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Hi Steve and David,
There are many more of these ultra-migrators being discovered among birds. =
Bar-tailed Godwits are probably the champs. Medium-sized shorebirds (400-63=
0g), they make a non-stop, fall migratory trip of up to 11,000 km in length=
(Alaska to New Zealand) in six to eight days.
Like the Semipalmated Sandpiper, they prepare for migration by accumulating=
a huge amount of fat and reducing the size of some internal structures.
Research also shows that Bar-tailed Godwits are ultra-efficient fat metabol=
izers, producing not only energy from fat but also critical 'metabolic' wat=
er molecules (Answering the question Don't the birds have to drink sometime=
during their migratory flight?). In addition, as the fat is depleted they =
will begin absorbing some organs to complete the journey. Once reaching the=
ir destination they immediately start to rebuild these organs.
I'll leave it to you to determine how this impacts the energy equations you=
used if at all.
All the best,
Lance
Lance Laviolette
Glen Robertson, Ontario
From: naturens-owner@chebucto.ns.ca [mailto:naturens-owner@chebucto.ns.ca] =
On Behalf Of David & Alison Webster
Sent: Saturday, January 24, 2015 8:06 PM
To: naturens@chebucto.ns.ca
Subject: EXTERNAL: Re: [NatureNS] Semipalmated Sandpiper migratory route
Hi Steve & All, Jan 24, 2015
Haldane was just putting the gullible reader on because angels, being s=
pirits, would be weightless (or massless if you wish) so the wings would be=
used variously for ornament, supporting harps, modesty or maneuvering but =
not for lift.
But as you say understanding flight can be complicated, as illustrated =
in a poem (Amer. Sci. 53(1): p. 78, 1965.
Philosophers gravely expound
Metaphysical concepts profound.
While they argue all night
On the meaning of "Flight,"
The Wrights get a plane off the ground.
I leave it to evolution to iterate a useful balance between wing dimens=
ions and body weight and approached the question of flight duration by calc=
ulating rate of fuel consumption (g tallow to keep one gram airborne for on=
e second =3D k) and assumed no additional energy for forward motion; i.e. f=
ighting gravity with a suitable angle of attack would provide both at littl=
e additional cost. Then used differential equations to allow for decrease i=
n weight kept aloft as a function of time and integration to calculate the =
time required to burn a specified amount of tallow. I used 3 g initial and =
1 g final (2 g tallow used) but any initial and final weights could be sub=
stituted by replacing 3 and 1 (2 equations up) with the other numbers.
The full text, with the two typos corrected as noted and with spurious carr=
iage returns thrown in is as follows--
START OF PASTE\\\\\\\\\\\\\\\\\\\\\\\\\
Hi Chris & All, Jan 7, 2002
Your post about 70 hours of non-stop flight got me wondering about ener=
gy
equivalents of fat reserves so I cobbled together an estimate of the upper =
limit.
This is unfamiliar territory so don't bet your life savings that this upper=
imit
is correct. Assumptions are 100% efficiency and zero energy consumed by lif=
e
processes; obviously both wrong but I don't know probable values of efficie=
ncy
and metabolic consumption. No energy is reserved for air resistance or forw=
ard
motion, the idea being that forward motion is a practical way to climb agai=
nst
gravity and maintain height.
GIVEN, ASSUMED:
Acceleration due to gravity (a); a =3D 980.665 cm/sec^2,
One gram.cm =3D 2.3427 x 10^-8 kg.cal,
Tallow heat of combustion =3D 9.5 kg.cal/g
Model bird weighs 3 grams, 2 grams being tallow.
GRAMS TALLOW TO KEEP ONE GRAM WEIGHT AIRBORNE FOR ONE SECOND:
A body at uniform acceleration a, will move in time t, a distance equal=
to s,
i.e.
s =3D 1/2 at^2
So instantaneous ds/dt, to overcome gravity, is
ds/dt=3D at cm/sec =3D 980.665 cm/sec
So the work (energy) required to keep one gram weight airborne for one seco=
nd is
980.665 gram.cm which is equal to
980.665 x 2.3427 x 10^-8 kg.cal =3D 2.297 x 10^-5 kg.cal .
