[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: surface/volume ratio and water loss in smallest amniotes
There is a lot of factors to consider when looking at this problem, none of
which are overwhelming:
1) Total water budget of the ptero (can be easily estimated from its volume and
then modeling either a lizard metabolism vs. a bird metabolism.
2) Surface area of the animal.
3) Stress load on the animal (water loss increases with greater physical
stress.......model this with both a lizard's load and a bird's load).
4) Permeability of ptero integument (model various types...this part should be
5) Flying with the air current vs. flying against the air current (see #3
6) Velocity of the air over the body (this varies between curved surfaces and
flattened surfaces).....best to model this on a computer.
7) Relative humidity (best to just use estimated average RH).
It is amazing that tiny invertebrate flappers can fly against the wind, but
many do. NOVA recently had a show on the migration of the Monarch butterfly.
Truely amazing animals.
I wouldn't be surprised if theory (and experiment) suggests that there is no
absolute boundary for the size/volume ratio of vertebrates, nor of the absolute
minimum size of a vertebrate.
---------- Original Message ----------
From: "Richard W. Travsky" <email@example.com>
Subject: Re: surface/volume ratio and water loss in smallest amniotes
Date: Wed, 10 Feb 2010 21:19:06 -0700
On Wed, 10 Feb 2010, David Peters wrote:
> Speaking of 2/3, 3/4... [...]
> Would the lack of smaller birds/bats/pterosaurs be more of a flight
> problem (too small for windy conditions or incoming rain drops)?
Out in the open seems likely.
If flying is done in forested areas then wind effects could/would
be mitigated somewhat.
Small Business Tools
Free info for small business owners. Click here to find great products geared
for your business.