Why do bees beard?
My November issue of the ABJ arrived a couple of weeks ago and I have recently finished reading it. I was particularly interested in Dewey Caron’s explanation of why bees sometimes hang in clusters around the entrance to the hive. This is a question that turns up regularly on the Facebook pages and it always attracts the same answers — usually from 1/1 hobbyists (one hive, one year’s experience). So I was surprised that a person of Dewey’s experience would have the same opinion.
I am in Western Australia and we do have warm, dry summers which start, officially, on 1 December. Yesterday, 23rd December at 2:08 p.m. our Bureau of Meteorology announced the current temperature of 44.5⁰C (112.1⁰F) where I live, which most of us would regard as being the top end of warm. So I went to my few hives and not a single colony was bearding. One hive was only a nuc split off from one of the others but four are very well populated colonies.
I became involved in commercial beekeeping in 1954 when I worked for Rob Smith on a major honey flow in the Karri forest. He had 460 hives all on one site, and it yielded what was then reckoned to be a world record honey production (written up in the ABJ) of more than 650 lbs. per hive.
At that time we didn’t use queen excluders and we didn’t have any bearding, presumably because the queens tended to lay throughout the 3-box hives in an inverted “V” so there was always room for the foragers to dispose of their harvest to the receivers and to fly away for more.
And we extracted on site every 2 weeks approximately.
Now that excluders are in general use, and with the entrance placed directly into the brood box, on a good nectar flow the immediately available space for the receivers to dump the incoming nectar is rapidly filled, so the foragers can’t pass on their harvest, and hang outside in a “beard” and consume their collection before flying off.
About 35 years ago I made rims containing the entrance with an excluder fitted on top. They were placed on top of the brood box and were successful except that the bees built a lot of burr comb in them, but they did reduce the bearding. Since then I have fitted all my supers with small entrances, covered (between flows) by a shutter, and this allows the foragers to pass their harvest straight into the supers.
Just now, my bees are in a dearth of nectar and the foragers are collecting water. I figure that, at this temperature range, it would be a case of “All hands to the pumps,” or “All wings flapping,” rather than having some outside developing their tans.
Stan Taylor
Western Australia
Dewey responds:
Stan, thanks for your Letter to the Editor regarding my article on bearding in honey bees. You commented that at 44.5 degrees C your 5 colonies were not observed bearding. I would certainly agree that the temperature record certainly was “as being the top end of warm.” As I sought to explain in the article, we commonly observe bearding in populated colonies mid- toward the end of the active foraging day into the evening hours. The bearders are largely foragers exiting their home. We interpret the response as assisting the colony with temperature, humidity and perhaps carbon dioxide control. And it facilitates the ripening of nectar resources in the hive.
I am not sure that I agree with your statement: “… so the foragers can’t pass on their harvest, and hang outside in a ‘beard’ and consume their collection before flying off.” We see bearding even in absence of active foraging and I question whether the foragers would self-consume the nectar in their honey stomach and then fly back to flowers to collect more nectar. Foraging is a feedback loop — if foragers are not promptly off-loaded they are likely to halt further collection and become unemployed foragers.
I do agree somewhat with your “condemnation” of queen excluders. Queen excluders have also been labelled, by some, as honey excluders, an expression illustrating that they can impede the movement of bees in the hive. Incoming crop-filled foragers are downloaded by house bees in areas adjacent to entrances and then the house bees (those workers of “middle age” who have completed nursing activities but not are yet experienced enough to be active foragers) take their full honey stomach to empty cells to start the processing of the nectar. If they must pass through the queen excluder (which after it has been on a hive for awhile becomes highly filled in with comb), it can impede their movement. Colonies with heavy amounts of incoming nectar and/or too little empty comb, and colonies with heavy amounts of burr/brace comb, also impede worker movement and also the circulation of air for temperature/humidity/carbon dioxide control by the colony.
So I would believe a “reason” for why you didn’t see bearding under these “top end of warm” conditions could be:
- You mention it is a hot but not humid region where your colonies were sited.
- You were not using queen excluders.
- You used a rim between brood and supers. Although filled with comb, it is comb the bees built as part of their hive organization — we assume the bees “knew” what they were doing — it was an effective barrier to limit queens moving into supers, but because the bees constructed it they did so as part of their internal hive temperature/humidity control.
- You frequently extracted honey, so (presumably) there was empty comb for processing of incoming nectar. In other words, you were intelligently managing your bees to benefit them under your environmental conditions rather than just “thinking” of yourself as a beekeeper who “knows better” than to just follow advice on how to manage bees written for a different set of environmental conditions.
Dewey
