thermology of
> wintering honey bee colonies". The study compares an insulated hive
against
> a heated hive and an uninsulated check hive.

It's a good article and I happen to have a copy or two of it around here
somewhere.  Tibor Tzabo followed up that work a few years later while at
Beaverlodge, doing some studies with a similar name that compared several
wrapping and entrance styles and demonstrated the importance of appropriate
controlled ventilation.

> The results may surprise many beekeepers.

...And fool some Northerners too if they listen to people who are too far
south, or to beginners who have been lucky a year or two.  It fooled me, and
taught me to read those ivory-tower studies more carefully to see what is
really being said.  (see below).

I read that article during my early years of beekeeping.  I took it at face
value, and it gave me false confidence.  That false confidence cost me quite
a bit of money and work until I realised that maybe my neighbours, who
wrapped well and faithfully, knew something that did not show up in a small
one-time experiment done under artificial conditions, and I learned to wrap
properly.  At that point I stopped having as many problems in winter and
spring.

I've learned on careful reflection -- and bitter experience -- that this
well respected and often quoted study does not actually say what it seems to
say, and, further, does not really prove what most people think it proves.

Au contraire!

Reading carefully, to me the most significant observation from the study is
this: "A colony protected by insulation will have a less compact cluster
that will fluctuate more in size with temperature change than a cluster in
an unprotected colony".   This allows smaller colonies to cover more area,
and allows any colony access to more food.  That can mean the difference
between living another day and dying some dark cold windy night.  Death is,
after all, final, and makes the other points moot.

Another significant point is this: "A cluster held for long periods under
freezing conditions declines in strength...but is slower in insulated than
unprotected colonies".  This observation is an admission that protection
noticeably reduces loss.  Unprotected colonies are weakened more by winter
conditions.  Weak colonies die in spring if the spring is late, which it
often is.

The article finally says "Under *normal* winter conditions, either insulated
or uninsulated colonies *should* _survive_ at Madison Wis".  (Emphasis
added).   Although that sounds encouraging, and seems to suggest that
northerners can safety forego wrapping, I realised after a while that
"should" is not good enough for me.  I need certainty.   Also I realised
that "survive" is not good enough for me either.  I need "thrive"...and, as
for "normal winter conditions", ask any farmer or weatherman when he ever
last saw a "normal" winter...  FWIW, right now we are having a heat wave; a
year ago it was minus twenty.

It is easy to forget that just takes one abnormal event to tip the scales
and cause colony death in marginal conditions.  That is the end of it.
Barring that, prolonged cold weakens both the bees and the colony.  I've
personally observed that poorly wrapped colonies yield fewer spits in the
spring, even when survival is comparable. to well wrapped hives.   Who, but
a researcher, can risk such losses?

When we consider also that we may not have the same strain of bees, or the
same conditions as that particular yard at Madison, and that perhaps the
hives they selected were not just any old average hives, and maybe we don't
manage our bees in quite the same way during the summer, drawing conclusions
that could terminate our careers as beekeepers seems (in hindsight) to me to
be somewhat rash.  While it is, indeed, an interesting study, I'd not advise
believing it applies to every real-world situation.  After all, unless you
are a researcher, the death or weakening of colonies is very bad news.

Wrapping is cheap and easy and it is good insurance in northern areas even
if it proves, in retrospect, to have been unnecessary some years.

Once again, the rule is caveat emptor.  This is just as true when reading
studies as it is in advertising.

allen
http://www.internode.net/HoneyBee/Diary/