For baby eared seal ( or otariids ) , being able-bodied to recognize mom in a huge crowd is full of life for survival . distaff sea lions and fur seals only nurse their own pups , and they ’re very belligerent towards those who are n’t refer to them . Researchers studying vocal credit in south-polar fur SEAL ( genus Arctocephalus genus Gazella ) in the southern Indian Ocean have revealed that it ’s a two - step process : whelp identify their moms using different constituent of her outspoken signature tune at longer distances than they do at closer range . The finding are published inPLOS ONEthis week .
When Antarctic pelt seals come ashore to cover , it ’s in dense colony of several hundred duo of mother and pup . During the four - month lactation menstruation , mothers alternate between give suck on realm and foraging at sea . When a distaff returns , sometimes up to seven days later , she and her waiting pup call out to find each other , and then employ smell as a final check . This vocal designation process needs to be incredibly efficient , otherwise females permissive waste energy and pup risk wound .
A leash led byThierry Aubinfrom Université Paris - Sud wanted to study the unlike components of vocal signatures that pups discover and then use them to identify their mother on Kerguelen Archipelago at Cape Noir in the Courbet Peninsula in January and February 2000 during a lactation menstruum . The team recorded pup attracter calls produced by 32 female person who were locating their pups , and then carried out playback experiments with 29 wild pups using synthesized calls and playbacks at unlike distance .
Pups use modulations in both amplitude and absolute frequency to identify their female parent ’s voice . bounty is the size of it of the sound vibrations ( loudness ) , while frequency is the speed ( pitch ) . Frequency modulation propagated dependably up to64 meters(210 feet ) , and bountifulness pitch contour degrade after eight meter ( 26 infantry ) .
The findings advise that the ma - pup recognition unconscious process has two step : one over long distances , the next at closer range . This individual vocal realization organisation developed by Antarctic fur seals , the authors write , is well adapted to face up the main constraint of finding kin in a crowd .
Male Antarctic fur seal is call . Pierre Jouventin
