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Hermit crabs: The social animal that will help its peers come out of their shells (by force)

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You know what a hermit crab looks like. Those beady eyes just slightly sticking up from the shell of a snail make this critter one of the cutest animals you can find on the P.E.I. shoreline (move over, plovers).

But did you know that besides being the cutest, they’re also the coolest?

“These animals are super fascinating,” says Jeff Clements, an aquatic biologist with Fisheries and Oceans Canada and expert on all things fly under the sea. “There’s all kinds of other super cool behaviours that they do.”

Hermit crabs are members of a group of crabs known as pagurids — animals that live in the empty shells of snails.

 

Island Morning5:52Hermit Crabs on PEI

If you see one on the beach, there’s a good chance you go in the other direction. CBC found out all about hermit crabs..where you’ll find them and whether or not they can hurt you!

You can find hermit crabs in many different habitats, including sandy or muddy beaches and along rocky shores, especially those that have tide pools.

“They like to stay wet…. You may see them roaming around on the dry shore, but you’re more likely to find these if you’re walking ankle-deep in water,” Clements said.

They eat pretty much anything they can get their hands — er, claws — on. That includes detritus (the poop and bits of dead body parts from other organisms; see the lugworm), plants and other animals.

“Because they’re so versatile, hermit crabs can actively predate on some animals if they can manage to capture and kill them,” Clements said.

“You’ll often find them scavenging on the carcasses of dead animals that are floating around on the bottom of the sediment there, such as crabs, and they’ll eat the bits of dead plants and animals that are floating about.”

If you come across one, you’re also likely running into a hundred of so of its best friends. Hermit crabs are pretty sociable creatures, with complex mating rituals and other social behaviours that make the animals “pretty neat,” in the words of our aquatic biologist.

So let’s talk about shells.

Are you seriously wearing that?

You can find three types of hermit crabs on P.E.I. beaches: the Acadian hermit crab, the hairy hermit crab, and the long-wristed hermit crab. They’re often found in periwinkle or moon snail shells, but they can live in many different types.

Clements said these species are difficult to tell apart, with only a few distinguishing features on their heads and claws.

 

Kingdom of the Tide: Hermit Crab

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Finding shelter can be difficult for the hermit crab, and sometimes it can be a downright battle!

But that doesn’t mean they’re all the same, for hermit crabs are also unwavering stylists.

“There’s always going to be hermit crabs that are in shells that they don’t like — one that’s a bit too small, one that’s a bit too big,” Clements said. “If a hermit crab comes across an empty shell, it’ll assess it by looking at it and feeling it, and if it likes that shell more than the one that it’s in, it’ll trade up.

Why do they do this? These fickle fashionistas will never be caught dead sporting a shell that’s loose-fitting, or one that’s too revealing.

“If the shell is too big, it’s heavy and it takes a lot of energy to move it around,” Clements said. “If it’s too small, it can be hard to fit into, and it can leave soft parts of the body exposed and vulnerable.”

Sometimes hermit crabs perform this clothes swap — house swap? — in pairs, Clements said. When one crab finds a bigger shell, it can give its old shell to a friend as a hand-me-down.

Jeff Clements is an aquatic biologist with Fisheries and Oceans Canada. He’s based in Moncton, N.B. (Submitted by Jeff Clements)

“[The shells] create in some situations… a kind of chain reaction within the social group,” he said.

Other times, the switch is not that amicable.

Getting crabby

In hermit crab world, shells are such a prized commodity that they’re worth fighting to the death for.

Well, maybe not to the death. But it’s still pretty violent by hermit crab standards.

“If [a hermit crab] sees a shell that another hermit crab has, but it wants that shell, it will go over and basically knock on that shell really hard with its claws to try and get the hermit crab that’s in the shell it wants out, so it can basically steal its home,” Clements said.

Hermit crabs fight hard and often. Not just for shells, but also for other limited resources such as food and mates.

With all this competition, they have to be clever and pick their fights.

Because their body is hidden from view by their shells, hermit crabs have to gauge the size of their opponent by looking at their claws.

Common hermit crab (Pagurus bernhardus) foraging on the sea floor. (Sven-Erik Arndt/Arterra/Universal Images Group/Getty Images)

Clements said some of the smaller hermit crabs actually spend energy making their claws bigger to trick their opponent into thinking they’re big and scary. (Sure.)

And if they’re putting so much care into their outfit, why not accessorize?

“Sometimes, they’ll decorate their shelves with algae or sea anemones to camouflage or add protection.”

Be nice now

Hermit crabs, like most of the animals CBC P.E.I. has profiled on our Beach Finds series this summer, are threatened by climate change.

“They’re cold-blooded animals, which means that the temperature of their body internally is dependent on the temperature of the body outside,” Clements said. “There’s evidence that increasing temperatures can affect their physiology, and so as ocean temperatures get warmer, there’s some concern that effects may happen there.”

Because of their shell-based social behaviours, ocean acidification — which makes it hard for animals like moon snails to keep their shells — may also impact the little critters, Clements said.

This is one potential reason why we might want to leave shells on the beach. We might want to leave those resources for the hermit crabs rather than putting them on a kitchen table.— Jeff Clements

So, if you see a hermit crab, be kind.

“Hermit crabs generally are pretty harmless. If you pick them up, they’re going to retract into their shell and hide for the most part,” Clements said, though he added others may indeed try to pinch you.

“As I mentioned, shells are really, really important to hermit crabs…. This is one potential reason why we might want to leave shells on the beach. We might want to leave those resources for the hermit crabs rather than putting them on a kitchen table.”

 

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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