> We did some open feeding tests in late fall in Maryland.
<etc.>
> Under similar weather conditions, overall bee flight activity
> increased dramatically - more than 6 fold at one site.  However, we
> also experienced about a 6% loss in returning bees - some drowned
> and I suspect others were too old and weak to survive the feeding
> frenzy. My guess, from an energy expenditure and bee loss
> statepoint - we had an adverse impact on the colonies (at least in
> terms of individual bees). Whether the colony experienced a net
> gain or loss from the additional provisions is unknown.
 
If colonies surviving the winter is an indicator, then open feeding
has a huge positive impact here in Alberta, since open fall feeding
can reduce colony loss to virtually nil.  This is proven time and
again when some yards are not fed and return losses up to 100%
compared to the 10-20% loss in yards with feed.
 
The real question, I guess, is whether there is a better way. This is
probably a personal matter, depending on resources and time available
-- along with other factors.
 
In the sense that there is little spilling, leakage, or handling
involved, it is a very quick and efficient method.
 
In that the bees must find and retrieve it, it may have some
inefficiencies compared to having the feed delivered in the hive.
FWIW, we find that feeding in hive with frame feeders does not get
as good results as open feeding, since winter losses are higher (and
the work is much greater).
 
The huge plus is that anyone who can read a map, drive a truck, and
open a tap can do it, so if you are stricken at feeding time, any
neighbour can feed your bees.  Or, if you find all your help has
gone back to school and the weather is closing in, you can feed
2,000 hives in two or three days *without assistance*. (This is
assuming your drums are already in the yards and that you buy
pre-mixed syrup, and that you have a big enough tank for delivering
the syrup to the yards).
 
Among the negatives is the question of robbing and the huge cloud of
bees that results, potentially scaring neighbours.  Moreover, when
the feed runs out, if the hives are not full and the weather is hot,
severe stinging can occur in the neighbourhood.
 
Fighting can result if insufficient surface area is available on the
feeder and some hives decide to try to defend the feeder.  We use
about one open drum per 12 hives and that seems okay.  The drum need
not be full. Some use an abrasive Skil (r) saw to slit drums
lengthwise to make 2 trays with greater surface area.
 
Another consideration is protecting the surface from rain.  Water is
lighter than syrup and will float, effectively keeping the bees from
their feed until the water is finally taken in by the syrup.
Moreover, the dilute syrup at the interface is likely to ferment.
Therefore, a roof of some sort, suspended above the drum is
essential. This roof should be able to keep cattle, horses and
wildlife out, since syrup is attractive -- and lethal to them.
 
Open feeding is not advised if there are neighbouring bees within a
mile or so due to invasion from those hives.  There is the chance
that diseases and mites may be passed between bees if mingle in
feeders, but normally there is some progressive robbing in all yards
in fall, so I doubt that open feeding is a huge additional concern.
Besides drones go into any hive they like -- within miles.
 
The obvious question is the loss of bees that can be seen
occasionally in the bottom of the drum after all is done.  My
thoughts are that two inches of bees (5 cm) in a drum feeding 12
hives anounts to about a 4 inch ball of bees per hive. That is not a
big loss in the fall.  Besides, I have *never* seen 2 inches of
bees in a drum -- one inch is the most I've seen, and that is rare.
 
Moreover, many argue that the bees lost are old foragers, and are
best removed anyhow for TM control and better wintering.  I'm not
sure of that, but I do know that too big a cluster will use more
stores early in the winter.  There is likely an optimum size range
for economical wintering, and this small loss will not likely reduce
most colonies below that range.
 
What causes this visible loss?  There are two main culprits:
 
-- drowning (and syrup clogging)
-- fighting
 
Drowning is caused by moving the drum when it is full of bees, using
thin syrup, or letting water into the drum -- or by using poor floats.
As mentioned before, wheat straw -- or equivalent -- is the best,
and a wad 3" thick or more should be made up by sprinkling the straw
into the full drum, then patting down gently to make a porous mat.
 
An important note: once straw becomes wet, it is useless.  Thick
syrup does not actually *wet* good straw, but rain will make it
mushy.
 
If the syrup is 67% sugar, the bees cannot drown easily, since they
float and are often not even wet if they fall on it -- due to the
surface tension of thick syrup.  Everyone has seen waterbugs walk on
water; this is a similar effect.  The straw mat allows bees to climb
out if they slip, and also to have a place to stand to approach the
syrup. On the initial trip, they have no idea where exactly the
syrup actually is, and rush madly down into the drum until they
encounter the syrup with some part of their anatomy.  Since it is not
like nectar in a flower, some learning is then involved.
 
