24 Mar 2017

The Undead of Winter

 By Jan Thornhill
Ruby LOVES to "play dead" so we can will bury her in snow!
I love early spring! And no – I’m not talking about tulips and the return of migratory birds, though I have nothing against those things. I’m talking about earlier, in the first weeks of March, when there’s still plenty of snow on the ground, when, for all intents and purposes, it’s still the dead of winter.

Except it’s not dead.



Minute snow fleas appear on warm days in late winter.
In fact, there’s a surprising amount of life in the late winter forest here in Ontario – especially when the temperature squeaks a few degrees above the freezing mark. By early March, tree sap has begun to flow. Within a few days, deciduous crowns in the distance have taken on a haze, as if someone has smeared wet watercolour across the tips of their sharp branches. Their leaf buds are plumping. Male chickadees start using their “Hey, sweetie,” song, which, I think, is self-explanatory. Skunks wake from their winter torpor and amble about briefly – possibly just to stretch their legs – before returning to their dens to wait for real spring to come. On sun-warmed snow patches at the base of trees, snow fleas congregate, sometimes by the tens of thousands (see my post about snow fleas here).


This perennial Red-belted Polypore (Fomitopsis pinicola)
will drop spores on warm winter days.
And, all over the forest—believe it or not—fungi are procreating like crazy.


Amanita frostiana has a mycorrhizal relationship
with oaks and conifers.
These are not your basic ground mushrooms with caps and stems that you see in summer and fall. Most of those are mycorrhizal, and have a mutualistic relationship with trees, trading underground water and nutrients for the sugars that trees produce. But trees shut down sugar production in the late fall, so the underground networks of mycelia of mycorrhizal fungi also shut down during the frozen months.


The Violet-toothed polypore (Trichaptum biforme) is an annual saprobe.
But there are all kinds of other fungi that have a different kind of relationship to trees. They rot them. Many of these tree decayers, or saprobes, are polypores. Polypores develop their spores inside tiny tubes instead of on gills like store-bought mushrooms. 


The Hexagonal-pored Polypore (Neofavolus alveolaris)
 
has—surprise!—hexagonal pores.
The most commonly noticed polypores are shelf fungi or conks. Many are perennial – they have skeletal hyphae—tissue than can withstand freezing and thawing—and just keep growing and growing, sometimes for 70 years or more. And during that time, whenever the temperature goes above freezing for a couple of days, these fungi produce spores. 


Yearly growth layers are obvious on this Phellinus that grows
new spore-producing tubes on its underside each year. 
But, why, you might wonder would they send out spores so much earlier than the birds start doing it and the bees start doing it—when the forest is still, in effect, asleep?
The Gilled Polypore, Lenzites betulina, has elongated tubes that almost look like gills.
They do it early because polypores, like all fungi, are opportunistic. Polypores that grow on living trees usually inhabit the heartwood that runs up the core of a tree trunk. To set up shop in this deadwood, a polypore has to get past a tree’s sapwood, the living layer below the tree’s bark. In the winter, deep freezes cause fractures in tree bark. These frost cracks are perfect for catching passing spores. When spring rains moisten the crevices, and before the tree has time to seal these cracks, the spores germinate and their mycelia work their way into the core. Once past the tree's defences, the fungus sets up shop, spreading its mycelia up and down and around. A fungus can secretly live inside a tree—gradually breaking down lignin and cellulose—for many years before it gives us humans a clue of its presence—by producing reproductive organs (shelf fungi, or conks) on the tree’s exterior.

Fomes fomentarius, is commonly called the Hoof Fungus
 (its shape)  or Tinder Fungus (used to carry fire from place to place
before matches were invented; Ötzi was carrying some).
The Cinnabar Polypore (Pycnoporus cinnabarinus) is the colour of dragon's blood!
The common name for Trametes versicolor is Turkey tails—for good reason
Chicken-of-the-Woods is an excellent edible polypore
 that has the unmistakable texture of overcooked
chicken if you miss its succulent stage.
This Artist's Conk (Ganoderma applanatum) is exhibiting geotropism
— the fungus first grew while the tree was still standing, then, after the tree 

fell, added new growth with its pore surface—once again—facing down.



20 Mar 2017

Explore Under the Sea, Live and Online

By Claire Eamer

From the website of the research ship, Okeanos Explorer: "From March 7 – 29, 2017, NOAA and partners will conduct a telepresence-enabled ocean exploration expedition on NOAA Ship Okeanos Explorer to collect critical baseline information about unknown and poorly known deepwater areas in the Howland and Baker Unit of the Pacific Remote Islands Marine National Monument and the Phoenix Islands Protected Area.

