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Re: surface/volume ratio and water loss in smallest amniotes

Not so consitent, David (wingspan/length):
Birds => 6,5/5 cm for *Mellisuga helenae*, the Bee Hummingbird
Bats => 16/3 cm for *Craseonycteris thonglongyai*, the Kitti's
Hog-nosed Bat or Bumblebee Bat
Pterosaur => 25/7 cm for *Nemicolopterus crypticus* (length estimated
after a composite reconstruction by John Conway).

Note also that:
1. The Bumblebee Bat is one of the main compettitors for the title of
the world's smallest mammal with the longer but lighter - terrestrial
- Etruscan Shrew.
2. The holotype of *Nemicolopterus* may be a juvenile *Sinopterus*
according to Darren Naish (see Tetrapod Zoology).
3. *Nemicolopterus*, if an adult, is quite larger than the others
(especially the wingspan).
4. Be small is not a problem at all for winged insects, so if there is
indeed a relation between flight and lower size limit in amniotes, it
should thus be inherent to the animal (metabolism, physiology,
anatomy, reproduction, ...) rather than to flying weather conditions.

2010/2/10 David Peters <davidpeters@att.net>:
> Speaking of 2/3, 3/4...
> I ran across this article and a few others like it that describe the world's 
> smallest extant amniotes and their desiccation troubles whenever removed from 
> their moist leaf litter environments.
> On a similar note, there seems to be a lower size limit (for adults) for 
> pterosaurs, birds and bats that's pretty consistent even though each has 
> different 'surface' characteristics. Anyone know of any papers along these 
> lines?
> Would the lack of smaller birds/bats/pterosaurs be more of a flight problem 
> (too small for windy conditions or incoming rain drops)?
> Or a water-loss problem?
> Baby bats have smaller wings, but embryo pteros do not, as we know.
> Ref below
> David Peters
> Caribbean Journal of Science, Vol. 37, No. 3-4, 168–173, 2001
> At the Lower Size Limit in Amniote Vertebrates: A New Diminutive
> Lizard from the West Indies

Jocelyn Falconnet