As conversations of weather occurrences and suggested anomalies become more frequent and mainstream in the scientific community, as well as at the grass-roots-level, the need to embrace and index substantive information into an authoritative conduit to encourage more research and development~~~IS IMPERATIVE.
Pertinent themes as Global Warming, Climate Change, and Melting Ice Caps has stimulated discussions, seeded forums, and spawned additional research, all to foster consensus, and recommend courses-of-action.
The intent of CLIMATE; THE CONVERSATION, is to be The Bulletin Board, The Platform, The Podium, and The Credible Source & Bibliography for such astute, sincere, and scholarly considerations.
Sincerely;
Administrators:
Andrew M. Marconi
Lou Marconi
***********************LA
PÉROUSE BAY, Manitoba — The sea ice here on the western shore of Hudson
Bay breaks up each summer and leaves the polar bears swimming for
shore. The image of forlorn bears on small rafts of ice has become a
symbol of the dangers of climate change.
And
for good reason. A warming planet means less ice coverage of the Arctic
Sea, leaving the bears with less time and less ice for hunting seals.
They depend on seals for their survival.
But the polar bears here have discovered a new menu option. They eat snow geese.
Because
the ice is melting earlier, the bears come on shore earlier, and the
timing turns out to be fortunate for them. As a strange side-effect of
climate change, polar bears here now often arrive in the midst of a
large snow goose summer breeding ground before the geese have hatched
and fledged. And with 75,000 pairs of snow geese on the Cape Churchill
peninsula — the result of a continuing goose population explosion —
there is an abundant new supply of food for the bears.
What’s
good for the bears, however, has been devastating to the plants and the
landscape, with the geese turning large swaths of tundra into barren
mud. Nor does it mean that the bears are going to be O.K. in the long
run.
What
is clear is that this long-popular fall destination for polar bear
tourism has become a case study in how climate change collides with
other environmental changes at the local level and plays out in a blend
of domino effects, trade-offs and offsets.
“The system is a lot more complicated than anybody thought,” said Robert H. Rockwell, who runs the Hudson Bay Project, a decades-long effort to monitor the environment.
To
fully appreciate how the chain reaction plays out in La Pérouse Bay
requires studying the individual links in the chain — the geese, the
bears, and the plants and the land beneath them.
Dr.
Rockwell, 68, has been counting geese in this area every summer since
1969. In the late 1970s, he started building his current camp — a few
buildings surrounded by an electric bear fence. It is reachable by
helicopter only from nearby Churchill.
From
this vantage point, Dr. Rockwell and his team have witnessed the snow
goose population swell to the point where they are harming their own
nesting grounds. The number of snow geese that live and migrate in the
continent’s central flyway exploded from about 1.5 million in the ’60s
to about 15 million now, and many of them nest here or stop by on their
way farther north.
The
reason for the increase, Dr. Rockwell said, can be traced largely to
Louisiana and Texas, in the coastal marshes where the geese long spent
their winters feeding on spartina, also known as salt hay or salt meadow
cordgrass. They then migrate north in spring to nest and raise goslings
on grass and sedges and other plants in the marsh and tundra of the bay
shore.
The
goose population, Dr. Rockwell said, was once limited in size by its
sparse winter food supply in southern states. After many of the marshes
were drained for various kinds of development, “the snow geese just sort
of said, well, wait a minute, what was that green stuff just north of
here? And it turns out those are the rice prairies,” he said.
Having
found the rice farther north in Louisiana, the geese continued to
explore and expand their winter range, finding the vast agricultural
fields of the Midwest. “So a species that was once in part limited by
winter habitat now has an infinite winter supply of food, and that
includes the best agricultural products: corn, wheat, soybeans, canola,
rapeseed, all of that,” Dr. Rockwell said.
Some
snow geese now winter in Nebraska and Iowa where these crops are grown.
But they keep coming to the sub-Arctic and the Arctic in the summer,
following ancient habit. During Dr. Rockwell’s time here, the colony
increased from 2,500 pairs to 75,000, and the birds moved as far as 20
miles inland as they ruined areas near the coast because of their eating
habits.
Standing
near the shore of Hudson Bay last June after a long, wet hike through
bog and mire and stream and willow thicket, Dr. Rockwell surveyed the
damage done by geese: acres of muddy, barren terrain — save for the
bleached backbone of a bearded seal — all but devoid of vegetation.
Distant booming signals that the pack ice offshore is starting to break
up.
The
muddy ground used to be like a lawn — “golf course quality,” he said.
It is the area where the geese raised their broods after hatching.
Snow
geese graze, eating the tops of plants, and grub, pulling out plants by
the roots. They have a serrated beak and a powerful neck, which means
they are better able to grip and rip than their Canada geese cousins.
But
geese not only eat. They are eaten. Many creatures love the eggs and
goslings in particular — arctic foxes, sandhill cranes, gulls and, as it
happens, polar bears.
The Early Bear Gets the Bird
The
conventional view is that over all, polar bears are “food-deprived” in
the summer because there is just not enough food on land to make a
significant contribution to their diet. But the snow geese may have
changed that, at least here.
By
2007, it was clear that the sea ice was melting earlier, on average,
and the polar bears were often coming on shore in time to harvest the
eggs from vast numbers of geese and other birds.
Dr.
Rockwell, a researcher at the American Museum of Natural History, and
Linda Gormezano, a graduate student he was supervising, decided to go
beyond the sightings of bears eating geese and eggs. They approached the
bear diet question in a scientific way.
