At the bottom of Buffalo Ford Lake at Yellowstone National Park , researchers have discover interesting cue about the lifelike story of the sphere .
Before the 1800s CE , the American bison was thriving . Estimates of buffalo figure on the continent vary from around30 to 60 millionat the start of the C , but that quickly changed as European coloniser reached North America .
" During the 19th century , when European American settlement was spread out into the Great Plains , bison were consistently slaughtered to the brink of extinguishing , " the US Fish and Wildlife Serviceexplains . " By 1889 , only a few hundred wild plains bison remained in the Texas Panhandle , Colorado , Wyoming , Montana and the western Dakotas , as well as a small numeral in captive herds . "
Not much is bonk about bison in the area before their numbers began to dramaticallydeclineas European settlers took away their natural home ground for farming , and hunted them for their hides and meat . In the new study , researchers led by John Wendt of Oklahoma State University appear at the sediment of a lake inYellowstone National Parkfor answers .
The study first looked at the steroid hormone present in the droppings of large herbivores , including bison , moose , elk , mule deer , and pronghorn , and compare this to the steroid profile of the lakebed deposit .
" Molecular biomarkers preserve in lake deposit are increasingly used to develop records of preceding organism occurrent , " the team explained in their paper . " When linked with traditional paleoecological methods , analysis of molecular biomarkers can render new insight into the theatrical role of herbivores and other animate being in foresightful - full term ecosystem dynamics . "
Based on their muck alone , the team found that they could identify moose , pronghorn , and mule deer well , but elk and bison were hard to specialise from each other . Nevertheless , they found thatbison , elk , or a combining of the two were the dominant herbivore in the Buffalo Ford Lake area over the retiring 2,300 years .
" The Buffalo Ford Lake record provide authoritative setting for translate ungulate occupancy of a watershed that is consistent with regional records of their management and seasonal shape of use , " the squad write in their conclusions .
" Specifically , our results channelise to two millennia of continuous bearing of bison and/or elk and exceptionally high impacts by these ungulate in the 20th century when hunting was banned , predator were suppressed , winter forage was affix with hay , and reach expansions were actively discouraged . "
Further work is needed to see how much changes to local ecosystems impact fecal steroid levels , but the squad says that this study shows that fecal steroid analysis of lake sediment can be used to reconstruct animal presence over time .
" We develop a 2,300 - twelvemonth record book of uncivilized herbivore bodily function in northern Yellowstone National Park with fossil biomarkers ground in lake sediments , " the squad explained in astatement . " This information is vital for understanding long - term dynamic of ecologically and culturally significant herbivores such as bison and elk . "
The field is print inPLOS ONE .
