PART II
To All, and to Gavin Ramsey in particular,
7. The authors provide few details, and only one track, about the tracked
bees that presumably did search for attractive odors. But the search is
described as occurring in arcs. This is not at all the way regular recruits
are expected to search for odors, according to v. Frisch's DL hypothesis.
In fact, he took it for granted that whenever recruits, with their presumed
very poor sensitivity to odors, search for attractive odors, they do it by
conducting a circular search that gradually expands around a starting point.
His first study on honeybee-recruitment led him to correctly conclude that
recruits used odor, and NO information about the location of any food. The
details of the results he obtained in that specific study, however, was to
the hive, the earlier it was found by recruits, and the breater number of
new-arrivals it revceived. His error regarding the very poor sensitivity of
honeybees to odors, then, lefthim no choice but to assume that the way
recruits search for attractiveodors, is by conducting a circular search that
gradually expands around the hive, and extends all the way to the limits of
the foraging area. Exactly the same type of expanding circular-search is
retained also in his DL hypothesis, but it starts at the hive, and extends
to the limits of the round dance range, for round dances. It starts at the
point reached by use of distance & direction information contained in
waggle-dances, and extends within a relatively (actually unspecified0 short
range, for waggle-dances. (See "more information" about v. Frisch's
odor-searches.)
8. Both distance-information, and direction information, contained in
waggle-dances for any specific site, have a normal distribution; with the
maxima presumably providing the correct information (at least under light
wind-conditions). His DL hypothesis, therefore, predicts that recruits
should fly out in a fan-formation, with the maximum number flying in the
correct direction, and all the rest deviating to the right, or the left from
the correct direction; the greater the deviation, the smaller the number of
bees that make it. The "fan" is also expected to be wider, the closer the
feeder is to the hive. (This last point need not concern us here, beyond the
fact that the experimental feeder was always kept at a distance of 200 m.
from the hive, i.e. not very far from the hive.)
In addition, among the very many auxiliary hypotheses introduced into the DL
hypothesis, v. Frisch was obliged to assume that recruits contribute errors
of their own (again, the greater the error, the fewer the bees that make
it.) As a result, he claimed that even if recruits found a man-made site
with the foragers' food-odor in exactly the opposite direction to that of
the foragers'-feeder, they still used the distance & direction information
contained in the foragers'-dances; but they used the information with
combined errors of up to 180 degrees. (Well, you can't make a combined error
that is greater than that.)
Riley et al., of course never tracked any bees that flew in the opposite
direction to that of the experimental feeder; and such cases are expected to
be rare anyway. All the samples the authors obtained are, however, far too
small to determine whether the tracks do, or do not show any semblance of
the "fan-formation", expected according to the DL hypothesis.
8.The study also involves a logical contradiction. The authors enlist help
from the studies by Gould (in Science of 1975), and by Srinivasan et al. (in
Science of 2000). I debunked the interpretations of data provided in both
studies. (See "more information", about those 2 studies.) Gould's
interpretations of his data are even totally irrelevant to the whole DL
controversy. Riley et al., however, accepts Gould's interpretations as fully
valid, and Gould claimed to have experimentally confirmed that
honeybee-recruits use DL information only under v. Frisch's conditions.
Under the circumstances Riley et al. should have tested the DL hypothesis
specifically under v. Frisch's conditions. Instead, they did not, and could
not have done that at all.
Why? Because v. Frisch's conditions (as used by Gould), required , among
others, using food with one scent to train the foragers, and switching to
food with a different scent for actual tests on honeybee-recruits. Riley et
al., however, very deliberately EXCLUDED THE USE OF ANY SCENTED FOOD. And,
of course, as I pointed out, HAD THEY USED SCENTED FOOD< THEIR PRESUMABLY
DISCOVERED DL WOULD QUICKLY DISAPPEAR INTO THIN AIR.
Do you still view that radar-tracking study as "science of the highest
quality"? I know, the honeybee DL hypothesis also looks very attractive,
until you take a very careful look at it, and realize what a terribly
incredible mess it really is.
I can, in fact, explain all the results obtained in that study without
recourse to any DL information, had the tracked bees been only re-recruited
trained foragers. I shall, however, skip all the details, because the
precautions the authors describe exclude the possibility that the bees
radar-tracked in this specific study were anything other than regular
recruits (even though the 2 special bees that landed on the feeder-stand
definitely behaved like re-recruited trained foragers, instead of regular
recruits).
For my proposed explanation, which I intend to skip altogether, I need among
others, that the feeder-stand (but not the feeder), be contaminated with
environmental odors. This is a possibility which cannot be excluded at all.
The feeder was often exchanged with a clean, fresh feeder, with new food.
But the stand remained unchanged.
Unlike Wenner, who conducted his studies in an area that turns into a dry
desert in summer, the study by Riley et al., was done in a very large
pasture in Germany. The pasture obviously contained different types of
vegetation, with some food-bearing plants. The pasture was mowed. There was
no fresh vegetation near the hive, or the feeder, and observers could easily
reach both sites, without trampling on any fresh vegetation. The climate in
the area was, however, such that, even though the study was conducted in
summer, the grass that remained attached to the roots after the mowing,
continued to grow. Under such conditions the mowed grass might not have
dried enough to lose all odor-traces for honeybees, with their exceptionally
high sensitivity to odors. Tiny bits and pieces of such mowed grass dust,
light enough to be carried by the wind, could then very easily contaminate
the feeder-stand. It might take a while, and winds blowing from different
directions, to contaminate the feeder. A newly replaced feeder might remain
uncontaminated for a short time.
Now, I know (based on information provided by Greggers), that there were
also un tracked new bees that arrived at the site of the experimental feeder
on their own; which was to be expected, especially during the
foragers'-training, in view of the technique the authors used for that
training (which Greggers also explained to me).The authors state in print
that they never saw any upwind zigzags in the radar tracks. I have not,
however, been able to obtain an answer to my question whether the un-tracked
new bees that arrived at the experimental feeder-site, also arrived without
any upwind zigzag. The 3 British authors would not know the answer, because
they were busy with the radar equipment. The only ones with access to the
information are Menzel, or Greggers, or both. They have so far declined to
respond. Now, get me the answer to this question, and I just might be able
to say something more definite about the possibility that the feeder-stand
was contaminated by odors.
Incidentally, I am not nitpicking at all. I am dealing with a sensational DL
hypothesis, that concerns the very foundations of the whole field of
Behavioral Science, that was STILLBORN, more than 80 years ago, thanks to v.
Frisch's own, first study on honeybee-recruitment (published in an
extensive summary in 1923). Nothing can revive a stillborn hypothesis. And
any new claim of an experimental confirmation of such a hypothesis, must be
very, very carefully examined.
--
Sincerely,
Ruth Rosin ("Prickly pear")
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