Circling for rodents?

Does anyone have an idea of how the birds know where to thermal? Do
they have a vario? Where is it? Where is its capacity?
Assuming they breath while thermalling, then I doubt they use their
lungs as capacity... or maybe they stop and sense the air coming out
their noses.
Just wondering...

Uri 4XGJC

(Andy Durbin) wrote in message
. com...
"Bill Daniels" wrote in message news:aa4Fc.11095$7t3.8707@attbi_s51...

Most hawks circling low are looking for rodents, not lift.

Bill Daniels


But many times I have shared thermals with Hawks at high altitude.
How did they get there if not by working thermals at low altitude? I
have never been in a thermal with a Red Tailed Hawk that didn't seem
to be trying to optimize climb rate. Turkey Vultures are a different
story. They seem to be happy with any sloppy thermal technique as
long as they maintain altitude.


Andy

did you ever feel the aileron twitch.. and instinctively know that the
thermal was to your left or right? with most soaring birds (raptors).. those
fingertip feathers tend to move freely.. sensing every movement of the air..
watch one some time..

as for locating thermals?? some believe they can "see the heat".. ever watch
heat rise of pavement.. that "shimmering" as the heat rises.. perhaps our
raptor friends have better vision than we give them credit for

BT


"Uri Saovray" wrote in message
m...
Does anyone have an idea of how the birds know where to thermal? Do
they have a vario? Where is it? Where is its capacity?
Assuming they breath while thermalling, then I doubt they use their
lungs as capacity... or maybe they stop and sense the air coming out
their noses.
Just wondering...

Uri 4XGJC

(Andy Durbin) wrote in message
. com...
"Bill Daniels" wrote in message
news:aa4Fc.11095$7t3.8707@attbi_s51...

Most hawks circling low are looking for rodents, not lift.

Bill Daniels


But many times I have shared thermals with Hawks at high altitude.
How did they get there if not by working thermals at low altitude? I
have never been in a thermal with a Red Tailed Hawk that didn't seem
to be trying to optimize climb rate. Turkey Vultures are a different
story. They seem to be happy with any sloppy thermal technique as
long as they maintain altitude.


Andy

Hi,

Does anyone have an idea of how the birds know where to thermal? Do
they have a vario? Where is it?

How about simple inertia?

They may sense the vertical acceleration. Humans do so too,
but they cannot integrate the information well over time. Varios
fix that fault just like attitude indicators fix the problem of
spatial orientation.

birds propably have evolved to work more exactly in this aspect.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn.
Fon +49 228 624013, Fax +49 228 624031.
http://www.marian-aldenhoevel.de
"Wie trennt man drei Schlampen von zwei Säufern? Cockpittüre zu!"

Darwin would say the ones that didn't thermal too well didn't
survive, didn't reproduce, and simply missed out on some good
airtime for generations to follow. The birds that acquired the
insight to locate updrafts gained the same advantage we seek: xc
distance. Soaring birds are usually larger than others, maybe good
thermaling skills means better meals. They still need to survive
winters with fewer, weaker thermals by other means.

gill
www.gillcouto.com


Uri Saovray wrote:
Does anyone have an idea of how the birds know where to thermal? Do
they have a vario? Where is it? Where is its capacity?
Assuming they breath while thermalling, then I doubt they use their
lungs as capacity... or maybe they stop and sense the air coming out
their noses.
Just wondering...

Uri 4XGJC

In article , Uri Saovray
writes
Does anyone have an idea of how the birds know where to thermal? Do
they have a vario? Where is it? Where is its capacity?
Assuming they breath while thermalling, then I doubt they use their
lungs as capacity... or maybe they stop and sense the air coming out
their noses.
Just wondering...

Uri 4XGJC

Its a long time since I did any comparative anatomy, but I believe many
birds have air filled cavities in some of their bones.

While on the subject of birds using thermals, the German expedition to
the Andes (1937) decided to bring some raptors birds back to Germany,
the idea being they would find thermals for them. During the voyage back
they were of course kept in cages and fed by the crew. And everyone
else.

When the ship docked in Bremen, the birds had got so heavy they couldn't
get airborne.

From a biography of Hanna Reich.
--
Mike Lindsay