And the grams tallow required to keep one gram weight airborne for one
second,
call this k, is
2.297 x 10^-5 kg.cal/ 9.5 kg.cal/gram=3D 2.4183 x 10^-6 grams tallow/grams
weight.seconds
TIME THAT MODEL BIRD CAN REMAIN AIRBORNE; 3 GRAMS WEIGHT INITIAL, 1 GRAM WE=
IGHT FINAL, 2 GRAMS TALLOW USED:
So if w is instantaneous bird weight, the loss in weight per second will be
dw/dt=3D kw and conversely
dt/dw=3D 1/kw and dt=3D 1/k x dw/w
and T, the seconds to burn 2 g tallow, is the integral (int) of 1/k x dw/w,=
i.e.
T=3D 1/k x int(dw/w)
=3D 1/k x (ln w + c) and for initial and final values of 3 and 1 grams is
=3D1/k x [(ln 3 + c) - (ln 1 + c)] COMMENT =3D>+
=3D 1.0986/k
=3D 4.5428 X 10^5 seconds
=3D ~126 hours
Note that (ln 30 - ln 10) is also equal to 1.0986, so as long as proportion=
s of
initial and final weight remain the same, the same upper limit for airborne
time will apply. COMMENT ln 20 THREE LINES UP CHANGED TO ln 10
This also explains why it is so difficult to work off that extra servin=
g
of rich gravy.
Yours truly, Dave Webster, Kentville
END OF PASTE\\\\\\\\\\\\\\\
----- Original Message -----
From: Stephen Shaw<mailto:srshaw@Dal.Ca>
To: naturens@chebucto.ns.ca<mailto:naturens@chebucto.ns.ca>
Sent: Saturday, January 24, 2015 6:46 PM
Subject: Re: [NatureNS] Semipalmated Sandpiper migratory route
Hi Dave et al,
This is perhaps splitting hairs because the Sandpiper (28g) and Blackpoll W=
arbler (European, probably ~10-11g) are both quite small birds and therefor=
e may be nearly equivalent, but any calculation needs to be framed in terms=
of what mass has to be kept aloft. It would take far more fuel consumption=
per hour to keep a heavy crow (450g) in the air compared to that for a sma=
ll light warbler, if they have similarly efficient lift-generating wings (d=
oubtful). It is usually framed in terms of body mass being proportional to=
the cube of the average linear dimension (LD^3), while lift generation is =
proportional to the square of the LD (LD^2) - so you need proportionally mo=
re wing lift area as the body mass increases until it finally becomes infea=
sible to fly at all - from memory the Great Bustard was reckoned to be the =
most massive bird that could still manage to fly.
I may have used this example before: biologist J.B.S. Haldane (an atheist) =
once penned a mischievous essay on the impossibility of the existence of an=
gels, at least in their depiction in medieval manuscripts, because to power=
wings that size (a big LD^2) would require a breastbone extending down to =
the ground to carry the enormous muscles required to flap them (humungous L=
D^3), not so illustrated in the manuscripts.
Albatrosses don't count much in this because an engineer C. Pennycuick (sp?=
) in the 1960s calculated that one species he looked at mostly used the upd=
raft from wave crests to glide along on a sinuous path using lift energy de=
rived from that, somewhat analogous to the larger scale thermals used by so=
me migrating raptors and storks.
Understanding flight is complicated.
Steve (Hfx)
On Jan 24, 2015, at 3:33 PM, David & Alison Webster <dwebster@glinx.com<mai=
lto:dwebster@glinx.com>> wrote:
Hi Angus & All, Jan 24, 2015
In an e-mail of Jan 7, 2002 I estimated maximum flight duration based o=
n energy content of tallow and with initial conditions of 3 g total weight =
of which 2 g is tallow to be 126 hours (what I call weight would usually no=
w be called mass). In scanning this quickly I noticed two typos but whether=
these introduced error I don't know.
At that time Richard dug out an example which showed this simple model =
to considerably underestimate actual endurance--
START OF PASTE\\\\\\\\\\\\\\\
Hi Richard, Elizabeth & All, Jan 9, 2002
<SNIP>
> -- "A typical Blackpoll Warbler at the end of its
> breeding season weighs about 11 grams, equivalent to the weight of 4
> pennies. In preparing for its transatlantic trek, it may accumulate enoug=
h
> fat reserves to increase its body weight to 21 grams. Given an in-flight =
fat
> consumption rate of 0.6% of its body weight per hour, the bird then has
> enough added fuel for approximately 90 hours of flight for a journey whic=
h,
> under fair conditions, requires about 80 to 90 hours.
