Page 28 - ARUBA TODAY

A28 SCIENCE
Monday 19 February 2018
What does a bear do in the Alaska woods? Disperse seeds

ate plant being primar- ters deep, Levi said. If ro-
ily dispersed by mammals dents lose track of caches,
through their gut, Levi said. there's a chance for new
The finding suggests reper- plant growth.
cussions for plant life when It’s an intricate system start-
bears are removed. ing with salmon attract-
Brown bears, or grizzlies, ing bears, Levi said. Laura
flourish in size and numbers Gough, an ecologist at
in the Tongass National Towson University who has
Forest, America's larg- conducted research for
est, because they gorge more than 20 years on how
on spawning salmon. As plants interact with other
they wait for fish to enter organisms in Alaska’s tun-
streams, they eat berries. dra, said a lot of ecology
Levi and graduate student research focuses on uncov-
Laurie Harrer, the study's ering those relationships
primary author, set up mo- and how whole systems
tion-triggered video cam- change if they’re disrupt-
eras to detect what was ed. “When you think about
eating berries. The collect- that, if the species is an im-
ed bear DNA from saliva portant food source, then
left on plants after berries if that plant should diminish
disappeared. They record- in abundance, there could
ed birds picking off a few be a whole suite of chang-
In this October 2017 photo, a black bear walks in Granite Basin, amid low-lying blueberry thickets, berries at a time but bears es to that ecosystem,” she
in Juneau, Alaska. A study of bears and berries has determined that the big animals are the main gulping them by the hun- said. When she read the
dispersers of fruit seeds in southeast Alaska. The study by Oregon State University researchers says dreds. study, she said, she thought
it's the first instance of a temperate plant being primarily dispersed by mammals through their When brown bears shift of the dodo bird stories
excrement rather than by birds.
(AP Photo/Becky Bohrer) to eating fish, black bears she tells to students in bi-
move into berry patches. ology classes. The extinct
By DAN JOLING black bears, and not birds, fessor. "By planting seeds Both bears, through their birds spread seeds of cer-
ANCHORAGE, Alaska (AP) as commonly thought, are everywhere, they promote scat, disperse fruit seeds by tain plants. “When dodos
— Does a bear leave scat primary distributers of small a vegetation community the thousands, profoundly went extinct, those plants
in the woods? The answer is fruit seeds in southeast Alas- that feeds them." affecting what grows in basically went extinct as
obvious but the effects on ka, spreading the seeds Seed dispersal is a key the forest, according to the well,” she said. “So, this link
an ecosystem may not be. through their excrement. component in the under- researchers. Rodents that between animals that eat
A study by Oregon State "Bears are essentially like standing of any ecosystem, find bear scat further dis- plant seeds and disperses
University researchers con- farmers," said Taal Levi, an Levi said. The study is the perse seeds, burying them them — that can maintain
cludes that brown and Oregon State assistant pro- first instance of a temper- in caches a few millime- both populations.” q
Climate change diet: Arctic sea ice thins, so do polar bears

By SETH BORENSTEIN female white giants with days. catching seal pups even of Alberta biology profes-
MARK THIESSEN tracking collars that had "You're talking a pretty during prime hunting time, sor Andrew Derocher, who
ANCHORAGE, Alaska (AP) video cameras and the amazing amount of mass Pagano said. The United wasn't part of the study.
— Some polar bears in bear equivalent of a Fitbit to lose," said U.S. Geologi- States Fish and Wildlife Ser- The study found that on the
the Arctic are shedding during three recent springs. cal Survey wildlife biologist vice lists polar bears as a ice, the polar bears burn
pounds during the time The bears also had their Anthony Pagano, lead au- threatened species. up 60 percent more energy
they should be beefing up, blood monitored and were thor of a new study in Thurs- Polar bears hunt from the than previously thought,
a new study shows. It's the weighed. day's journal Science . ice. They often wait for seals based on these first real-
climate change diet and What the scientists found Researchers studied the to pop out of holes to get life measurements done
scientists say it's not good. is that five of the bears lost bears for 10 days in April, air and at other times they on the ice. A few of the
They blame global warm- weight and four of them when they are supposed swim after seals. If there is bears travelled more than
ing for the dwindling ice lost 2.9 to 5.5 pounds (1.3 to begin putting on weight less sea ice and it is broken 155 miles (250 kilometers) in
cover on the Arctic Ocean to 2.5 kilograms) per day. so they can later have apart, bears have to travel about 10 days off the north-
that bears need for hunting The average polar bear cubs, feed the cubs and more — often swimming — ern coast of Alaska in the
seals each spring. studied weighed about 386 survive through the harsh and that has serious conse- Beaufort Sea, Pagano said.
For their research, the sci- pounds (175 kilograms). winter. But because the quences, such as more en- The average bear female
entists spied on the polar One bear lost 51 pounds ice is shrinking, the bears ergy use, hypothermia and burned about 13,200 calo-
bears by equipping nine (23 kilograms) in just nine are having a harder time risk of death, said University ries a day — six times more
than an active human fe-
male.
"Just to break even they
have to capture at least
one seal every five to 10
days — and that's just to
break even," said study
co-author George Durner,
a USGS research zoolo-
gist. "And if they don't do
that they're going to lose
weight."q