Photos of the multi-million Brambling flock in Austria

[AndyB]

Lajos Nemeth-Boka has posted a few photos of a flock of 2-4 million birds at Lödersdorf, Austria on Euro Stop Press (http://www.surfbirds.com/cgi-bin/gallery/display.cgi?gallery=gallery11)

http://www.surfbirds.com/media/gallery_photos/20090118045131.JPG
" I know it is a common bird, but a rare sight, some 2-4million birds roosting together. Birding highlight for years for me, a must see." Brambling, Austria, Lödersdorf 17/Jan/2009 © Lajos Nemeth-Boka/GreenEye Ecotours

http://www.surfbirds.com/media/gallery_photos/20090118045232.JPG
"It was just incredible. Four years ago probably the same flock roosted in a very similar setting in Slovenia." Brambling, Austria, Lödersdorf 17/Jan/2009 © Lajos Nemeth-Boka/GreenEye Ecotours

[Morg]

There are videoclips available on YouTube. Would love to go and see this - a flock of a few hundred finches can be pretty impressive so this one must be fantastic.

Geoff

try

http://uk.youtube.com/watch?v=5JLvUbSBhz8

[MichaelF]

My count's doing well, 2,345,678, .. 2,345,679, .. 2,345,680, .. whoops! flushed by a Sparrowhawk:swoon: . . . oh well, start again, 1, 2, 3, 4, 5, ....

[Brian S]

Amazing. However, think of the numbers of Passenger Pigeons there used to be,

'In the spring of 1749....there came from the north an incredible multitude of these pigeons to Pennsylvania and New Jersey. Their number, while in flight exceeded three or four miles in length and more than one such mile in breadth, and they flew so closely together that the sky and the sun were obscured..'

Colonies were at times colossal, sometimes said to be 160km in length, and yet, despite the numbers of Passenger Pigeons thought to be the equivalent of 25-40% of the total number of landbirds in the US, through hunting (prizes in hunting competitions could only be given out to bags of over 30,000 birds), they were to become extinct.

The last Passenger Pigeon, called 'Martha', was found dead on Tuesday 1st September 1914 at 1pm precisely - perhaps the only time the extinction of a species is known to the exact minute. A sad and salutory tale....

Brian S

Ref. Fuller E., 1987. 'Extinct Birds', Cornell University Press.

[Alex Lees]

Hi Brian, all

Although the proximate reason for the extinction of the Passenger Pigeon was overhunting, it was an allee effect that kicked in to provide the ultimate reason for the species' extinction. Fragmentation of the mast forests on which the species relied (draw parrallels with Brambling), intensive exploitation and large, natural fluctuations in population size might have brought flocks below a lower, unstable equilibrium, resulting from decreased foraging efficiency at reduced flock sizes and a failure to nest when there weren't millions of birds around. The species basically stopped breeding even when it was no longer hunted and became extinct in a couple of generations. The effects of this loss are still being felt - see speculative note below. Anyone interested should read the seminal paper in Biol Con (also attached), a warning that should echo across the globe.

cheers

Alex

-------
Science 20 March 1998: Vol. 279. no. 5358, p. 1831
Letters
There is another possible twist to the complicated ecological chain of events presented by Clive G. Jones et al. (Reports, 13 Feb., p. 1023) whereby the incidence of Lyme disease might increase following population increases of mice allowed by a big mast year of acorns. A major competitor of deer and mice for these bumper crops has been absent from the eastern deciduous forests for a century. The extinct passenger pigeon (Ectopistes migratorius) was a nomadic wanderer that specialized on a diet of the superabundant, but unpredictable, crops of mast (1). With a population estimated at 2 to 5 billion (2), concentrated in enormous flocks, passenger pigeons congregated wherever there were huge crops of mast. The birds were so efficient at denuding the woods of nuts that many observers noted that native wildlife and feral hogs could not find sufficient food after a pigeon flock had passed through (2). Is it possible that, in the presence of passenger pigeons, the population explosions of mice in mast years, reported by Jones et al., would have been less likely. Could the outbreaks of Lyme disease in the late 20th century have been a delayed consequence of the extinction of the passenger pigeon a century earlier?

