@Gábor (10481):
Egy érdekes cikk:
Directional preference may enhance hunting accuracy in foraging foxes
Jaroslav Cervený, Sabine Begall, Petr Koubek, Petra Nováková and Hynek Burda
Biol. Lett. published online 12 January 2011
doi: 10.1098/rsbl.2010.1145
"Recently, we reported that in the absence of strong
extrinsic and intrinsic influences, grazing and resting
cattle and deer prefer to orient their body axes in
roughly north–south directions, i.e. they tend to align
along the geomagnetic field (GMF) lines [1]. No such
directional preference was recorded in animals under
high-voltage power lines, where the GMF is disturbed,
providing direct support for the hypothesis of magnetic
alignment [2]. Magnetic alignment may be a more
widespread phenomenon among animals than previously
thought, which raises questions about its
biological significance."
"When hunting for prey in high cover or under snow,
foxes are unable to use visual cues to augment auditory
cues to target prey. Other predators that specialize on
small mammals, and rely primarily on auditory cues
to locate prey, have evolved specialized mechanisms
to increase the accuracy of prey localization. For
example, barn owls have asymmetrically positioned
ears with the right ear-canal opening higher than the
left one. This asymmetry allows the barn owl to determine
the elevation of a sound by comparing sound
intensity and time differences between its two ears
[12]. The present findings suggest that foxes may
have evolved a different solution to this problem.
First, the fox tilts its head when attending to sounds
produced by a potential prey, creating thus asymmetric
position (different height above the ground) of both
ear-canals. Secondly, as suggested here on the base
of the model presented by Phillips et al. [7], a fox
that approaches an unseen prey along a northward
compass bearing could estimate the distance of its
prey by moving forward until the sound source is in a
fixed relationship to the magnetic field, e.g. it coincides
with the inclination of the magnetic field. This would
consistently place the fox at a fixed distance from its
prey, allowing it to attack using a highly stereotyped
leap (see electronic supplementary material). Thus,
when visual information is limited, using the magnetic
compass to provide a more accurate estimate of distance
from the prey could account for the dramatic increase in
predatory success of attacks aligned to the north and
south field (J. B. Phillips &M. S. Painter 2010, personal
communication). If so, this would be the first documented
case of an animal using magnetic compass input to
estimate distance, rather than direction."
A szerzők szerint jelentős különbség van a rókák vadászati sikerei között, attól függően, hogy milyen geomágneses irányból támad a prédára.
Én meglehetősen szkeptikus vagyok a kijelentéseikkel kapcsolatban.