This Warbler beats my upper limit, perhaps by being a good weather
forecaster and using rising air currents.
My k equates to a loss of 0.87% of body weight per hour compared to 0.6=
%
loss in the Warbler. And when I plug 21 and 11 grams into my model, I get 7=
4
hours of flight compared to 90 hours for the Warbler.
Yours truly, Dave Webster, Kentville
END OT PASTE\\\\\\\\\\\\\\\
And the link below, for the Semipalmated Warbler, has 6 days of non-sto=
p flight over water (~144 hours).
The Albatross beats all of the above of course by staying aloft for yea=
rs without beating a wing. Holding wings out and tilting them and tail as r=
equired takes energy but still it manages amazingly efficient flight.
Yt, Dave Webster, Kentville
----- Original Message -----
From: Angus MacLean<mailto:cold_mac@hotmail.com>
To: naturens<mailto:naturens@chebucto.ns.ca>
Sent: Saturday, January 24, 2015 9:34 AM
Subject: RE: [NatureNS] Semipalmated Sandpiper migratory route
Can't imagine how thin that little guy was when it arrived at the Orinoco D=
elta!!
Thanks, Eric.
Angus
________________________________
From: E.Mills@Dal.Ca<mailto:E.Mills@Dal.Ca>
To: naturens@chebucto.ns.ca<mailto:naturens@chebucto.ns.ca>
CC: davidmary3@eastlink.ca<mailto:davidmary3@eastlink.ca>
Subject: [NatureNS] Semipalmated Sandpiper migratory route
Date: Sat, 24 Jan 2015 01:31:03 +0000
Courtesy of BCVIBirds, here is a fascinating link about the migratory paths=
of Semipalmated Sandpipers that stage in James Bay: http://goo.gl/at0GMZ
I suspect that geolocators have been used with east coast migrants as well,=
but I don't have that information.
Eric
Eric L. Mills
Lower Rose Bay
Lunenburg Co., NS
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<div class=3D"WordSection1">
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D">Hi Steve and David,<o:p><=
/o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D">There are many more of th=
ese ultra-migrators being discovered among birds. Bar-tailed Godwits are pr=
obably the champs. Medium-sized shorebirds (400-630g), they
make a non-stop, fall migratory trip of up to 11,000 km in length (Alaska =
to New Zealand) in six to eight days.
<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D">Like the Semipalmated San=
dpiper, they prepare for migration by accumulating a huge amount of fat and=
reducing the size of some internal structures.<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D">Research also shows that =
Bar-tailed Godwits are ultra-efficient fat metabolizers, producing not only=
energy from fat but also critical ‘metabolic’ water molecules
(Answering the question <i>Don’t the birds have to drink sometime du=
ring their migratory flight?</i>). In addition, as the fat is depleted they=
will begin absorbing some organs to complete the journey. Once reaching th=
eir destination they immediately start
to rebuild these organs. <o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D">I’ll leave it to yo=
u to determine how this impacts the energy equations you used if at all.
<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D">All the best,<o:p></o:p><=
/span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D">Lance<o:p></o:p></span></=
p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><b><span style=3D"font-size:14.0pt;font-family:"=
;Batang","serif";color:#1F497D">Lance Laviolette<o:p></o:p><=
/span></b></p>
<p class=3D"MsoNormal"><span style=3D"font-size:10.0pt;font-family:"Ba=
tang","serif";color:#1F497D">Glen Robertson, Ontario<o:p></o=
:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";color:#1F497D"><o:p> </o:p></span><=
/p>
<div>
<div style=3D"border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in =
0in 0in">
<p class=3D"MsoNormal"><b><span lang=3D"EN-US" style=3D"font-size:10.0pt;fo=
nt-family:"Tahoma","sans-serif"">From:</span></b><span =
lang=3D"EN-US" style=3D"font-size:10.0pt;font-family:"Tahoma",&qu=
ot;sans-serif""> naturens-owner@chebucto.ns.ca [mailto:naturens-owner@=
chebucto.ns.ca]
<b>On Behalf Of </b>David & Alison Webster<br>
<b>Sent:</b> Saturday, January 24, 2015 8:06 PM<br>
<b>To:</b> naturens@chebucto.ns.ca<br>
<b>Subject:</b> EXTERNAL: Re: [NatureNS] Semipalmated Sandpiper migratory r=
oute<o:p></o:p></span></p>
</div>
</div>
<p class=3D"MsoNormal"><o:p> </o:p></p>
<div>
<p class=3D"MsoNormal">Hi Steve & All, &n=
bsp; &=
nbsp; =
Jan 24, 2015<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> Haldane was just putting the gull=
ible reader on because angels, being spirits, would be weightless (or massl=
ess if you wish) so the wings would be used variously for ornament, su=
pporting harps, modesty or maneuvering but not for lift.
