ocean otters use rocks to break open shells and get to the undecomposed stuff inside , the only maritime mammals to frequently do this . Scientists have shown the typical wear produced by generations of otter can be used to track where they once survive , and to search cultural deviation among otter populations .
The sea otter once inhabited northern Pacific coastlines from Mexico to Japan , but hunting for pelt reduce them to minor patches . With few fossils and little reporting , we do n’t know much about their preceding density and influence on their home ground .
ocean otters are so proficient with stones some have even involve tojuggling . The Max Plank Institute ’s Dr Natalie Uomini realized we could utilize their frequent tool usage to dog their past times . InScientific Reports , she shows how their stonework leaves traces that can be key from other lifelike , or human , phenomenon , under the reminiscent title “ Wild Sea Otter Mussel Pounding Leaves Archaeological Traces ” .
Otters utilize stones to pry abalone off rock-and-roll and as “ pectus anvils ” to break scale while floating on their back in the water system . For archaeological purposes , however , their most interesting proficiency is what she calls “ emergent incus habit ” where mussel shells are bop against shore stone to break them open .
In a 10 - year report at Bennett Slough , California , Uomini found mussels , which make up one-half of the otter ' target , were mint against John Rock points or ridges while the otter was in the water , rather than follow onto land . The consistent angle wore the stones down in distinctive style , make it possible to recognise the otters ' favorite Stone . Tens of 1000 of mussel eggshell were left scattered around the favored rock ‘n’ roll . These usher a consistent pattern , with the two sides attached and a aslope fracture on the racing shell ’s right side , consistent with Uomini ’s observance the otter apply the mussels in both front paws , but with the good hand on top to apply the effect .
" The shell break patterns provide a new way to distinguish mussel broken by ocean otter pounding on emergent anvil from those broken by homo or other animals , " Uomini enounce in astatement . This can facilitate archaeologists studying human coastal fellowship avoid mistake the remains of otter natural process for those of humans .
To carbon monoxide - authorJessica Fujiiof the Monterey Bay Aquarium there are more exciting the States , however . “ Stationary anvil use can be detect in locations antecedently inhabited by ocean otters . This information could assist to document past sea otter presence and diet in locations where they are presently extirpate , " shesaid .
Ottersaren’t the only animalsto have enter the Stone Age . archeology has been implement to the tool of other great apes , but never before to an brute so distant from us . The authors go for analyze old otter detritus , and those of other prick users like crows , will help us translate how dick habituate develop , and research why some otter communities use stones more than others .
