On Mon, Sep 09, 2002 at 02:47:42PM +1000, R & J Frankenberg wrote:
> But how much does a Rainbow Lorikeet have to eat to get 10 joules?
A joule is one thousandth of a kilojoule, which is the unit used for
energy content in food labelling.
Honey has roughly 10 kilojoules/gram so a milligram (a thousandth of a
gram) of honey will contain 10 joules.
Inefficiencies mean that a lorikeet would only be able to convert
perhaps a quarter of the food energy it consumes into mechanical energy.
The remainder will be converted to heat. A Lorikeet will need ~4
milligrams of honey to produce 10 joules of mechanical energy.
Migrating birds make 4000+ kilometre non-stop journeys on fat reserves
of 40-50% so 100 grams of fat might well be enough fuel for a Rainbow
Lorrikeet to fly Sydney -> Perth.
Andrew
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