<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> <o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> But as you say understanding flig=
ht can be complicated, as illustrated in a poem (Amer.=
Sci. 53(1): p. 78, 1965.<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> <o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal">Philosophers gravely expound<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal">Metaphysical concepts profound.<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal">While they argue all night<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal">On the meaning of "Flight,"<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> The Wrights get a plane off the ground.<o:p></=
o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> <o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> I leave it to evolution to iterat=
e a useful balance between wing dimensions and body weight and ap=
proached the question of flight duration by calculating rate of fuel consum=
ption (g tallow to keep one gram airborne for one second =3D
k) and assumed no additional energy for forward motion; i.e. fighting=
gravity with a suitable angle of attack would provide both at little addit=
ional cost. Then used differential equations to allow for decrease in =
weight kept aloft as a function of time and
integration to calculate the time required to burn a specified amount of t=
allow. I used 3 g initial and 1 g final (2 g tallow used) but any ini=
tial and final weights could be substituted by replacing 3 and 1 (2 equatio=
ns up) with the other numbers.<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> <o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal">The full text, with the two typos corrected as noted=
and with spurious carriage returns thrown in is as follows--<o:p></o:p></p=
>
</div>
<div>
<p class=3D"MsoNormal">START OF PASTE\\\\\\\\\\\\\\\\\\\\\\\\\<o:p></o:p></=
p>
</div>
<div>
<p class=3D"MsoNormal">Hi Chris & All, &nb=
sp; Jan 7, 2002<br>
Your post about 70 hours of non-stop flight got me wonde=
ring about energy<br>
equivalents of fat reserves so I cobbled together an estimate of the upper =
limit.<br>
This is unfamiliar territory so don't bet your life savings that this upper=
imit<br>
is correct. Assumptions are 100% efficiency and zero energy consumed by lif=
e<br>
processes; obviously both wrong but I don't know probable values of efficie=
ncy<br>
and metabolic consumption. No energy is reserved for air resistance or forw=
ard<br>
motion, the idea being that forward motion is a practical way to climb agai=
nst<br>
gravity and maintain height.<br>
GIVEN, ASSUMED:<br>
Acceleration due to gravity (a); a =3D 980.665 cm/sec^2,<br>
One gram.cm =3D 2.3427 x 10^-8 kg.cal,<br>
Tallow heat of combustion =3D 9.5 kg.cal/g<br>
Model bird weighs 3 grams, 2 grams being tallow.<br>
GRAMS TALLOW TO KEEP ONE GRAM WEIGHT AIRBORNE FOR ONE SECOND:<br>
A body at uniform acceleration a, will move in time t, a=
distance equal to s,<br>
i.e.<br>
s =3D 1/2 at^2<br>
So instantaneous ds/dt, to overcome gravity, is<br>
ds/dt=3D at cm/sec =3D 980.665 cm/sec<br>
So the work (energy) required to keep one gram weight airborne for one seco=
nd is<br>
980.665 gram.cm which is equal to<br>
980.665 x 2.3427 x 10^-8 kg.cal =3D 2.297 x 10^-5 kg.cal .<br>
And the grams tallow required to keep one gram weight airborne for one <br>
second,<br>
call this k, is<br>
2.297 x 10^-5 kg.cal/ 9.5 kg.cal/gram=3D 2.4183 x 10^-6 grams tallow/grams<=
br>
weight.seconds<br>
TIME THAT MODEL BIRD CAN REMAIN AIRBORNE; 3 GRAMS WEIGHT INITIAL, 1 GRAM WE=
IGHT FINAL, 2 GRAMS TALLOW USED:<br>
So if w is instantaneous bird weight, the loss in weight per second will be=
<br>
dw/dt=3D kw and conversely<br>
dt/dw=3D 1/kw and dt=3D 1/k x dw/w<br>
and T, the seconds to burn 2 g tallow, is the integral (int) of 1/k x dw/w,=
i.e.<br>
T=3D 1/k x int(dw/w)<br>
=3D 1/k x (ln w + c) and for initial and final values of 3 and 1=
grams is<br>
=3D1/k x [(ln 3 + c) - (ln 1 + c)] &n=
bsp; COMMENT =3D>+<br>
=3D 1.0986/k<br>
