Syd:
Thanks for the idea - birds with web feet certainly do use their feet
as air breaks and stablizers. Have you ever watched storm petrels using
their feet as anchors as they hover inches above the water's surface?
Cheers, Jim
Dr. Wm. James Davis
e-mail
On Fri, 16 Jan 1998, Syd Curtis wrote:
> On 16 January, Jim Davis wrote
>
> >I am writing an article on flight styles in birds. One particular
> >technique that birds use to minimize effort in flying is to ride the
> >upward air currents (actually a wave) that form on the downwind side of a
> >hill or island. There are published examples of seabirds wave-soaring,
> >but I would like to know if anyone has seen birds in central Australia
> >ride the leeward waves formed behind Ayers rock (Uluru) in Alice Springs.
> >If so, want species and any information what they were doing - hunting,
> >returning to a roost, etc.
> >
>
> I can't help Jim with his Uluru enquiry, but I would like to express a hope
> that in his article he covers the matter of birds using their feet in
> flying. I'm curious to know how widespread this is after noting that on
> Lord Howe Island both Red-tailed Tropicbirds and Sooty Terns do so.
>
> In normal forward soaring flight both seem to tuck their feet in behind
> them. But when a tropicbird goes into aerobatic display it fully extends
> its webbed feet and uses them as rudders and air brakes. The effect of
> seeing this black 'undercarriage' suddenly appear on a snowy white bird, is
> quite startling at first sight.
>
> The Sooties are something else again! Like many LHI birds they seem more
> curious than wary where human observers are concerned. And Sooties love to
> ride air currents, especially if they can get a situation where a wind is
> blowing over a ridge top or the top of a cliff and they can ride it just
> altering their wing angle and occasionally 'pedalling' like mad with their
> webbed feet (also black) so as to remain in the same place relative to the
> ground. To have a Sooty 'holding' like that and peering into one's face
> from about a metre away, is one of the many simple pleasures offered by
> Lord Howe Island.
>
> So. Do other sea-birds with webbed feet also use their feet in flying?
>
> Cheers.
>
> Syd Curtis
>
> H Syd Curtis
>
>
>
>
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