Some barn owl use a noteworthy and antagonistic - intuitive method to catch their quarry . By developing livid feather on their underside , these predators have lost the vantage of camouflage but gain something even advantageously in return – the mental ability to dazzle their prey for easygoing seizure .
When confronted with vivid light some nocturnal animal freeze like , well , a rabbit ( or deer ) caught in headlight . The number of roadside carcasses testifies to the drawbacks of this response , but cars are too new to have applied much selection pressure on these creatures . What is much more puzzling is the find , byDr Luis San - Joseof the University of Lausanne , that owls have been making utilisation of the same phenomenon , presumptively for millions of year .
San - Jose was struck by the fact male barn owls make out with two color system – one ruddy - brown over the entire body , the other white feathers on the front . In theory , red owl should be able to successfully sneak up on quarry that might be alert to an approaching predator by a jiffy of white feathers , yet the white morph thrives .
InNature Ecology and Evolution , San - Jose and co - authors describe a series of experiments that excuse white barn owls ’ success . Cameras placed in owl nests and GPS tracker on the owls themselves reveal that around the full Moon the reddish owls view 43 percent less quarry and their owlets often decease hungry . ostensibly any advantages the bird of Minerva might get ahead from seeing their prey in moonlight were more than offset by the drawback of the prey being able-bodied to see them too . distaff owls with red partners even time testicle - laying so the owlets are not at their most vulnerable around full Moon .
Strangely , however , the blank - belly out owls , which one would expect to be even more visible at full Moon , hurt no drop off in their run success .
To explain this paradox San - Jose put taxidermied owls on ziplines and “ flew ” them over voles , the barn owl ' favorite prey . He obtain that vole “ froze ” for long when they saw a white owl illuminate by light equivalent to a full Moon – five seconds longer than a ruby-red owl and almost 10 second longer than under new Moon conditions . Far from assisting escape , the extra admonition voles get during this Moon stage left them more volnerable ( sorry , not sorry ) to catch , but only by the bird of night with white enough front to bedazzle the field mouse .
The white bird of Minerva caught slimly fewer quarry during the duller fresh Moon and under muddy skies , possibly explain why not all barn owls are blank , although the authors also suggest cerise hooter benefit from daytime camouflage .
AsDr Jesús Avilésnotes in an accompanyingNews and Views , what is puzzling here is why vole have not evoleved ( still not drear ) to freeze less when they have been face this monthly threat from above for eons .
