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From:
"Adrian M. Wenner" <[log in to unmask]>
Reply To:
Informed Discussion of Beekeeping Issues and Bee Biology <[log in to unmask]>
Date:
Fri, 10 Mar 2006 16:52:27 -0800
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Dear BEE-L subscribers,

    We have had a lot of exchange about "bee language" on BEE-L this 
past couple of weeks, with some of the postings coming from several 
dedicated bee language advocates (and one newly "converted" advocate).  
  I deeply appreciate their various comments, because it provides yet 
another chance to clarify matters with solid evidence.

    Although several contributors seem enthralled by the radar-tracking 
experiments, I feel that Riley and co-workers failed on a number of 
counts:

1)  They assumed that one can catch a bee after it leaves a dancing bee 
and before it leaves a hive — and then that it might "intend" to go to 
a specific site (an assumption never proved).  They then glued a weight 
onto its back, released it, and expected that bee to behave as if 
nothing had happened — that its "programming would not have been 
altered by the treatment.

2)  They ignored basic tenets about experimental techniques that have 
been with us for 140 years.  For instance, as Claude Bernard (father of 
modern experimental biology) wrote in 1865, " ... when we have put 
forth an idea or a theory in science [ in this case "dance language" ], 
our object must not be to preserve it by seeking everything that may 
support it and setting aside everything that may weaken it."  (More on 
that below)

3)  Their experiment lacked adequate controls.  For instance, they did 
not radar-track bees that had attended dancers that had "indicated" a 
different direction than the one they anticipated.  Nor did they track 
bees that left the hive but had not attended dancers.

4)  They erroneously presumed that their conclusion (that bees had 
"used" direction information obtained from dancers) was the only 
interpretation that could be reached from their results.

    The most egregious of the above, perhaps, is that they "set aside 
all evidence that might weaken" their mind set.  That is, they tried 
mightily to prove the bee language hypothesis true instead of putting 
it to a real test (e.g., blind, double blind, etc.).

    (Please note that I do not dispute that the couple dozen tracked 
bees that they reported upon all went off in the same direction.)

    In response, I present here some of the evidence that language 
advocates consistently ignore (as indicated in point 2, above), 
evidence that comes from only one of our many publications on the 
matter.  (No, you will not find this evidence summarized in any 
publication written by bee language advocates — for obvious reasons, as 
listed in point #2, above.)

    The evidence as summarized below appeared in the journal SCIENCE, 
after thorough pre-publication review by anonymous referees.   That 
paper can be found at:

http://www.beesource.com/pov/wenner/sci1969.htm

    In those experiments (as in others) we employed rigorous controls, 
as well as blind and double blind techniques.  Neither organizers nor 
participants knew what results to expect.  All test stations were 
cleaned and fresh glassware with new sugar solution set up each 15 
minutes.  Dirty glassware was placed in sealed plastic bags.  Data 
gatherers at each station had no contact with others during the full 
three hour period each day.  Marked bees regularly flew between hive 
and feeding stations.  Arriving unmarked recruits were gently picked up 
and dropped into bottles of alcohol for later tallying.  We did not try 
to prove any hypothesis true but strove to learn what cues recruits use 
when they search in the field for food sources visited by regular 
foragers.  (We had already learned from earlier experiments that 
recruits end up at a set of scented stations according to their 
geometrical placement in the field — rather than in a distribution 
predicted by the language hypothesis.)

    Here are the results from two of the sets of experiments:

SET  #1)  In that 1969 SCIENCE paper we concluded in part:  "That bees 
locate a food source by olfaction is especially possible in view of the 
extremely low recruitment rate of regular foragers collecting unscented 
sucrose at an unscented site.  On 25 July 1968, for instance, in the 
absence of a major nectar source for the colony, we received only five 
recruits from a hive of approximately 60,000 bees after ten bees had 
foraged at each of four stations for a total of 1374 round trips during 
a 3-hour period."  (That averages out as 0.0036 recruits per forager 
bee round trip at unscented food during a period of scarce natural 
forage.)

    We knew from other earlier experiments that:  a)  the less odor in 
the food, the more frequently foragers dance in the hive and b)  
foragers expose their Nasanov glands most often at unscented feeding 
stations in the field.  In other words, searching recruits in our 
experiment did not find the target stations, despite the fact that 
foragers danced more often than ever in the hive and exposed their 
Nasanov glands nearly every time they fed at the dishes.  There was 
thus nearly always a distinctive odor at the feeding stations (N.G. 
gland odor) — but not an odor that recruits had associated with the 
sugar solution reward before leaving their hive.

