John Gamblin wrote:
>
> G'day All,
> It's a glorious day down here today and I've just
> asked this of a fellow BA list member .... but I would
> like to ask all on this list about this one?
>
> On this gorgeous day down here all is well with me but
> my good friend and fellow towable yacht sailor, capt.
> of the Southern Cross, has an ask? on Wednesday last
> when he was out testing some new blind sailing
> gear/equipment in thick, thick fog he had fly past him
> at about 20/25 feet some Cape Barren Geese? honking
> out loud a clear every few wingbeats or so? we have
> both had this happen to us over the years and wonder
> is this their mode of location finding? it was a real
> pea souper of a fog on Wednesday and Tony Harkin the
> SC's capt. says his equipment worked well and he went
> out in the fog for about 2 miles then safely navigated
> back.
>
> Whilst out there, this was hand in front of face stuff
> and it was hard to read the lines in the palm of your
> hand? he puzzled as I do at how birds do fly in very
> thick fog? especially whilst at sea.
>
> It their honking! cawling a type of echo location? if
> they hear their mates then follow that sound?
>
> A good question eh?
>
> Have a good day everyone. Spring comes early eh?
>
> Goes back to lunch with Eggy, Lee, Ruby and Cole. The
> later soon to fly off I think? geeeeez these miners
> grow fast ....... must be the welsh in them with their
> food secombe skills :^D they secombe food here, they
> secombe food there, they secombe food everywhere.
>
> Sorry hehehe
>
> JAG
>
> __________________________________________________
> Do You Yahoo!?
> Get email alerts & NEW webcam video instant messaging with Yahoo!
> Messenger
> http://im.yahoo.com
I think the honking allows the two CBG to keep in contact with each
other rather than direction-finding.
Perhaps they can see a bit better a few feet up? though at 25 feet up it
might not make a difference.
Perhaps they called in hopes of hearing other CBG reply and then homing
in on them.
I'm told that migratory and maybe other birds have tiny bits of
magnetized iron compounds in their heads and they can pick up info from
the earth's magnetic field for no-sight navigation across oceans etc.
This is how homing pigeons do it, and when they get close they can smell
their own loft..
Apparently humans can judge direction by the magnetic method but I
strongly suspect urban ones get too much interference from electricals
etc. Certainly some humans have absolutely NO gift for self-location - I
tend to get lost on low-cloud days in places with dense cover, eg mallee
scrub.
I think you'll get some interesting answers.
Birding-Aus is on the Web at
www.shc.melb.catholic.edu.au/home/birding/index.html
To unsubscribe from this mailing list, send the message
"unsubscribe birding-aus" (no quotes, no Subject line)
to
|