Bees that fall into thin syrup or brush against wet straw get coated
with sugar, and depending on the day, may or may not be able to get
groomed enough to fly again.  If not, they will form a mass on the
centre of the float, while the less disabled of them will climb the
walls and walk as far as they can. I prefer HFCS for feeding because
it does not form a dry white scale on the bees like sucrose.
Moreover, it does not get a hard scum on top on dry days.
 
Fighting will ocur if the feeders do not have sufficient surface area
for the number of hives being fed,  Fighting can be observed on
flowers when supply is limited, and feeder drums are no different.
This conflict can result in robbing, stinging incidents, and loss of
bees.
 
The solution is to ensure that more than enough syrup is available to
plug all the hives in the fall, and to have enough surface area on
the feeders. The matter of providing enough syrup is one of the most
subtle factors in the whole system.  We hear that only the strong get
fed using open feeding, however the obvious point that is missed by
detractors is that once a strong hive is full, their bees stop
foraging, and the other hives catch up.
 
I can't over-emphasize how important this is for several reasons:
Firstly, if hives are not full, the bees continue to seek food, and
wear themselves out.  Even if you eventually feed empty hives in late
fall, the bees will be no good since they are worn out from searching
and working meager sources, and early winter losses result. Lack of
ample feed is a severe stress on bees.  That is why it is so
important to fill the hives up as soon as we wish brood rearing to
end in the fall.  For one thing, this buries all pollen under 'honey'
in sealed cells, and preserves it for later when it is needed, and
secondly, the bees become somewhat dormant and preserve their vigour
when there is no room for more honey.
 
Another thing to think about is whether all the hives in the yard
know that food is available.  If some hives are fairly well fed, they
may be semi-dormant, and not notice open feed available.  Usually
scouts from active hives will wake them up by trying to rob, but if
time is short, it is wise to disturb all the hives in the yard when
delivering feed.
 
An interesting observation on open feeding vs. top feeders: This
fall, I had my guys providing supplimentary feed to spits with hive
top feeders, since the splits were a little light and late getting
fed.  The whole yard -- including large hives -- had drums available
too. The splits got one feederful taken down and the boys refilled
them again.
 
When I went out to wrap in the middle of October, the bees in the
splits were clustered down in the bottom (standard) brood chambers,
and the centre frames in the upper (standard) boxes were full and
capped -- but the outer ones were unfinished.  The bees were not
interested in their own full hive top (Miller) feeders at all, but
were rather flying out to the drums and also visiting *neighbouring*
hives to slide under cracks between lid and feeder to steal some
syrup to take home!
 
About Barrel Feeding in the Spring
 
The idea in the fall is to plug the hives, and the way that we
achieve even feeding is by feeding until every hive is heavy.  In
the spring, we do not wish to plug our hives.  This appears to be a
problem, however...
 
In the spring, there is a lot of room in the hives, so the
chances of stopping the queen from laying are slight at first.
Moreover feed consumption is high, so if the queen gets crowded out
by feed, chances are that it will be gone quickly.
 
In the spring, good beekeepers usually try to equalise their hives.
This makes it likely that they will all forage about equally.  Those
that don't are prime candidates for a little work.  Moreover, if
some hives do take more than their share, it is very nice to find
extra feed in them, ready to share with hungry hives while you are
equalizing.
 
I have found that bees do not respond as well to open feeding later
in the spring, as compared to early spring.  A yard (24 hives) will
often take a drum in a warm spell in March (before nectar and
reliable pollen here in Alberta).  We can sometimes feed a drum or
two later, but it depends on the spring, and the bees are weaker by
then.
 
There are many more factors to consider in using drums to feed, but
these are the basics.  Unless one considers all these factors and
manages them wisely, barrel feeding will not seem too good.
 
The Boardman feeder controversy still flares up from time to time,
and although I personally consider them *worse* than useless, I have
to admit that many good beekeepers swear by them and make them work
for them.  It all depends on one's location, goals, and techniques.
What works in one location is a good way to go broke somewhare else.
 
Open feeding is another *expert* technique that when practised with
less than full understanding can lead to disaster -- or
dissatisfaction and puzzlement.  As with all beekeeping techniques,
careful observation and understanding of bees and their constantly
changing ways are essential for success.
 
FWIW