Which bird thermals the best?

On Nov 15, 4:59*am, Scott Alexander
wrote:
So in a recent conversation with a greatly experienced soaring pilot,
I was told that Buzzard's have terrible thermaling skills. I tend to
agree with this as it sure seems Buzzards don't get into the core and
stay there. The lesson learned was don't let Turkey Buzzard show you
where the core is, just let them lead you to the thermal.

I thought it would be interesting to ask you good people if anyone has
any knowledge on these issues. *Does anyone know which broad winged
birds have better or worse centering techniques that you can use to
your advantage?

SA

I've been writing some short articles on birds and soaring. I'll
attach some exerpts from one here.

In Arizona and Coloorado the big wing birds I work with most are Red
Tail Hawks. But, when looking for the best cores the little Swifts
are THE best indicators... but you have to look closely to notice
them.

Swifts are a family (Apodidae) of small, highly aerial birds, flying
almost constantly except when at the nest or roosting at night. As
using rising air helps conserve their energy, these little guys are
real pros at working thermals, and they tend to find the best thermals
wherever they fly. They also have impeccable eyesight (about 10X
human eyesight), allowing them to see small insects in the air.
Amongst the fastest flyers in the animal kingdom, the common swift
(Apus apus) can cruise at 12 to 30 mph and is capable of 130 mph for
short bursts. Swifts not only can fly fast, they are incredibly
aerobatic, often changing directions almost instantly, which helps in
their quest for dinner in thermals.

Back when I was flying hang gliders cross-country, we saw them often
(commonly above 16,000’), and when we did, we knew we were in the best
part of one of the best thermals of the day. Sitting under the hang
glider, fully exposed to the elements, I had a “front-row seat” to
watch swifts dart around me in good thermals. It was not unusual to
see them zip in between my wings and flying wires, often within a foot
or so of me. Incredible flying accuracy. Little wonder one of the
première aerobatic gliders is aptly named the SWIFT!

Powerful thermals vacuum insects from the surface and propel them
skyward, and swifts have an uncanny knack for spotting these swirling
aerial food bazaars, utilizing them for high altitude feasting. In
the spring of 2009 I was flying with a friend, Ted Grussing, in his
Lambada motorglider on a good soaring day, and we worked some pretty
nice thermals going to and from the Grand Canyon. It was one of those
days when about ¾ of the clouds were duds, as far as good thermals
were concerned. On the way back, we glided over to the best looking
cloud of the day, and rode the elevator up. Seeing a swift dart by as
I was making the 3rd 360, I immediately turned to core what he was
in. Bingo! Our 12 kt average leaped to 17 kts in the tight core.
Yahoo! Crank & bank! The good looking cloud had attracted us, but
the swifts helped me find the best part of the core. The last we saw
of them was when we were pulling out at 17,500’. Those little guys
obviously aren’t concerned about class A airspace….

Bob T.
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