    In the summer of 2003 I demonstrated that same result to a group of 
military and civilian observers in Maryland.  We had about 40 colonies 
of bees feeding on unscented sugar solution at various test stations.  
Each test station had a scent (odor of an explosive chemical) 
associated with but separate from the sugar solution.  Recruitment was 
very high at all such test stations.  At another location I set up a 
dish of unscented solution but with no associated scent.  During a 
3-hour period, no searching bees landed at that unscented station.

    In December of 2005 a film crew came here to Santa Barbara from 
France to get footage for a film on "animal language," choosing me as 
the focus for bee communication.  I demonstrated how to train honey 
bees to visit food sources.  In addition, I set out a dish of unscented 
sugar solution and had them train a camera on that dish.  Even though 
foragers collected unscented food for a full two days from dishes with 
a scent associated with the reward — and recruits regularly showed up 
at those scented dishes — no bees arrived at the dish with unscented 
solution that lacked the appropriate associated scent.

    I feel very confident that I can demonstrate this failure of bees to 
find unscented sugar solution at any time and in any place — given very 
tight controls on how the sugar solution is prepared.

SET #2)  Consider the results of a more extensive set of experiments as 
reported in that 1969 paper.

    During the summer in Santa Barbara we have remarkably uniform 
weather.  That condition permitted us to run an uninterrupted series of 
recruitment experiments for 24 consecutive days.  One can see ALL the 
results we obtained in Table 1 of that paper (see URL, above).  A 
synopsis follows.

   Ten marked bees regularly visited each of two stations at 200 m from 
their hive and 280 m from each other.  On some days we used unscented 
sugar solution; on other days we used scented solution.  Each trip by 
each bee was tallied, as was the number of unmarked recruits captured 
and the number of times marked foragers exposed their Nasanov gland.

RESULTS:  A)  Only 86 recruits arrived during a total of 18 hours (on 
six days) at dishes that had unscented food.  During those hours, 10 
foragers made repeated regular trips to each dish and exposed their 
Nasanov glands 2,187 times.

B)  By contrast, 1,717 recruits arrived during a total of 33 hours (on 
11 days) at dishes that had scented food, with foragers exposing their 
Nasanov glands 2,096 times.

SUMMARY:

    Recruits per hour to unscented food — 5;  N.G. exposure at the 
station, 243 per hour
    Recruits per hour to scented food — 156;  N.G. exposure at the 
station, 127 per hour

    Those results were obtained in an experiment with an A PRIORI 
"crucial experiment" design (not the weaker A POSTERIORI interpretation 
by Gavin Ramsey about the radar-tracking study).  To continue, on some 
days of the 24-day sequence, we switched the two target stations to 
unscented solution, set up a test station between the two of them, and 
provided scented solution at that third station instead.  (Regular 
foragers continued to fly and collect unscented solution from stations 
at which they had been trained, but no such foragers ever landed on the 
third, test station.)  On those test days, recruits that left the hive 
could either use direction and distance information obtained from a 
dancing bee, as expected by the language hypothesis, OR they could 
search for the odor of the food that had been brought into the hive the 
previous day.

    That is what one means by a true "crucial experiment" (or "strong 
inference" experiment).  The searching bees could either go to where 
they had supposedly been directed by the dance maneuver (to one of the 
two stations visited by foragers) or they could search for the food 
odor (at a third station never frequented by foragers) — a mutually 
exclusive set of outcomes.

RESULTS:  Consider here the results from 8 of those days of the 
experiment — four days in which recruits arrived at stations with 
regular foragers feeding on scented stations and four days of recruits 
arriving the day immediately after, when foragers fed on unscented 
food.

A)  When foragers fed on scented food, a total of 666 recruits arrived 
on those four days.  The Nasanov gland was exposed only 721 times.

B)  When foragers fed upon unscented food on subsequent days, a total 
of only 33 recruits arrived at the two stations visited by forager 
bees.  However, 224 recruits arrived at the third test station instead, 
which had the scented food used on the previous day — though no 
foragers ever fed from that intermediate station.

    That low turnout of recruits (33) at the two stations visited by 
regular foragers that collected unscented sucrose solution occurred 
despite the fact that, collectively, foragers exposed their Nasanov 
glands 1,218 times.

