Date: Sat, 25 Jan 1997 16:53:56 -0500
Reply-To:
Discussion of Bee Biology <BEE-L@CNSIBM.ALBANY.EDU>
Sender:
Discussion of Bee Biology <BEE-L@CNSIBM.ALBANY.EDU>
From:
Excerpts from BEE-L <bees@systronix.net>
Subject:
Open Feeding
> 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 amounts 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 water bugs
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 occur 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 supplementary 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 feeder-ful 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
equalize 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 somewhere else.
Open feeding is another *expert* technique that when
practiced 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 allen |
