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A28 SCIENCE
Monday 25 noveMber 2019
Study: Yellowstone bison mow, fertilize their own grass

MISSOULA, Mont. (AP) — A forced the plants to keep
study of grazing in Yellow- growing, giving the bison a
stone National Park found steady supply of fresh, nutri-
that bison essentially mow tious grass. "During most of
and fertilize their own food. May and June and part of
This allows them to graze in July ... they are grouped to-
one area for two to three gether repeatedly grazing
months during the spring the same area," Geremia
and summer while other said. Bison "are not just mov-
hoofed mammals must ing to find the best food;
keep migrating to higher they are creating the best
elevations to follow new food," said Jerod Merkle, a
plant growth. professor in migration ecol-
Hundreds of bison grazing ogy and conservation at
in an area stimulates the the University of Wyoming.
growth of nutritious grasses, "This happens because bi-
in part because their waste son are aggregate grazers
acts as a fertilizer, accord- that graze in groups of hun-
ing to research published dreds or more than a thou-
this week in the Proceed- sand animals."
ings of the National Acad- In this Aug. 3, 2016 file photo, a herd of bison grazes in the Lamar Valley of Yellowstone National While the effect of aggre-
Park in Wyo. In this Aug. 3, 2016 file photo, a herd of bison grazes in the Lamar Valley of Yellow-
emy of Sciences. stone National Park in Wyo. gate grazers was known
"They add fertilizer through Associated Press on a small scale, sensors on
urinating and defecating, NASA satellites can detect
they drop nutrients back on stayed greener and had a imal migration," Geremia not allowed to graze," said how grassland dynamics
the landscape, which are higher nutritional quality for said, "but they create good Matthew Kauffman, unit differ between areas that
then available to plants," a much longer time, Ger- food by how they move leader of the U.S. Geologi- are lightly or heavily grazed
Yellowstone scientist Chris emia said. and how they graze." cal Survey's Wyoming Co- by bison, the research
Geremia said Wednesday. Many other migratory From 2012 to 2017, re- operative Fish and Wildlife showed.
"It's almost like the bison animals in Yellowstone — searchers fenced off plots Research Unit at the Uni- "Our work shows that bison
become this giant fleet of pronghorn, bighorn sheep, of grass along bison migra- versity of Wyoming. "The are capable ecosystem
lawnmowers moving back mule deer and elk — do tion corridors and com- mowed-down forage had engineers, able to modify
and forth across the land- not form these large groups pared them to the grazed higher ratios of nitrogen to grasslands in a way that
scape," he said. while they migrate and areas. "The data showed carbon, a standard mea- enhances their own graz-
When more bison grazed graze, Geremia said. that grasses heavily grazed sure of nutritional quality." ing," said Mark Hebble-
an area more intensely, the "Bison don't just move to by bison were more pro- Trampling and nibbling by white, professor of ungu-
area greened up earlier find food, kind of the clas- ductive compared to ex- the bison kept the plants late habitat ecology at the
and faster and the grass sic way that we think of an- closures where bison were shorter and denser and University of Montana.q

Carcass of giant blue whale

brought to surface for study

NEWPORT, Ore. (AP) — The ber in 1806 when what The bones will be transport-
carcass of a giant blue is believed to be a blue ed to a nearby warehouse,
whale that's been sub- whale washed ashore and the university is asking
merged off the Oregon near modern-day Cannon for local volunteers who
coast for more than three Beach, Oregon. can help them remove oil
years was hauled to the Seeing an opportunity, sci- and fat from the bones,
surface so it can be reas- entists removed 58 tons of Mate said. The process of
sembled, studied and put flesh from the 2015 car- cleaning and reassembling
on public display, scientists cass and then placed the the giant whale will take
with Oregon State Univer- bones in the water off New- about a year, he added.
sity said Friday. The dead port, Oregon, so underwa- "We've got a bunch of work
whale, which was about as ter scavengers could pick to do to get everything
This Nov. 5, 2019 photo provided by Oregon State University long as two school buses, them clean. The bones cleaned up," Mate said. "It's
shows a 78-foot blue whale that washed ashore near Gold washed ashore near Gold were placed in huge critical to get the oil out of
Beach, Ore.
Associated Press Beach, Oregon, in 2015. nets and submerged with the bones to help preserve
It's exceptionally rare to weights in Yaquina Bay the skeleton and keep it
see an intact blue whale with the help of a technical from becoming rancid."
carcass wash ashore. The dive team from the Oregon Once reassembled, the
only other documented Coast Aquarium. skeleton will go on display
case happened more than All 365 of those bones were at the new marine studies
200 years ago, said Bruce brought back to land Thurs- building under construction
Mate, emeritus director of day, including 18-foot-long at the Hatfield Marine Sci-
Oregon State University's (5.5-meter-long) mandibles ence Center in Newport.
Marine Mammal Institute. and a skull weighing 6,500 Scientists in 2015 said it
That's when the Lewis and pounds (2,900 kilograms), wasn't clear why the whale
Clark expedition traded according to a statement had died, but it did appear
with a local tribe for blub- from the university. undernourished.q