Dr.
Gormezano, who this fall began postdoctoral research at the University
of Montana, specializes in noninvasive methods for monitoring the
behavior of predators. In terms of diet, scientists can observe what
goes in, or what goes out. With an animal like a polar bear, the second
approach is more practical. They turned to polar bear feces, or scat, as
it is commonly called.
Dr. Gormezano trained a Dutch shepherd named Quinoa to find polar bear scat
and drove him north for several field seasons. She and Quinoa worked
with Dr. Rockwell to collect and study samples of polar bear scat for
several years and found that the bears were eating lots of geese. They
were also eating caribou and other animals, as well as berries —
anything in reach.
David
Iles, a graduate student at Utah State University, who has been working
at La Pérouse Bay for several years, set out cameras to observe goose
nests and caught the bears in the act. He now has 40 cameras set up over
a stretch of tundra. They take photographs every two minutes and shoot a
burst of 30 images when an animal walks in front of the camera.
In
addition to capturing photographs of bears consuming eggs last season,
the cameras caught cranes, wolves, eagles and foxes eating. “Everything
seems to love eggs out here,” he said.
One
goose or one nest may not seem like much. But polar bears are gluttons.
Dr, Rockwell described one case in which a bear ate about 1,200 eggs —
of eider ducks, in this case — in four days. He said Dr. Gormezano had
calculated that a clutch of four eggs would amount to 825 calories, the
equivalent of one and a half Big Macs. Three hundred four-egg clutches
would be 247,500 calories, or about 10 percent of a bear’s yearly
nutritional needs.
Dr. Rockwell and Dr. Gormezano have published several papers on their findings.
Some other polar bear researchers reacted with dismay about how the results may be interpreted.
Steven C. Amstrup, the chief scientist of Polar Bears International,
says he does not doubt that bears eat geese but questions how important
that fact is. He said he worried that these findings would be taken by
the public to mean that polar bears were doing fine.
“What
they have established,” he said of Dr. Rockwell’s work, “is that some
bears are eating some goose eggs and even geese. The important question
is how many bears are doing that and what is the impact.” Studies, he
said, have shown the condition of polar bears in the Western Hudson Bay
is deteriorating, whatever their diet.
He
added, “There is the potential for some number of polar bears to offset
some of their nutritional losses by taking advantage of goose eggs.”
But, he said, “It’s not reasonable to expect there’s going to be some
great salvation of polar bears.”
Besides,
he said, the concern for the bears is long-term and global. In the
future, as sea ice declines, “There’s no evidence that anything like
current polar bear populations can be supported,” he said.
Setting
aside for a moment what the bears’ eating eggs ultimately means for the
bears, Dr. Rockwell said their eating habits would not put a real dent
in the goose population, as he once hoped.
For
the geese population to remain constant, a pair of geese needs to have
only two surviving offspring in a lifetime of breeding. Snow geese have
many chances, typically with five or six seasons of four or five eggs
each. Those are good odds for maintaining a stable population.
And
that puts the plants of the tundra in an uncomfortable place, between a
goose and a warming trend. What that is doing to plants is what
scientists at the Hudson Bay project are studying next.
The Tangled Tundra
The
geese, birds, caribou and many other animals here live on plants. Those
plants are facing the goose onslaught, an increase in the caribou
population and swings in temperature that accompany the changing
climate.
Although
the tundra and marsh may look uniform and dull at first, a closer
inspection shows a rich and diverse miniature forest of grasses, sedges,
wildflowers, crowberries, cranberries, blueberries, cloudberries and
gooseberries.
Researchers
like Christa Mulder, a plant ecologist, from the University of Alaska,
Fairbanks, are studying what the plants are doing to better understand
how the whole ecosystem is faring. In one project, she is tagging 40
species to see how the timing of their growth is changing.
She
emphasizes that although climate change brings an overall warming
trend, it also is bringing increased variation in average temperatures,
and the timing of the seasons.
“In
some years, summer season starts very late,” she said. “Some years, it
starts very early. Sometimes, the fall comes very late. Sometimes, the
fall comes very early.”
And, she says, “A cold year slams plants down much harder than a warm year advances them.”
One
aspect Dr. Mulder is studying is how the plants deal with this
increased variability. It may be, she said, that for some plants, growth
may ultimately be delayed rather than advanced because of the effect of
the colder years.
One advantage Dr. Mulder has in her studies is a rich historical database.
As
early as the 1700s, people associated with the Hudson Bay Company were
recording the weather. By the 1930s, Churchill was connected to the
south by train, and amateur and professional botanists began taking
samples of plants, some of which are preserved in museum collections.
And,
in the 1970s, Robert Jefferies, Dr. Rockwell’s longtime collaborator at
La Pérouse Bay, was collecting plants as well. Dr. Mulder can follow
the plants’ growth patterns over nearly a century, and for years to
come.
That
future research in La Pérouse Bay is needed, Dr. Rockwell said, because
the current knowledge of how this ecosystem fits together — and how it
is evolving because of climate change — is so incomplete.
“You
get all these nonlinear kinds of things, which make it very hard to
understand,” he said. “But it makes it more fun to study.”*************
Its impact on the economy, pollution, and the focus on Climate; The Conversation---makes this worthy of continued enthusiasm and consideration
Lou Marconi (SuiteLou0819)
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