Tag Archives: nature

Leopard Bests Crocodile

Leopard savaging a crocodile caught on camera:

A series of incredible pictures taken at a South African game reserve document the first known time that a leopard has taken on and defeated one of the fearsome reptiles. The photographs were taken by Hal Brindley, an American wildlife photographer, who was supposed to be taking pictures of hippos from his car in the Kruger National Park.

The giant cat raced out of cover provided by scrub and bushes to surprise the crocodile, which was swimming nearby. A terrible and bloody struggle ensued. Eventually, onlookers were amazed to see the leopard drag the crocodile from the water as the reptile fought back.

Eventually the big cat was able to sit on top of the reptile and suffocate it. In the past, there have been reports of crocodiles killing leopards, but this is believed to the first time that the reverse scenario has been observed.

Starved Rock State Park, Illinois

Photos from my hike in Starved Rock State Park, Illinois in 2006.

blue flower photos of red berries

Turtle Camps in Malaysia

Drawing of sea turtles

Pelf Nyok has posted drawing of turtle camps students that she taught in Malaysia. On the image shown on the left:

The third poster shows the threats that our turtles are facing — a turtle is trapped in a fisherman’s net, a turtle is consuming a plastic bag, which it mistakes as a jellyfish, and there are rubbish on the sea floor.

Pelf is on her way to the USA for turtle conservation training on the Asian Scholarship Program for in-situ Chelonian Conservation:

a 4-month scholarship, and involves professional training in the conservation of turtles (including sea turtles, freshwater turtles and tortoises, I presume). The flow of the program has yet to be finalized but according to the Director of the Program, we (the Laotian student and I) would be spending one month visiting turtle scientists and turtle research centers in New Jersey, Tennessee, Florida and maybe California.

And the remaining 3 months would be spent at the Wetlands Institute at Stone Harbor, New Jersey. The training will be conducted at the Wetlands Institute, together with other local participants.

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Mutualism – Inter-species Cooperation

Shrimp with Goby Fish

A Mutual Affair by Olivia Judson

I’d like to introduce you to one of my favorite animals: the shrimp goby. These pretty little fish lead lives of enviable indolence. As their name suggests, they live with shrimp (often, a pair). The shrimp build and maintain a burrow, which the goby and shrimp live in together. Each shrimp works hard, shoveling sand out of the front entrance like a miniature bulldozer. As soon as it’s delivered the rubble to a suitable distance, it shoots back into the burrow.

The front entrance of the burrow is often reinforced with bits of shell and coral — all of which is done by the shrimp. The goby just sits in the entrance of the burrow, keeping guard and warning the shrimp, which is nearly blind, of danger. At any sign of danger — a diver coming too close, a passing predator — the goby darts into the burrow. If the goby zooms in, the shrimp hastily retreats deep inside. And before the shrimp emerges from the burrow, it touches the goby’s tail with its long antennae. To show it’s safe to come out, the goby gently wiggles its tail. When the shrimp is out of the burrow, it keeps one antenna touching the goby. If the goby suddenly retreats, so does the shrimp.
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These animals are dependent on each other. Remove the fish, and the shrimp stops burrowing; the shrimp forage while burrowing, so without a fish, they grow more slowly, too. The shrimp need their guard goby. And the guard goby needs its shrimp: deny the goby shelter in a burrow, and it will promptly be killed by predators (yes, someone did the experiment). The shrimp keep the goby clean, too: they groom it.

photo by Boogies with Fish

Coopers Rock State Forest, West Virginia

photo of Coopers Rock State Forest in West Virginia

See more photos of my visit last year to Coopers Rock State Forest in West Virginia. The day before I visited Rocky Gap State Park in Maryland. Photos by John Hunter.

Appetite for Destruction

photo of Mountain Pine Beetle

Appetite for Destruction (link broken, so I removed it) by Eric R. Olson:

“Once the beetles are at the level they’re at in British Columbia, there’s nothing you can do – it’s like a rapidly spreading fire,” says Barbara Bentz, research entomologist with the U.S. Department of Agriculture Forest Service. If the beetle continues to devour trees at the current rate, 80 percent of British Columbia’s mature pines will be killed off by 2013, according to Natural Resources Canada, an arm of the Canadian government.

Global climate change, which is pushing temperatures higher, has altered the beetle’s natural life cycle. Now the insect threatens one of the world’s largest forest systems: Canada’s boreal forest, a 600-mile-wide band of pine woodlands that stretches from the Yukon in Alaska all the way to Newfoundland on the East Coast.
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The source of all this destruction is an insect not much bigger than a grain of rice. A native of North America, the pine beetle does its damage by burrowing beneath the bark and feeding on the living tissue of the tree called the phloem. This tissue is composed of long tubes that transport nutrients from root to limb, and once it is destroyed, the tree can no longer survive.

