[Birding-Aus] Article on the Energetics of Bird Migration

[L&L Knight]

The following item may be of interest ...

http://www.sciencedaily.com/releases/2008/05/080513210450.htm

Recipe For Energy Saving Unravelled In Migratory Birds
ScienceDaily (May 13, 2008) — Pointed wings together with carrying
less weight per wing area and avoidance of high winds and atmospheric
turbulence save a bird loads of energy during migration. This has been
shown for the first time in free-flying wild birds by researchers at
Princeton University, the University of Montana, and the German Max
Planck Institute for Ornithology. They state that climate change might
have a critical impact on small migrants' energy budgets if it causes
higher winds and atmospheric instability as predicted.

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[Lawrie Conole]

>Recipe For Energy Saving Unravelled In Migratory Birds
>ScienceDaily (May 13, 2008) — Pointed wings together with carrying
>less weight per wing area and avoidance of high winds and atmospheric
>turbulence save a bird loads of energy during migration. This has been

The wing shape and loading aspects are hardly new. Allen Keast
demonstrated these principles with Australian honeyeaters about 40
years ago! The known migrant and nomad species had longer and more
pointed wings than the sedentary or short-movement species (brutal
summary). From memory Pied, Black and Painted Honeyeaters had the
(relatively speaking) longest and pointiest wings - and they move
probably the longest distances of all the Australian honeyeaters.

Quote from abstract:

"... Wing morphology varies with extent of seasonal movements, a long
pointed wing characterizing Myzomela nigra, Certhionyx variegatus, and
Grantiella picta, whose movements extend the length of the continent.
Within Myzomela there are relative differences in wing-length between
species undertaking extensive, moderate, and no, seasonal movements.
In other genera, and in the case of regional populations within
species, slight to moderate differences are not, however, reflected in
changed wing-form. This could be because the meliphagid wing is
already proportioned for considerable mobility ..."

Ref:

Keast, A. (1968). Seasonal movements in the Australian honeyeaters
(Meliphagidae) and their ecological significance. Emu 67(3): 159 -
209.

--
++++++++++++
Lawrie Conole
28 Reid Street
Northcote, VIC 3070
AUSTRALIA
lconole[at]gmail.com
0419 588 993

[Andrew Taylor]

On Fri, May 16, 2008 at 10:25:11AM +1000, Lawrie Conole wrote:
> The wing shape and loading aspects are hardly new. Allen Keast
> demonstrated these principles with Australian honeyeaters about 40
> years ago!

Yes but measuring in-flight energy consumption of long-distance migrants
in real-time during their migration is definitely a step on.
Paper is publicly available here:
http://www.plosone.org/article/fetchArticle.action?articleURI=info:doi/10.1371/journal.pone.0002154

Andrew
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[Lawrie Conole]

Yes but ... I was really referring to the sloppy referencing in this
paper - all too common in the literature - using recent compendium
references to substantiate the assertion that "... It has long been
accepted that the relatively pointed wingtips of migratory insects,
bats and birds represent the outcome of selection for energy
efficiency during migratory flight ..." rather than going back to some
seminal references - such as Keast's 1968 paper.

No but ... when you look at the method used for attaching the
transmitters (including anaesthetising the birds and holding them
overnight, during which they lost weight), and the admitted low power
of their statistical analyses, I'd be a bit worried about the
robustness of the results! ... interesting as they might be.

--
++++++++++++
Lawrie Conole
28 Reid Street
Northcote, VIC 3070
AUSTRALIA
lconole[at]gmail.com
0419 588 993

[L&L Knight]

Actually I was far more interested in the issue of weather conditions
and the potential impact of climate change on the energy costs ...

Regards, Laurie