For expectant meat eaters , that mouthwatering smell of blood comes down to a undivided molecule . Researchers working with four large piranha species establish that one special constituent of stock odor was just as enticing as the smell of real blood itself . Thestudywas bring out inPLOS ONEthis workweek .
" For predatory animal , nutrient scents are particularly attractive , and much of this has to do with blood,“Matthias Laska of Linköping Universitysays in anews release . “ We want to find out which chemical constituent produce the odour of blood . ” Recent analyses of the composing of volatile in mammal line reveal that the compound trans-4,5 - epoxy-(E)-2 - decenal is what emit that metallic , bloodline - like odor caliber ( to us at least ) . This aldehyde forms when beast fat breaks down .
To test if this odorant component is what draws predator to rake , Laska and colleagues observed the behavior of four engrossed species at Kolmården Wildlife Park in Sweden : Asiatic wild dog , African wild firedog , South American bush dogs , and Siberian World Tamil Association . They presented the animals with half - meter - long spruce log that were douse with either horse origin or trans-4,5 - epoxy-(E)-2 - decenal . Then the researchers liken these reactions to their behavior towards log drenched with a fruity , banana - same odor ( isopentyl acetate ) and a cheeseparing - odorless solvent ( diethyl phthalate ) as mastery . The animals were exposed to one of the four scent a mean solar day in their regular enclosure ; they did this five times for a total of 20 experimental days per species .
The logs saturate with the aldehyde were just as attractive as those incorporate real blood . The predators sniff , licked , bit , pawed , and toyed with both “ bloody ” logs , and there were no significant differences between the number of interaction between the aldehyde - laced and bloodline - soaked log . They ’d also guard and roost near to ( sometimes on top of ) the odorized log – as if they were bones leftover from a repast . The two non - prey - associated logs arouse little pastime .
In this image ( clockwise from upper left wing ) , you may see an African violent dog sniffing at an odorized wooden logarithm , two Asiatic wild dogs biting one , a South American bush pawl performing “ flehmen ” ( a lip curl , followed by an inhalation ) , and a Siberian Panthera tigris toying with ( in this case , carrying ) the log . The tiger was the most persistent , while the South American bush dogs lost involvement over time .
" How this has educate through evolution is an interesting question,”Laska says . “ Perhaps there is a common denominator for all mammalian blood . " He design to come up with how prey animals like mice oppose to lineage odor .
persona : Linköping University ( top ) , 2014 Nilsson et al . , PLOS ONE ( middle )
