Jack and Michael,

I knew that there would be some skeptical people out there! It is
probably much more complicated than high pressure, and low pressure.
Others have also caught my oversimplification. Temperature has a LOT to
do with it, but assuming that the temperature stays the same, I do think
that there is a difference in the amount that the birds need to consume.

First, I suppose I must tell you all where I got my information. There
was a recent thread on one of the falconry lists that I am on, and it
dealt with how the falconers and rehabbers on the list noticed this in
their captive raptors. When there was high pressure, they would hold
their weight for days, and when there was a sudden low pressure front,
they would need more to maintain what falconers refer to as the birds
"flying weight". I made the assumption that this was also probably true
for wild birds.

As for the type of high, or type of low, and any precip that might come
with it, you must remember that temperature is a major factor, and these
birds were also shielded from the elements.

Does this help?


Michael Dossett
Shoreline, Washington
mpdossett at Juno.com


>I need your reference for this one, Michael. I really have a hard time
>believing
>that macro changes in pressure can affect nutritional requirements of
>birds.
>Sense pressure changes, most definitely yes. But as far as affecting
>their diet,
>I am a doubter. Yes, in winter, higher pressures are most often
>associated with
>continental "cold" high pressure areas ("Arctic domes") which you
>coasties got
>a taste of these past few days. I would think that it is much more
>likely that
>the colder temperatures associated with the Arctic outbreaks (and
>associated
>higher pressures) necessitate an increase in nutrient uptake to
>maintain
>metabolic stasis. Temperatures, yes; pressures, no.
>
> - Jack