In the past, cold snaps — quick drops in temperature in the spring and fall — have kept beetle populations in check. Although the insects can survive temperatures as low as minus 35 degrees Fahrenheit in the winter, it takes time for their bodies to accumulate enough glycol, the same ingredient found in antifreeze, to survive such frigid temperatures.

Photo: Mountain Pine Beetle (Dendroctonus Ponderosae) under a scanning electron microscope. [Credit: Leslie Manning/Canadian Forest Service]

Baby Sand Dollars Clone Themselves When They Sense Danger

Baby sand dollars clone themselves when they sense danger

The odds of growing up aren’t good for baby sand dollars. Smaller than the head of a pin, the larvae drift in the ocean — easy prey for anything with a mouth.

But a University of Washington graduate student has discovered the tiny animal has a surprising survival strategy: Faced with the threat of being gobbled up, it makes like Dr. Evil from the Austin Powers movies and clones itself. The resulting “mini-me” may escape hungry fish because it is even teenier than the original — and harder to see.

“If you are eaten, but the smaller version of you survives, you’re still a winner from an evolutionary standpoint,” said Dawn Vaughn.
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Familiar inhabitants of Washington’s subtidal zone, sand dollars start life though the chance encounter of sperm and egg, simultaneously released into the water by mature adults. The larvae free-float for about six weeks before metamorphosing into miniature sand dollars that settle in colonies and eventually grow to full size.
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The white shells that wash up on the beach are the creatures’ external skeletons. Living sand dollars are covered with velvety, purple spines used to grab food particles. Vaughn knew many other marine invertebrates shift their shape to avoid being eaten. Colonial animals called bryozoans grow spikes when voracious sea slugs crawl across them. Barnacles take on a bent posture to repel snails. Vaughn’s own previous research showed periwinkle larvae narrow their shell openings to keep out marauding crab larvae.

Secret Life of Microbes

New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems

Nowhere is the principle of “strength in numbers” more apparent than in the collective power of microbes: despite their simplicity, these one-cell organisms–which number about 5 million trillion trillion strong (no, that is not a typo) on Earth–affect virtually every ecological process, from the decay of organic material to the production of oxygen.

But even though microbes essentially rule the Earth, scientists have never before been able to conduct comprehensive studies of microbes and their interactions with one another in their natural habitats.
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Because microbes are an ecosystem’s first-responders, by monitoring changes in an ecosystem’s microbial capabilities, scientists can detect ecological responses to stresses earlier than would otherwise be possible–even before such responses might be visibly apparent in plants or animals, Rohwer said.

Evidence that viruses–which are known to be ten times more abundant than even microbes–serve as gene banks for ecosystems. This evidence includes observations that viruses in the nine ecosystems carried large loads of DNA without using such DNA themselves. Rohwer believes that the viruses probably transfer such excess DNA to bacteria during infections, and thereby pass on “new genetic tricks” to their microbial hosts. The study also indicates that by transporting the DNA to new locations, viruses may serve as important agents in the evolution of microbes.

Grand Flood

Grand Canyon photo by John Hunter

Model analysis helps protect river’s ecosystem

The goal of the high-flow experiment, the third since 1996, is to see if such high flows can help reconstruct some of the canyon’s beaches and sand bars that are instrumental to ecological systems and native fishes that have suffered since the building of the Glen Canyon Dam in 1963.
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By allowing flow of water that, at its peak, will be more than three times its normal rate (to a volume of 41,500 cubic feet per second), researchers hope to flush some of the dam system of its backed-up sediment and reconstruct habitat downstream. It is expected that the high water-flows will rebuild eroded beaches downstream of the dam by moving sand accumulated in the riverbed onto sandbars.

That in turn will allow the re-establishment of eddy sandbars that provide the slow moving, backwater channels vital for native fish species. The sand bars also provide camping areas for river runners and hikers, and the beaches provide sand to the canyon that helps preserve archaeological resources.

Deep-Sea Denizen Inspires New Polymers

Stealing a trick from a tiny, pickle-shaped creature that dwells in the depths of the ocean, scientists have designed a new polymer that, when exposed to water, can instantly change its rigidity and strength.
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Christoph Weder, an associate professor in the same department at Case, says he and Rowan thought of copying the sea cucumber’s adaptation more than five years ago. Working with marine biologists, they determined that the deep-sea animal accomplished its transformation thanks to fibers made of a protein known as collagen. The tightness of the connections between those fibers determines how stiff the cucumber’s skin is, and is controlled by the animal’s nervous system.

To get their polymer to do the same thing, the Case scientists used fibers found in another deep sea dweller, sea squirts, and also in cotton. When they mixed those fibers – known as cellulose nanofibers – with the rubbery polymer ethylene oxide–epichlorohydrin, they formed a stiff network, “almost glued to each other,” says Weder. Due to the nature of the bonds between the polymer and the fibers, however, water gets between the two substances, weakening the fibers’ adhesion. The material then becomes soft.