In message <[log in to unmask]>, Gard Otis
<[log in to unmask]> writes
>Dave,
>    I would not conclude that cerana and mellifera are the same with
>respect to this behaviour and "Ruttner is not right".
 
>If you watch mellifera, you will see the
>vast majority of them facing head into the hive.  And if you look at
>cerana or koschevnikovi, you will see the opposite.  There IS A
>DIFFERENCE, statistically.
 
I'm so glad you said that. Then the fun remains, why is there a
difference ?
 
>Perhaps one could create specific hive environments
>that would cause the bees (mellifera) to fan in in some situations,
>and out in others, and with a mixed strategy in yet others, and that
>would shed light on the question.  Whether that would help to answer
>the difference between mellifera and Asian species (since climates
>they evolved in are rather different) is uncertain.
 
Ventilation, whether this or in over-wintering, seems to have had very
little attention focused on it.
I don't really appreciate how the climates are different although of
course they are. (Presumably the 'climate' inside the hives are the
same?) Earlier you asked if I thought one method would be more efficient
than the other and I said don't know but would assume both to be equally
efficient since they are trying to achieve an optimum. Maybe there is
another reason they face out? The story I heard was that A.cerana did
this so it could keep a better eye out for predators approaching, but as
cerana doesn't seem more defensive (isn't it more docile?) I don't
believe that one either.
--
Dave Black
<http://www.guildford.ac.uk/beehive>,
Guildford, GU1 4RN.  UK.