=3D 4.5428 X 10^5 seconds<br>
=3D ~126 hours<br>
Note that (ln 30 - ln 10) is also equal to 1.0986, so as long as proportion=
s of<br>
initial and final weight remain the same, the same upper limit for airborne=
<br>
time will apply. COMMENT ln 20 THREE LINES UP CHANGED TO ln 10<br>
This also explains why it is so difficult to work off th=
at extra serving <br>
of rich gravy.<br>
<br>
Yours truly, Dave Webster, Kentville<br>
END OF PASTE\\\\\\\\\\\\\\\<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> <o:p></o:p></p>
</div>
<blockquote style=3D"border:none;border-left:solid black 1.5pt;padding:0in =
0in 0in 4.0pt;margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-b=
ottom:5.0pt">
<div>
<p class=3D"MsoNormal"><span style=3D"font-size:10.0pt;font-family:"Ar=
ial","sans-serif"">----- Original Message -----
<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal" style=3D"background:#E4E4E4"><b><span style=3D"font-=
size:10.0pt;font-family:"Arial","sans-serif"">From:</sp=
an></b><span style=3D"font-size:10.0pt;font-family:"Arial","=
sans-serif"">
Stephen Shaw <=
o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><b><span style=3D"font-size:10.0pt;font-family:"=
;Arial","sans-serif"">To:</span></b><span style=3D"font-size=
:10.0pt;font-family:"Arial","sans-serif"">
<a href=3D"mailto:naturens@chebucto.ns.ca" title=3D"naturens@chebucto.ns.ca=
">naturens@chebucto.ns.ca</a>
<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><b><span style=3D"font-size:10.0pt;font-family:"=
;Arial","sans-serif"">Sent:</span></b><span style=3D"font-si=
ze:10.0pt;font-family:"Arial","sans-serif""> Saturday, =
January 24, 2015 6:46 PM<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><b><span style=3D"font-size:10.0pt;font-family:"=
;Arial","sans-serif"">Subject:</span></b><span style=3D"font=
-size:10.0pt;font-family:"Arial","sans-serif""> Re: [Na=
tureNS] Semipalmated Sandpiper migratory route<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><o:p> </o:p></p>
</div>
<p class=3D"MsoNormal">Hi Dave et al, <o:p></o:p></p>
<div>
<p class=3D"MsoNormal">This is perhaps splitting hairs because the Sandpipe=
r (28g) and Blackpoll Warbler (European, probably ~10-11g) are both quite s=
mall birds and therefore may be nearly equivalent, but any calculation need=
s to be framed in terms of what mass
has to be kept aloft. It would take far more fuel consumption per hour to =
keep a heavy crow (450g) in the air compared to that for a small light warb=
ler, if they have similarly efficient lift-generating wings (doubtful). &nb=
sp;It is usually framed in terms of body
mass being proportional to the cube of the average linear dimension (LD^3)=
, while lift generation is proportional to the square of the LD (LD^2) R=
12; so you need proportionally more wing lift area as the body mass increas=
es until it finally becomes infeasible
to fly at all — from memory the Great Bustard was reckoned to be the=
most massive bird that could still manage to fly. <o:p></o:p><=
/p>
</div>
<div>
<p class=3D"MsoNormal">I may have used this example before: biologist J.B.S=
. Haldane (an atheist) once penned a mischievous essay on the impossibility=
of the existence of angels, at least in their depiction in medieval manusc=
ripts, because to power wings that
size (a big LD^2) would require a breastbone extending down to the ground =
to carry the enormous muscles required to flap them (humungous LD^3), not s=
o illustrated in the manuscripts.<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal">Albatrosses don’t count much in this because a=
n engineer C. Pennycuick (sp?) in the 1960s calculated that one species he =
looked at mostly used the updraft from wave crests to glide along on a sinu=
ous path using lift energy derived from
that, somewhat analogous to the larger scale thermals used by some migrati=
ng raptors and storks. <o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal">Understanding flight is complicated.<o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal">Steve (Hfx) <o:p></o:p></p>
</div>
<div>