SUMMARY:  Recruits should have arrived primarily at the two stations 
where bees visited unscented solution IF they had used dance maneuver 
information.  Instead, 87% of the recruits arrived at the single test 
station that had no foragers but had the scented food used the day 
before.

[NOTE:  In 1946 von Frisch published some similar results, results that 
revealed that Nasanov gland scent failed to attract recruits.  He 
dismissed the disconnect between his results and his earlier hypothesis 
that it did so, as follows: " ... there is no doubt about the existence 
of an attraction exerted by the scent organ ... which has also been 
confirmed in further experiments into which I do not want to go here... 
"  One can find a complete coverage of the Nasanov gland hypothesis 
problem in Excursus NG of our 1990 Columbia University Press book at:

http://www.beesource.com/pov/wenner/EXC_NG.htm

    Did our crucial experiment ever get repeated?  Yes, but only in 
part.  That is a very interesting story in itself.   The powers that be 
were apparently deeply disturbed by the rigorous nature of our 
experimental design and by its implications.  Unbeknownst to us, those 
powers (apparently including E.O. Wilson) arranged for Martin Lindauer 
from Germany to come to Woods Hole Oceanographic Institute in the 
following summer to repeat our experiments there, presumably to 
determine what we had done wrong.  (As one might normally expect out of 
professional courtesy, they did not invite any of us to participate.)

    Lindauer obtained much the same set of results that we had obtained, 
though he apparently could not bring himself to use unscented food at 
the two regular feeding stations.  Recruits still arrived 
preferentially at the central station when odor was provided there on a 
subsequent day.  Did that shake his (or others) faith in the language 
hypothesis?  Not at all.  Instead, Lindauer concluded (without 
observation) that recruits must have paid attention to dance maneuver 
information from dancers that visited both outside stations, averaged 
the directional information, and flown out to the central test station. 
  He thus ascribed even more capability to bees than earlier claimed (an 
ability to average directional information).  In doing so, he ignored 
the fact that recruits failed to arrive in larger numbers at the two 
outside stations than at the central station — even though Nasanov 
gland exposure by regular foragers would have been high there and 
absent at the central station not visited by foragers.

    Anyone can repeat the above experiments in a few weeks in late 
summer during a nectar dearth.  All one has to do is to be willing to 
accept the results obtained and not dismiss results that may not match 
prior expectations.

RADAR TRACKING STUDIES

    It would appear that some people think the radar tracking study is 
on a par with or superior to the studies we have done earlier.  
However, I fail to see how the radar tracking study can in any way 
compare with results obtained in the above comprehensive study and 
others we have done.  Just because radar tracking involved a high-tech 
approach does not mean the experiment has a more rigorous design.  The 
opposite is, in fact, true — as explained in my introductory comments 
above.

    As for me, I am going to stick by my guns.  I trust results of the 
natural behavior of thousands of unmolested bees obtained by use of 
blind, double controlled, and true crucial experiments more than 
interpretation of results obtained from the behavior of a couple dozen 
bees by someone else who tries to prove a favored hypothesis true.  The 
two types of experiments are not on a par with one another.  Neither 
should a believer in bee language be willing to discard evidence 
obtained about the behavior of thousands of unmolested searching bees.

    Neither is all this controversy about a perceived unwillingness on 
my part to change my mind if compelling counter evidence comes in.  One 
cannot erase from Nature the documentation we have published about the 
behavior of searching bees.

    Nor is it all about what I, personally, might WANT bees to do, it's 
about how bees really behave.  That's one of the reasons I recently 
published the review paper found at:

http://www.beesource.com/pov/wenner/jib2002.htm

    This continuing saga reminds me of a statement by Nobel Laurate 
Peter Medawar:  "It is a common failing — and one that I have myself 
suffered from — to fall in love with a hypothesis and to be unwilling 
to take no for an answer.  A love affair with a pet hypothesis can 
waste years of precious time.  There is very often no finally decisive 
yes, though quite often there can be a decisive no."

    Have we wasted enough time and resources on this controversy yet?

												Adrian

Adrian M. Wenner		(805) 963-8508 (home office phone)
967 Garcia Road			[log in to unmask]
Santa Barbara, CA  93103	www.beesource.com/pov/wenner/index.htm

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“The more persuasive the evidence against a belief,
the more virtuous it is deemed to persist in it.”

			Robert Park — 2000 (Voodoo Science)

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