United States nature

Articles in ‘United States nature’

How does a Cobra lily trap its prey?

March 4th, 2011

In a sun-lit meadow on the mountainside, a large grove of curving plants grow close together in the marshy grass, which glistens with cool running spring water.  Humans are struck by the resemblance of these pitcher plants to hooded cobras, poised to strike, and have christened them Cobra Lilies, but for an insect there is nothing threatening about them at all.

On the contrary, they are very enticing.  The pitcher plant surface is covered in scattered nectar glands where insects can feed, and there are even more on a bright red appendage, forked like a snake’s tongue. The tongue hangs down from a mouth-like opening, and just inside there is a particularly copious supply of the tempting sweet stuff.

For us, the snake illusion is completed by the pattern on the domed leaves, giving the impression of scales.  They are translucent aeroles that flood the pitcher with bright light. An insect might be reluctant to enter a dark interior, but is lulled into a false sense of security in this well-lit space.

Having gorged, rather than go back out the way it came in, the insect might head straight for one of these false exits.  After all, the mouth is half hidden by its curling lip.

Disorientated and tired, like a fly that has been helplessly crashing into a glass window, the insect might try to settle on the slippery walls of the plant.  Unable to get a grip, it goes plunging down the spiralling tube straight into the pool at the bottom, which is kept filled with water pumped up from the ground.  The down-pointing hairs on the inner walls discourage any attempts of a soaked insect to climb back to freedom.  By the end of the summer, these carnivorous pitcher plants will be half-filled with insect remains, the sign of a successful season.

Cobra Lilies (Darlingtonia californica) are native to northern California and southern Oregon in the United States.

Scott Linstead’s high-speed photographs

July 22nd, 2010

http://fineartamerica.com/images-medium/leaping-roadrunner-scott-linstead.jpg

Remarkable high-speed photographs by Scott Linstead, using fast shutter speeds and special flash gear to capture his unique images of wildlifeIn the photo a Leaping Roadrunner from here.

The world’s fastest disappearing land mass

September 21st, 2009 Over the last four years, some 500 kilometres of wetlands around New Orleans have been lost to the sea, leading some biologists to call these wetlands “the fastest disappearing land mass on the planet”. Much of the area has been lost due to hurricanes Rita and Katrina. More here

Mass death of walruses

September 19th, 2009
Walruses por flickkerphotos.

As many as two hundred dead walruses have been spotted on the shore of Chukchi Sea on Alaska’s northwest coast. Wildlife researchers from the U.S. Geological Survey report the dead walruses appeared to be mostly new calves or yearlings. They may have been crushed in a panic stampede triggered by a polar bear or a helicopter. Large numbers of walruses are gathering on Alaska’s northwest coast, a sign their Arctic sea ice environment has been altered by climate change, the second time in three years that this has happened. They cannot swim indefinitely and until recently used sea ice as a platform for diving in the Bering and Chukchi seas for clams and other food on the ocean floor. Now, sea ice has receded far beyond the outer continental shelf, forcing walruses to choose between riding the ice over waters too deep to reach clams or onto shore. More here

Meanwhile, Sea ice cover in the Arctic Ocean reached the third lowest level on record last year, according to the latest NASA statistics. Here

Photo by Thundafunda

Grizzly Bears feeding at Brooks Falls

August 23rd, 2009
Brooks Falls 2 por Rhonda2327.

Grizzly Bears feeding at Brooks Falls in the Katmai National Park, Alaska. At times dozens of bears can be seen gorging on the sockeye salmon swimming upstream on their way to their spawning grounds. Photo by Brian Ronda (CCL). See also this rather amusing video:
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North American wildlife news 2

August 20th, 2009

Desert tortoise by Tigerhawkvok

Differences between grizzily and black bears

August 7th, 2009 You might think that black bears are black, and grizzly bears are easily to distinguish by their colour. But both bear species in Yellowstone can be black, brown, or even blonde. Another cliche is that black bears are much smaller than grizzlies, but although grizzlies are generally bigger, a big male black bear can easily outweigh a female grizzly or a young grizzly. Without colour or size as a guide, you have to look at other features. The best way to tell grizzlies and black bears apart at a distance is by their body shape. Unlike black bears, grizzlies have a distinct hump on their shoulders that is higher than their rump. Watch this video to learn more. Or read here.

North American wildlife news 1

August 7th, 2009

A grizzly bear standing in sage brush.

Photo: NPS/Peaco

A quick round of the latest news affecting wildlife and nature in North America. I picked up the idea from this site.

  • Climate change could result in the catastrophic loss of wildlife in US’s National Parks.  Service is called on to create a system to manage animals and plants. A new report calls on federal government to take decisive action to avoid “a potentially catastrophic loss of animal and plant life” in national parks” LA Times See also Yellowstone’s grizzly bears and other wildlife at risk from climate change “In Yellowstone, a tiny beetle may decide the fate of the kingly grizzly bear. Whitebark pine nuts provide a valuable food source for the bears. A beetle that destroys the whitebark pine tree has gained a considerable foothold in Yellowstone because of the effects of climate change. In some parts of the Greater Yellowstone ecosystem, beetles have destroyed up to 90 percent of the trees in whitebark pine forests. Removing this important component of the grizzly bears’ diet puts considerable stress on the species that could ultimately lead to extinction.”
  • A report by the US geological survey indicates a steep rise in the melt rate of American glaciers over the last 10-15 years. The study looks at three “benchmark” glaciers- Wolverine and Gulkana in Alaska and South Cascade in Washington – as representative of thousands of other glaciers in North America. The Guardian
  • Scientists In Alaska spot a bar-tailed godwit tagged in Australia near Victoria – more than 8,000 miles away.
  • Pollution is icreasing in US beaches according to this article.
  • A coalition of environmental groups is attempting to intervene in a lawsuit from snowmobilers challenging critical habitat designations for the Canada lynx. Here
  • King salmon runs in Alaska have been closed this year as fewer fish have returned from the ocean. The decline could be down to changes in river conditions, ocean currents or the predator-prey balance.
  • More bobcats sighted in Seattle area First it was bears, now it’s bobcats that seem to be popping up in Western Washington urban areas.
  • Coyotes struggle as mange spreads “Every night it used to be quite a serenade,Rocky Hoffmann at the Nebraska Game and Parks office in North Platte said. But we’ve had a tremendous mange problem throughout the state, and the numbers are down”
  • Sea Otter Population Rebounds in US Northwest The population began to recover in 1969, with a couple dozen survivors from a reintroduction effort. Today, there are well over 1,000 sea otters in the Pacific waters off Oregon, Washington and British Columbia.
  • Rare wolverine spotted in the Pioneers

More wildfires for the US

July 29th, 2009

Scientists expect wildfires in the US to increase in number as global warming kicks in in the coming decades. And because smoke and other particles from fires adversely affect air quality, an increase in wildfires could have large impacts on human health. Eureka

Wild mustang problem

July 27th, 2009

That most potent symbol of the American West, the horse, was introduced from Iberia and like other non-native species, can cause seriuos environmental harm. Read the rest of this entry