<p class=3D"MsoNormal"> &nb=
sp; <o:p></o:p></p>
<div>
<div>
<p class=3D"MsoNormal">On Jan 24, 2015, at 3:33 PM, David & Alison Webs=
ter <dwebster@glinx.com> wr=
ote:<o:p></o:p></p>
</div>
<p class=3D"MsoNormal"><br>
<br>
<o:p></o:p></p>
<div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Arial","s=
ans-serif"">Hi Angus & All, &=
nbsp; =
Jan 24, 2015</span><span style=3D"font-family:"Cali=
bri","sans-serif""><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Arial","s=
ans-serif""> In an e-mail of Jan 7, 2002 I estimated=
maximum flight duration based on energy content of tallow and with in=
itial conditions of 3 g total weight of which 2 g is tallow to be 126 hours
(what I call weight would usually now be called mass). In scanning th=
is quickly I noticed two typos but whether these introduced error I don't k=
now.</span><span style=3D"font-family:"Calibri","sans-serif&=
quot;"><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Arial","s=
ans-serif""> At that time Richard dug out an example=
which showed this simple model to considerably underestimate actual endura=
nce--</span><span style=3D"font-family:"Calibri","sans-serif=
""><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Arial","s=
ans-serif"">START OF PASTE\\\\\\\\\\\\\\\</span><span style=3D"font-fa=
mily:"Calibri","sans-serif""><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif"">Hi Richard, Elizabeth & All, =
Jan 9, 2=
002<br>
<span class=3D"apple-converted-space"> </span></span=
><span style=3D"font-family:"Arial","sans-serif""><S=
NIP></span><span style=3D"font-family:"Calibri","sans-ser=
if""><br>
> -- "A typical Blackpoll Warbler at the end of its<br>
> breeding season weighs about 11 grams, equivalent to the weight of 4<b=
r>
> pennies. In preparing for its transatlantic trek, it may accumulate en=
ough<br>
> fat reserves to increase its body weight to 21 grams. Given an in-flig=
ht fat<br>
> consumption rate of 0.6% of its body weight per hour, the bird then ha=
s<br>
> enough added fuel for approximately 90 hours of flight for a journey w=
hich,<br>
> under fair conditions, requires about 80 to 90 hours.<br>
<br>
This Warbler beats my upper limit, perhaps by being a go=
od weather<br>
forecaster and using rising air currents.<br>
My k equates to a loss of 0.87% of body weight per hour =
compared to 0.6%<br>
loss in the Warbler. And when I plug 21 and 11 grams into my model, I get 7=
4<br>
hours of flight compared to 90 hours for the Warbler.<br>
<br>
Yours truly, Dave Webster, Kentville<br>
</span><span style=3D"font-family:"Arial","sans-serif""=
>END OT PASTE\\\\\\\\\\\\\\\</span><span style=3D"font-family:"Calibri=
","sans-serif""><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif""> <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Arial","s=
ans-serif""> And the link below, for the Semipalmate=
d Warbler, has 6 days of non-stop flight over water (~144 hours).</span><sp=
an style=3D"font-family:"Calibri","sans-serif""><o:p></=
o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif""> <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Arial","s=
ans-serif""> The Albatross beats all of the above of=
course by staying aloft for years without beating a wing. Holding wings ou=
t and tilting them and tail as required takes energy but still it manages
amazingly efficient flight.</span><span style=3D"font-family:"Calibri=
","sans-serif""><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif""> <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Arial","s=
ans-serif"">Yt, Dave Webster, Kentville</span><span style=3D"font-fami=
ly:"Calibri","sans-serif""><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif""> <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif""> <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif""> <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif""><br>
----- Original Message -----<o:p></o:p></span></p>
</div>
<blockquote style=3D"border:none;border-left:solid black 1.5pt;padding:0in =
0in 0in 4.0pt;margin-left:3.75pt;margin-top:5.0pt;margin-right:0in;margin-b=
