To be fair to the research team, there is no reference in the original
scientific paper to Peregrines striking their prey in the air with their
beaks. The paper can be downloaded online and the details are provided
below. The paper was examining evolutionary divergence of the Peregrine and
Saker Falcons and investigated genes involved in beak development, olfaction
and arid environment-related homeostasis (osmoregulation and
thermoreguation). So it's possible that reference to Peregrines using their
beak to strike prey was artistic licence by the BBC journalist reporting the
story.
Stephen Ambrose
Ryde NSW
Xiangjiang Zhan, Shengkai Pan, Junyi Wang, Andrew Dixon, Jing He,
Margit G Muller, Peixiang Ni, Li Hu, Yuan Liu, Haolong Hou, Yuanping
Chen, Jinquan Xia, Qiong Luo, Pengwei Xu, Ying Chen, Shengguang Liao,
Changchang Cao, Shukun Gao, Zhaobao Wang, Zhen Yue, Guoqing Li, Ye
Yin, Nick C Fox, Jun Wang & Michael W Bruford.
Peregrine and saker falcon genome sequences provide insights into evolution
of a predatory lifestyle.
Nature Genetics (2013) doi:10.1038/ng.2588
Received 13 April 2012 Accepted 28 February 2013 Published online 24
March 2013
Abstract
As top predators, falcons possess unique morphological, physiological and
behavioral adaptations that allow them to be successful hunters: for
example, the peregrine is renowned as the world's fastest animal. To examine
the evolutionary basis of predatory adaptations, we sequenced the genomes of
both the peregrine (Falco peregrinus) and saker falcon (Falco cherrug), and
we present parallel, genome-wide evidence for evolutionary innovation and
selection for a predatory lifestyle. The genomes, assembled using Illumina
deep sequencing with greater than 100-fold coverage, are both approximately
1.2 Gb in length, with transcriptome-assisted prediction of approximately
16,200 genes for both species. Analysis of 8,424 orthologs in both falcons,
chicken, zebra finch and turkey identified consistent evidence for
genome-wide rapid evolution in these raptors. SNP-based inference showed
contrasting recent demographic trajectories for the two falcons, and
gene-based analysis highlighted falcon-specific evolutionary novelties for
beak development and olfaction and specifically for homeostasis-related
genes in the arid environment-adapted saker.
-----Original Message-----
From:
On Behalf Of Angus Innes
Sent: Wednesday, 27 March 2013 7:52 AM
To: Birding Aus
Subject: Peregrines
I had exactly the same reaction as Peter Shute to the BBC report of the
Cardiff Universty study on Peregrine and Saker beaks. The beaks are not
designed for impact as suggested, the feet are - and in the case of the
Peregrine with a built in killing spike.
I reached for J.A. Baker's classic (1967) monograph on "The Peregrine" - the
result of a 10 year study of the bird in and over the woods, marshes and
coast of East Anglia in the UK.
I quote from page 26:"Killing is simple once the peregrine has the advantage
of his prey. Small, light birds are seized in his outstretched foot; larger
heavier birds are stooped at from above, at any angle from ten to ninety
degrees, and are often struck to the ground." The strike is described later:
"The peregrine swoops down towards his prey. As he descends, his legs are
extended forward till the feet are underneath the breast.The toes are
clenched, with the long hind toe projecting below the three front ones,
which are bent up out of the way.He passes close to the bird, almost
touching it with his body, and still moving very fast. his extended hind toe
(or toes- sometimes one, sometimes both) gashes into the back or breast of
the bird, like a knife. At the moment of impact the hawk raises his wings
above his back. If the prey is clean hit- it is usually hit hard or missed
altogether-it dies at once, either from shock or from the perforation of
some vital organ. A peregrin
e weights between 1 1/2 and 2 1/2 lbs: such a weight, falling from a
hundred feet will kill all but the largest birds. Shelduck, pheasants, or
great black-backed gulls, usually succumb to a stoop of five hundred feet or
more." (Baker goes on to describe the use of the beak for tearing open the
choice parts of the prey and for eating.)
Baker conducted all his ornithology in the field, not the laboratory. It is
usually the best starting point.
Angus Innes.
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