NOTE: ROV dives are planned, weather permitting, most days from March 8 - March 27, typically from about 8 am to 5 pm WST (March 7 - March 26, from 2 pm to 11 pm EDT)."

If you go to the dive website, you can watch the whole of the dive, seeing just what the scientists are seeing, and you hear scientists discussing what they are observing in real time. Warning: it's addictive!

A seastar is wrapped around the branches of a coral, hundreds of metres beneath
the surface of the Pacific Ocean. Screen capture from Okeanos Explorer feed.

17 Mar 2017

In Honour of Saint Patrick's Day - SNAKES!

By Claire Eamer

This day, March 17, is St. Patrick's Day, celebrated around the world by the Irish, the formerly Irish, the wannabe-Irish, and beer drinkers of all persuasions. It's generally marked by a lot of green - green clothing, green-dyed flowers, green-dominated parades, and that abomination - green beer.

But no snakes. Snakes almost certainly don't celebrate St. Patrick's Day (even though many of them are noticeably and naturally green). After all, St. Patrick is famous for driving the snakes out of Ireland. But did he?

A green tree python relaxes in comfort, using its own
body as furniture.
Sadly for legend, Ireland was snake-deprived long before St. Patrick arrived more than 1500 years ago. The cold temperatures and ice sheets of the last major glaciation drove snakes and other reptiles south. When the world warmed up about 10,000 years ago and the snakes moved back north, they were blocked by the cold waters of the Irish Sea. The few snakes that made it that far north simply settled down among the forests and hills of Britain and left the island of Ireland alone.

The Irish probably don't regret the lack of snakes, but they might be missing something. Snakes are amazing and quite beautiful. A few years ago, I wrote a book about animals adapting to extreme habitats (Lizards in the Sky: Animals Where You Least Expect Them) - and one of my favourite examples was the flying snakes of Southeast Asia.

The elegant rainbow boa is popular among collectors.
"Flying snakes?!?" you ask. (Well, most people ask that.) Really and truly! A small group of snakes in the jungles of Malaysia and Borneo has developed the ability to glide through the air. They fling themselves from a high branch, flatten out their bodies, and swim through the air in a wriggly glide. The most accomplished species, the paradise tree snake, has been seen to glide more than 20 metres - far enough to take it safely over a five-lane highway with room to spare.

And then there are the swimming snakes. "No, no... not swimming snakes too!" you cry. (I'm sure I heard you cry that.) Yup. Sea snakes, in fact.

Snakes taste tiny bits of scent in the air with their
tongues. The two forks of the tongue give the snake
a sort of stereo smelling capacity so it can tell
which direction the smell comes from.
Actually, sea snakes are quite common in the warm waters of the Indian and Pacific oceans, but most of them stay in the shallows close to shore.

The exception is the yellow-bellied sea snake, which is born at sea and lives there its entire life. Coolest fact? The yellow-bellied sea snake can tie itself in a knot. It loops around itself into a simple knot and runs the loop from one end of its body to the other to scrape off parasites and dead scales.

See what you're missing, Ireland?

Claire Eamer likes strange animals and weird facts and science of almost any kind. Her latest book is What a Waste! Where Does Garbage Go? (Annick Press, 2017).

10 Mar 2017

StripeSpotter: A Barcode Scanner for Zebras

by L. E. Carmichael

You've probably heard about scientists using photos of whale flukes to identify individual humpbacks. Did you know that a similar strategy is being used to count and identify zebras? Originally called StripeSpotter, it's a barcode scanner. A barcode scanner for zebras.
I'm going to pause to let that sink in, because the mental image is just hilarious and I would hate to deny you some Friday giggles. :D
Basically how it works is, scientists take a photo of the zebras. They feed the photo into StripeSpotter, and the computer finds unique characteristics in the stripe pattern of the zebra's coat. Any time that zebra is photographed again, it can then be checked against the database and identified.
This is supercool, because, unlike supermarket barcode scanners, where you have to hold the package at just the right angle while doing a little dance for the scanner gods, StripeSpotter works on "noisy" pictures. The kind that you're likely to get when shooting long-distance photos of a whole herd of zebras while riding a bouncy jeep across a dusty savanna. StripeSpotter also works on spotty animals, like giraffes, so it's flexible too.
Why does this matter, you ask? There are lots of reasons scientists need to know which animal they're looking at. For one thing, being able to identify individual animals makes it possible to count them. Counting helps scientists figure out whether a population is growing or shrinking, and, by extension, whether the species is endangered. It's also really helpful to know what individual animals are doing out there in the wild - whether they migrate or stay put, what they're eating, whether they are reproducing... the possibilities are both important and endless.
For more info on the technology and what it's being used for, click here. And for more info on zebras, check out Zebra Migration, for ages 6-9!

