I am terrible at arithmetic but with available simple aids I gather that the distance of the horizon at 30 000 feet is 375km. Assuming the top of distant clouds at a similar height they would be visible at 750km. It is reasonable to assume pelicans rely on other things such as the flight pattern of other (distant) pelicans so there could be a chain of information relayed between points separated by hundreds of kilometres.
-----Original Message-----
From: Philip Veerman
Sent: Sunday, 4 August 2013 9:52 PM
To: 'Elizabeth Compston'; 'Birds Canberra'
Subject: [canberrabirds] birds--pelicans
Apart from that 30,000 feet was intended. Whether you are a pelican (not likely), pilot or passenger at 30,000 feet near Sydney, I'm sure you cannot see central Australia nor clouds over it. I'm no frequent flyer but I love looking out the window when I do. Assuming a fairly flat landscape I don't know but I'd surprised if from a normal interstate plane you could see the land surface much more than 100 km away.
The question is that many birds seem to be able to time their arrivals at rare and irregular inland waters from places far away. Presumably they detect something as a sign of these conditions.
Philip
-----Original Message-----
From: Elizabeth Compston [m("grapevine.net.au","elizabethcompston");">]
Sent: Friday, 2 August 2013 8:14 PM
To: Birds Canberra
Subject: [canberrabirds] birds--pelicans
I wrote a message yesterday to the pilot of a QANTAS plane that I was on,
telling him that it had been reported that pelicans can fly as high as
300,000 feet, and asking him. If you were at a height of 30,000 feet near
Sydney, would you be able to see rain falling in central Australia. He
reputed the idea that pelicans fly that high. So, where did the information
come from, about the height that pelicans can fly? and is it a myth?
Elizabeth
****************************************************************************
***************************
*******************************************************************************************************
This is the email announcement and discussion list of the Canberra Ornithologists Group.
Please ensure that emails posted to the list are less than 100 kB in size.
When subscribing or unsubscribing, please insert the word 'Subscribe' or 'Unsubscribe', as applicable, in the email's subject line.
List-Post: <m("canberrabirds.org.au","canberrabirds");">>
List-Help: <m("canberrabirds.org.au","canberrabirds-help");">>
List-Unsubscribe: <m("canberrabirds.org.au","canberrabirds-unsubscribe");">>
List-Subscribe: <m("canberrabirds.org.au","canberrabirds-subscribe");">>
List archive: <http://bioacoustics.cse.unsw.edu.au/archives/html/canberrabirds>
List manager: David McDonald, email <m("canberrabirds.org.au","coglists-owner");">>