David E. Blockstein
Senior Scientist,
Committee for the National
Institute for the Environment,
1725 K Street NW
Washington, DC, 20006-1401, USA
E-mail:david@cnie.org

--------------------------------------------------------------------------------
References

D. Blockstein and H. Tordoff, Am. Birds 39, 845 (1985).
A. Schorger, The Passenger Pigeon (Univ. of Wisconsin Press, Madison, WS, 1955).

[Nigel Lindsey]

Hi

Whilst amazing it is still small by Brambling standards - the record seems to be a roost in Thun Switzerland in 1950-51 estimated at 70-72 million although the BBC website claims flocks of 100 million feeding on beechmast in Germany. My source for this is the AA/Reader's Digest book of British Birds but there appear to be articles in Ibis that corroborate it although I can't download them.

Nigel

[MichaelF]

Remember reading somewhere (sorry, can't remember where!) that those huge counts are no longer considered reliable, with ~5 million the largest counts now accepted as verifiable.

[Colin Key]

If Nigel's reference to the roost in Thun, Switzerland was true, the estimated "70 to 72 million" is quite a precise figure (as opposed to saying ""approximately 70 million"). How do people count birds in numbers of that magnitude?

Colin :err:

[Brian S]

Imagine the biomass of 70-72 million Brambling.

BWP gives various weights for males that average c.25g and for females that average c.23g. So taking 24g as the average weight of a Brambling (I know someone will come back and try to give weights for young birds as well.....), we come up with 1,680,000,000g or 1,680,000kg or 1,680 tonnes.

If an African Elephant weighs an average of 5.5 tonnes, then this size flock equates to 305.5 elephants. A Blue Whale weighs 100-160 tonnes, so is equal to about 13 Blue Whales.

Imagine them sat in the trees near Thun.....:laugh:

Brian S

[Alex Lees]

Imagine the biomass of 70-72 million Brambling.

BWP gives various weights for males that average c.25g and for females that average c.23g. So taking 24g as the average weight of a Brambling (I know someone will come back and try to give weights for young birds as well.....), we come up with 1,680,000,000g or 1,680,000kg or 1,680 tonnes.

If an African Elephant weighs an average of 5.5 tonnes, then this size flock equates to 305.5 elephants. A Blue Whale weighs 100-160 tonnes, so is equal to about 13 Blue Whales.

Imagine them sat in the trees near Thun.....:laugh:

Brian S

BWP states a revised estimate of 4-10 million for the mega counts of '50-'51, I don't have the obscurish paper cited as the source, but it seems that the way the counts (of 70+ million birds) were extrapolated was dubious. This estimate gives us a biomass estimate roughly one order of magnitude lower than Brian's, but still enough 'bling to give Bobby George food for thought. The current flock probably represents about 8-10% of the European population.

Alex

[MichaelF]

but still enough 'bling to give Bobby George food for thought

Ouch. .......

[Colin Key]

If an African Elephant weighs an average of 5.5 tonnes, then this size flock equates to 305.5 elephants. A Blue Whale weighs 100-160 tonnes, so is equal to about 13 Blue Whales.

Imagine them sat in the trees near Thun.....:laugh:

Brian S

I do recall seeing a couple of elephants sitting in an almond tree - they were pink, and it was on New Year's Eve.

Colin :laugh::beer::laugh::beer::laugh:

[MichaelF]

:no:Sorry, but that just shows your poor i.d. skills . . . I checked in the Records Committee files, the tree was a pear Pyrus communis not an almond, the occupant a Grey Partridge not a Pink Elephant, and there was just one of them, not two.
:tongue::biggrin:

[Colin Key]

:laugh::laugh::laugh:

Who, or what, is Bobby George"?

Colin :err:

[MichaelF]

Who, or what, is Bobby George"?

No idea, but presumably some chav or other loaded with bling. Try this character: http://en.wikipedia.org/wiki/Bobby_George

[Colin Key]

Ahh,

A darts player, hence a big fat b@stard, therefore the link to elephants and whales (I assume?).

Must be the most obscure reference ever, on this forum.

Colin :err::SLEEP:

[Colin Key]

SPAM reported. My goodness, they are getting clever; had it not been for that third image I would not have seen the link at the end of the post.

Colin :hmpf:

[michael23]

well spotted colin, i looked at it earlier and missed it!

[Michael T]

Certainly an impressive sight! I don't know what the size of a flock of Red billed Queleas is? But with an approximate population of 1.5 billion! they woud probably be one of the biggest flocks of any bird alive today.