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FW: The ground-nowhere hypothesis on the origin of bird flight (joke)



 <350505.93736.qm@web63803.mail.re1.yahoo.com>
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The birds I mentioned do pounce from trees. Sure. Their hunting
range has greatly expanded because of their highly evolved modern
capabilities. They can also fly after their prey.
=20
Any proavis as you would point out would have a fraction of that=20
range but doesn't make it any less viable. Predators like to stick
around where the prey collects particularly if their range is restricted. W=
aterhole anyone?? --dale (not a joke)

----------------------------------------
> Date: Mon=2C 12 Oct 2009 10:12:42 -0700
> From: erikboehm07@yahoo.com
> Subject: Re: FW: The ground-nowhere hypothesis on the origin of bird flig=
ht (joke)
> To: dinosaur@usc.edu=3B wdm1949@hotmail.com
>
> The birds you mention do not pounce from a tree.
>
> They sit in an elevated position=2C on the lookout.
> The tree serves as a lookout tower=2C from which they can see prey easier=
.
> Once they spot the prey=2C they go chase after it.
> In a humans case=2C once the prey is spotted=2C a projectile is launched =
at it.
> Raptors sitting in a tree will attack prey much farther away than what th=
ey could get to by gliding (especially if that glide has to be fast to catc=
h the prey unaware/in time).
> Like a human in a tree=2C a raptor sitting in a tree has a huge hunting a=
rea.
> Some primitive glider incapable of powered flight sitting in a tree would=
 have a tiny hunting area.
> Several orders of magnitude less in fact.
> At half the "predation radius" (the radius from the perch at which prey c=
an be hunted from the perch)=2C the hunting area is reduced to 1/4.
>
> The early "bird's" glide ratio was clearly less than half that of a hawk/=
eagle/buzzard=2C and the inability to undergo powered flight (since we are =
hypothesizing a precursor to powered flight)=2C lead me to guess the radius=
 from the perch it could go after prey is less than 1/4 that of the radius =
for a raptor.
>
> Thus their hunting area would be less than 1/16th that of modern raptors=
=2C and we can't conclude that because its a viable strategy for modern rap=
tors=2C that it was a viable transition form.
>
> --- On Mon=2C 10/12/09=2C dale mcinnes wrote:
>
>> From: dale mcinnes=20
>> Subject: FW: The ground-nowhere hypothesis on the origin of bird flight =
(joke)
>> To: "DML"=20
>> Date: Monday=2C October 12=2C 2009=2C 9:21 AM
>>
>> <140054.33837.qm@web50812.mail.re2.yahoo.com>
>> Content-Type: text/plain=3B charset=3D"iso-8859-1"
>> Content-Transfer-Encoding: quoted-printable
>> MIME-Version: 1.0
>>
>>
>> Whooooa.
>> =3D20
>> Mammals need to eat way too often to be able to just sit in
>> a tree=3D20
>> and wait for something to walk underneath them? Really??
>> This may
>> not be the preferred method of mammals but they can do it.
>> They
>> don't just pick any old tree. They pick a tree that's
>> reasonably
>> secure for them to sleep in=3D2C drag food up=3D2C and in the
>> case of=3D20
>> hunting=3D2C pick a nice shady spot around a waterhole and
>> wait. Yes.
>> Wait. All day if necessary. If not longer. Burns fewer
>> calories.=3D20
>> Much fewer calories. And meat is reasonably assured here.
>> =3D20
>> But raptors do this. Especially eagles. Hunting fish.
>> Hunting birds.
>> Hunting mammals. Doesn't matter. It probably all leads back
>> to that
>> proavis hunting strategy around a water hole. Think Archie.
>> Am I
>> close here? --dale
>>
>>
>> ----------------------------------------
>>> Date: Mon=3D2C 12 Oct 2009 07:29:29 -0700
>>> From: d_ohmes@yahoo.com
>>> To: dinosaur@usc.edu
>>> Subject: Re: FW: The ground-nowhere hypothesis on the
>> origin of bird flig=3D
>> ht (joke)
>>>
>>> Hmmm. Perhaps the drop-bear is attracted to camera
>> straps?
>>>
>>> More seriously -- mammals need to eat way too often to
>> be able to just si=3D
>> t in a tree and wait for something to happen to walk
>> underneath them. There=3D
>> is another factor too=3D3B most prey is alert enough that
>> missing your initi=3D
>> al pounce is likely=3D2C and if a prey species are slow
>> movers=3D2C then active=3D
>> ly searching works better than waiting anyway. All in
>> all=3D2C I think pounci=3D
>> ng is highly over-rated=3D2C at least in today's world.
>>>
>>> The local anoles seem to use it w/ success on
>> insects=3D2C though=3D2C so I t=3D
>> hink it still plays in flight evolution cartoons.
>>>
>>> Humans hunt deer from trees of course=3D2C w/ good
>> success=3D2C but use proje=3D
>> ctile weapons to greatly increase their killing range as
>> well as various ba=3D
>> its=3D2C scents=3D2C and calls. I once calculated the cost of
>> licensing=3D2C spec=3D
>> ial clothes=3D2C weapons=3D2C trucks=3D2C refrigeration and other
>> accessories and=3D
>> came up w/ a total cost 250$US/lb for venison (although
>> assuming 2 deer/ye=3D
>> ar for 10 years=3D2C and 10 years per truck it gets closer to
>> 15$US).
>>>
>>> --- On Mon=3D2C 10/12/09=3D2C Tim Williams wrote:
>>>
>>>> From: Tim Williams=3D20
>>>> Subject: Re: FW: The ground-nowhere hypothesis on
>> the origin of bird fli=3D
>> ght (joke)
>>>> To: dinosaur@usc.edu
>>>> Date: Monday=3D2C October 12=3D2C 2009=3D2C 12:11 AM
>>>>
>>>>
>>>> Dann Pigdon=3D20
>>>> wrote:
>>>>
>>>>
>>>>> I've seen lots of leopard hunting footage over
>> the
>>>> years=3D2C
>>>>> but I've never seen a leopard leap onto
>>>>> prey from above.
>>>>
>>>>
>>>> I'm sure there are other examples=3D2C but the only
>> mammal I
>>>> can think of that leaps out trees to attack prey
>> on the
>>>> ground is the drop-bear of Australia. British and
>>>> Japanese tourists are its preferred prey.
>>>>
>>>> http://en.wikipedia.org/wiki/Drop_bear
>>>>
>>>>
>>>>
>>>>
>>>> Cheers
>>>>
>>>> Tim
>>>>
>>>>
>>>>
>>>>
>>
>>
>> =3D0A=3D
>> _________________________________________________________________=3D0A=
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