ottom:5.0pt">
<div>
<p class=3D"MsoNormal" style=3D"background:#E4E4E4"><b><span style=3D"font-=
size:10.0pt;font-family:"Arial","sans-serif"">From:</sp=
an></b><span class=3D"apple-converted-space"><span style=3D"font-size:10.0p=
t;font-family:"Arial","sans-serif""> </span></span=
><span style=3D"font-size:10.0pt;font-family:"Arial","sans-s=
erif""><a href=3D"mailto:cold_mac@hotmail.com" title=3D"cold_mac@hotma=
il.com">Angus
MacLean</a><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><b><span style=3D"font-size:10.0pt;font-family:"=
;Arial","sans-serif"">To:</span></b><span class=3D"apple-con=
verted-space"><span style=3D"font-size:10.0pt;font-family:"Arial"=
,"sans-serif""> </span></span><span style=3D"font-size:10.0p=
t;font-family:"Arial","sans-serif""><a href=3D"mailto:n=
aturens@chebucto.ns.ca" title=3D"naturens@chebucto.ns.ca">naturens</a><o:p>=
</o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><b><span style=3D"font-size:10.0pt;font-family:"=
;Arial","sans-serif"">Sent:</span></b><span class=3D"apple-c=
onverted-space"><span style=3D"font-size:10.0pt;font-family:"Arial&quo=
t;,"sans-serif""> </span></span><span style=3D"font-size:10.=
0pt;font-family:"Arial","sans-serif"">Saturday,
January 24, 2015 9:34 AM<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><b><span style=3D"font-size:10.0pt;font-family:"=
;Arial","sans-serif"">Subject:</span></b><span class=3D"appl=
e-converted-space"><span style=3D"font-size:10.0pt;font-family:"Arial&=
quot;,"sans-serif""> </span></span><span style=3D"font-size:=
10.0pt;font-family:"Arial","sans-serif"">RE:
[NatureNS] Semipalmated Sandpiper migratory route<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif""><o:p> </o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal" style=3D"margin-bottom:12.0pt"><span style=3D"font-f=
amily:"Calibri","sans-serif"">Can't imagine how thin th=
at little guy was when it arrived at the Orinoco Delta!!<br>
Thanks, Eric.<br>
Angus<o:p></o:p></span></p>
<div>
<div class=3D"MsoNormal" align=3D"center" style=3D"text-align:center"><span=
style=3D"font-family:"Calibri","sans-serif"">
<hr size=3D"2" width=3D"100%" align=3D"center" id=3D"stopSpelling">
</span></div>
<p class=3D"MsoNormal" style=3D"margin-bottom:12.0pt"><span style=3D"font-f=
amily:"Calibri","sans-serif"">From:<span class=3D"apple=
-converted-space"> </span><a href=3D"mailto:E.Mills@Dal.Ca">E.Mills@Da=
l.Ca</a><br>
To:<span class=3D"apple-converted-space"> </span><a href=3D"mailto:nat=
urens@chebucto.ns.ca">naturens@chebucto.ns.ca</a><br>
CC:<span class=3D"apple-converted-space"> </span><a href=3D"mailto:dav=
idmary3@eastlink.ca">davidmary3@eastlink.ca</a><br>
Subject: [NatureNS] Semipalmated Sandpiper migratory route<br>
Date: Sat, 24 Jan 2015 01:31:03 +0000<o:p></o:p></span></p>
<div id=3D"ecxdivtagdefaultwrapper">
<p class=3D"MsoNormal" style=3D"margin-bottom:12.0pt;background:white"><spa=
n style=3D"font-family:"Calibri","sans-serif"">Courtesy=
of BCVIBirds, here is a fascinating link about the migratory paths of Semi=
palmated Sandpipers that stage in James Bay:<span class=3D"apple-converted-=
space"> </span><a href=3D"http://goo.gl/at0GMZ" target=3D"_blank">http=
://goo.gl/at0GMZ</a><br>
<br>
<br>
I suspect that geolocators have been used with east coast migrants as well,=
but I don't have that information.<br>
<br>
<br>
Eric<br>
<br>
<br>
Eric L. Mills<br>
Lower Rose Bay<br>
Lunenburg Co., NS<o:p></o:p></span></p>
</div>
</div>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif"">No virus found in this message.<br>
Checked by AVG -<span class=3D"apple-converted-space"> </span><a href=
=3D"http://www.avg.com/">www.avg.com</a><br>
Version: 2015.0.5645 / Virus Database: 4273/8984 - Release Date: 01/23/15<o=
:p></o:p></span></p>
</div>
</blockquote>
</div>
</div>
<p class=3D"MsoNormal"><o:p> </o:p></p>
</div>
<p>No virus found in this message.<br>
Checked by AVG - www.avg.com<br>
Version: 2015.0.5645 / Virus Database: 4273/8993 - Release Date: 01/24/15<o=
:p></o:p></p>
</blockquote>
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