26 Feb 2017

Margriet Ruurs on the Galapagos Islands

By Claire Eamer

Our buddy and occasional Sci/Why blogger, Margriet Ruurs and her husband Kees have just completed an amazing trip to the Galapagos Islands, famed for the role they played in Darwin's understanding of evolution. Margriet is blogging about the experience - with beautiful photographs - on their Globetrotting Grandparents site, and I highly recommend following the series of posts. She has promised to write a post for Sci/Why eventually, but in the meanwhile you can enjoy her adventure - currently featuring blue-footed boobies and magnificent frigate birds.

19 Feb 2017

Living or Non-Living, There Is No Once-Living

As educators, we pay close attention to common misconceptions of our students and readers, and are prepared to correct them. Being human, we ourselves are equally susceptible to misconceptions and errors of logic. This particular one has popped up from more than one source, so I’m going to explain it here.

Readability is very important to educators, and particularly to children’s writers. We try to use vocabulary that students won't get stuck on, preventing them from concentrating on the concepts that are being explained. For this reason, we often use categories of living and non-living when describing the biotic/abiotic dichotomy in science. Biotic means living, and abiotic means non-living.

However, this language sometimes leads into a misconception of associating living with the state of being alive. Dead stuff is still biotic, or living if we’re using simplified language. Lacking signs of life does not make something abiotic. (Texting teenagers, for example, may not appear alive but still remain classified as biotic.)

This becomes less problematic if we apply the categories to groups, rather than to individuals. Lumber doesn’t resemble a tree, but it is still biotic. Trees are biotic components of the world. Similarly, an infertile individual does not get classified as non-living (abiotic). They are classified along with their whole species, as biotic.

Neither is there is a third, “once-living” category—no “once-biotic.” Sedimentary rocks were formed from the remains of living things millions of years ago. In that sense, the components of rocks were once living, but rocks are classified as non-living.

Biotic: things that reproduce, grow, and die, and the waste from these things
  • plants
  • animals
  • microorganisms
Abiotic: not derived from biotic things

  • air
  • water
  • sunlight
  • rocks
  • etc.

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Photo via US Dept Agriculture, used under CC BY-2.0 license.

10 Feb 2017

Surprisingly Slippery Science

Canada is a land of ice skating.  The longest skating trail in the world (according the Guinness World Records) is a 30 km trail around Lake Windemere in BC. Both our Women's and Men's Hockey teams have the best records in the world. Canadian figure skaters are an international powerhouse. So we really should know how a skate works. But do we?

Many of us have been taught that skates put pressure on the ice, which causes the ice to melt, and the skate then glides on a cushion of water.

It's certainly true that pressure decreases the melting point of ice. The pictures below show this. They're screen captures from an experiment shown in the National Geographic video at

 http://video.nationalgeographic.com/video/i-didnt-know-that/idkt-ice-skating-science
 


Scientists place a wire with weights attached on top of a block of ice. Weights on the thin wire exert a lot of pressure on the ice.


The pressure melts the ice and the wire cuts through the block. The ice re-freezes above the wire as the pressure is released.

But there's a problem. The pressure of a skater is only enough to increase the melting point of ice by less than 1 degree. So how do skates work at -20 degrees?

A second explanation often offered is that the friction of the skate moving across the ice generates enough heat to melt the ice, and that creates the water for the skate to glide on. But that can't be the only explanation.



We've all had the experience of finding out that ice is slippery even when you're standing still. There's no need for friction to melt the ice to make it slippery.

The third answer was known by Michael Faraday as long ago as 1850, but somehow his views were largely ignored. There is always a layer of water on the surface of the ice. That's why two blocks will freeze together if you join them. The water layer occurs because the structure of the ice breaks down at the surface. The thickness of the water layer increases with the temperature of the ice.
Surface of Ice - from Wikimedia Commons


So pressure and friction make a small difference, but essentially skates slide on a layer of water that is always on the surface of the ice.

SkateTechnology

The technology of skates has changed a lot over the ages.

Steven G. Johnson (creative commons licence)
This picture is of medieval bone skates on display at the Museum of London. The accompanying label quoted a 12-century description of skating in London by William FitzStephen (Londoners would "fit to their feet the shinbones of cattle" and propel themselves with an iron-tipped stick).

This is an illustration of modern speed skating "clap skates". In my book Faster, Higher, Smarter you can find out how clap skates work and read the story of how this clever invention took a hundred years to become mainstream in speed skating.