I watched a Muscovy duck as it climbed a tree*, bipedal while flapping it's wings. Seems like that may have been done by proto-birds with strong but short wings not yet capable of powered flight.

Tree stem was not quite vertical but more so than diagonal, the branches were offset and did not interfere with the duck's path.

On 3/18/22 5:54 PM, Daud Deden wrote:
> I watched a Muscovy duck as it climbed a tree*, bipedal while flapping it's wings. Seems like that may have been done by proto-birds with strong but short wings not yet capable of powered flight.
>
> Tree stem was not quite vertical but more so than diagonal, the branches were offset and did not interfere with the duck's path.

Congratulations: you have discovered WAIR (wing-assisted incline
running). See Dial K. 2003. Wing-assisted incline running and the
evolution of flight. Science 299:402-404.

https://www.researchgate.net/publication/10947063_Wing-Assisted_Incline_Running_and_the_Evolution_of_Flight#fullTextFileContent

On Saturday, March 19, 2022 at 12:23:52 AM UTC-4, John Harshman wrote:
> On 3/18/22 5:54 PM, Daud Deden wrote:
> > I watched a Muscovy duck as it climbed a tree*, bipedal while flapping it's wings. Seems like that may have been done by proto-birds with strong but short wings not yet capable of powered flight.
> >
> > Tree stem was not quite vertical but more so than diagonal, the branches were offset and did not interfere with the duck's path.
> Congratulations: you have discovered WAIR (wing-assisted incline
> running). See Dial K. 2003. Wing-assisted incline running and the
> evolution of flight. Science 299:402-404.
>
> https://www.researchgate.net/publication/10947063_Wing-Assisted_Incline_Running_and_the_Evolution_of_Flight#fullTextFileContent
- A bit slow for running, but perhaps mechanically the same as running.
I'd favor WAIR over flat ground running & flapping to produce flight, which I view as very unlikely.
Combining WAIR with compressional perching (needed to be well-feathered in lateral winds) and arboreal pouncing on terrestrial/aquatic prey seems most likely to me as the origin of powered flight of proto-birds.

On Saturday, March 19, 2022 at 12:23:52 AM UTC-4, John Harshman wrote:
> On 3/18/22 5:54 PM, Daud Deden wrote:
> > I watched a Muscovy duck as it climbed a tree*, bipedal while flapping it's wings. Seems like that may have been done by proto-birds with strong but short wings not yet capable of powered flight.
> >
> > Tree stem was not quite vertical but more so than diagonal, the branches were offset and did not interfere with the duck's path.
> Congratulations: you have discovered WAIR (wing-assisted incline
> running). See Dial K. 2003. Wing-assisted incline running and the
> evolution of flight. Science 299:402-404.
>
> https://www.researchgate.net/publication/10947063_Wing-Assisted_Incline_Running_and_the_Evolution_of_Flight#fullTextFileContent

The duck probably moved slower than a partridge due to heavier weight. The tree bark was very rough. I'd seen smaller birds (not Tweety birds) climb this way, I thought it was used mostly only during moulting.Thanks for the cite.

On 3/19/22 4:38 AM, Daud Deden wrote:
> On Saturday, March 19, 2022 at 12:23:52 AM UTC-4, John Harshman wrote:
>> On 3/18/22 5:54 PM, Daud Deden wrote:
>>> I watched a Muscovy duck as it climbed a tree*, bipedal while flapping it's wings. Seems like that may have been done by proto-birds with strong but short wings not yet capable of powered flight.
>>>
>>> Tree stem was not quite vertical but more so than diagonal, the branches were offset and did not interfere with the duck's path.
>> Congratulations: you have discovered WAIR (wing-assisted incline
>> running). See Dial K. 2003. Wing-assisted incline running and the
>> evolution of flight. Science 299:402-404.
>>
>> https://www.researchgate.net/publication/10947063_Wing-Assisted_Incline_Running_and_the_Evolution_of_Flight#fullTextFileContent
>
> The duck probably moved slower than a partridge due to heavier weight. The tree bark was very rough. I'd seen smaller birds (not Tweety birds) climb this way, I thought it was used mostly only during moulting.Thanks for the cite.

If you look up Ken Dial, there are several movies of experiments with
WAIR in various species.

On 3/19/22 7:06 AM,
John Harshman wrote:
> On 3/19/22 4:38 AM, Daud Deden wrote:
>> On Saturday, March 19, 2022 at 12:23:52 AM UTC-4, John Harshman wrote:
>>> On 3/18/22 5:54 PM, Daud Deden wrote:
>>>> I watched a Muscovy duck as it climbed a tree*, bipedal while
>>>> flapping it's wings. Seems like that may have been done by
>>>> proto-birds with strong but short wings not yet capable of powered
>>>> flight.
>>>>
>>>> Tree stem was not quite vertical but more so than diagonal, the
>>>> branches were offset and did not interfere with the duck's path.
>>> Congratulations: you have discovered WAIR (wing-assisted incline
>>> running). See Dial K. 2003. Wing-assisted incline running and the
>>> evolution of flight. Science 299:402-404.
>>>
>>>
https://www.researchgate.net/publication/10947063_Wing-Assisted_Incline_Running_and_the_Evolution_of_Flight#fullTextFileContent

>>>
>>
>> The duck probably moved slower than a partridge due to heavier weight.
>> The tree bark was very rough. I'd seen smaller birds (not Tweety
>> birds) climb this way, I thought it was used mostly only during
>> moulting.Thanks for the cite.
>
> If you look up Ken Dial, there are several movies of experiments with
> WAIR in various species.

So double checking. Can bats stand upright when not flying or can they
only hang upside down? Can some bats do this but not others? I have
looked at a few videos on the subject and it seems to me that bats are
much different from birds.

Pterosaurs could not stand upright when not flying, they could only
walk on four limbs? Could some pterosaurs walk on two limbs? One thing
that I noticed when it comes to bats is that there are muscles inside
the bat's membrane, possibly changing its stiffness properties during
parts of a wing beat. If bats are different from birds then it seems
possible that pterosaurs might have been different from both in some
not obvious ways.

Do flying frogs predate pterosaurs? Do any flying amphibians predate
pterosaurs?

Do flying fish of any type predate pterosaurs? Could there have
been hundreds of millions of years where fish regularly flew over
the ocean both to escape predators underneath as well as to hunt
from the skies, only dropping down periodically to hydrate their
fins or to breed? Was this the situation throughout even half
of the paleozoic and we are misinterpreting the fossil record of
these earlier flying animals?

What would have been the first flying animal? Flying arthropods,
flying fish, or something else?