Archive for the 'Mammals' Category

May 23 2016

To Catch A Venomous Mammal…

Published by under Mammals

ZooDom veterinarian Adrell Nunez (center) draws blood from a solenodon for DNA samples, Dominican Republic (photo by Taras Oleksyk and Yashira Afanador)

ZooDom veterinarian Adrell Nunez (center) draws blood from a solenodon for DNA samples, Dominican Republic (photo by Taras Oleksyk and Yashira Afanador)

There are only 16 (maybe 17) venomous mammals on earth and more than half of them are endangered.  One of the rarest is the Hispaniola solenodon (Solenodon paradoxus), native to Haiti and the Dominican Republic.

Solenodons are nocturnal mammals that look like large, big-footed shrews.  They eat beetles, crickets, worms, snails and even birds and reptiles which they paralyze with a bite containing their venomous saliva.  Interestingly, solenodons aren’t immune to each others’ venom so if they fight they succumb when scratched by the teeth of a combatant.  (The Hispaniola solenodon is so poorly studied that we’re not even sure if it fights very often.)

Solenodon paradoxus (photo linked from The Mantis Shrimp blog)

Solenodon paradoxus (photo by Miguel A. Landestoy, linked from The Mantis Shrimp blog)

These mammals evolved in the absence of predators so they are slow, clumsy runners and tend to trip and fall when pursued.  They are now so rare and so endangered that they’re expected to go extinct in the next 10-20 years because of habitat loss and predation by dogs, cats and humans.

With time running out for this animal, scientists wanted to sequence its DNA before it disappeared, and they had to catch it in a manner that was safe for the animal and for them.  But how?

The researchers shown above caught the venomous mammal by allowing it to walk across their bodies at night in the forests of the Dominican Republic.

Yikes!

Read more here in Science Daily.

 

p.s. Did you know there’s a venomous mammal in Pennsylvania?  The northern short-tailed shrew has venomous saliva that paralyzes its small prey.  From Joseph Merritt’s Guide to the Mammals of Pennsylvania, “When humans are bitten, they may experience considerable irritation and swelling that could last up to three days.”  Predators, including house cats, don’t eat this shrew because it smells so bad.

(photo credits:
top photo by Taras Oleksyk and Yashira Afanador of ZooDom veterinarian Adrell Nunez with solenodon.
photo of Hispaniola solenodon by Miguel A. Landestoy, linked from The Mantis Shrimp blog
)

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May 12 2016

May Is The Month for Wayward Bears

Published by under Mammals

Black Bear (photo by Chuck Tague)

Black Bear (photo by Chuck Tague)

On Throw Back Thursday:

May is the month when one-year-old bears are on the road, searching for a first home since mama pushed them out this spring.

If you live in the country you’ve already noticed the bears are active and had to pull in your bird feeders so the bears don’t wreck them. If you live in the city or suburbs you might not realize that bears are possible in your area … until one shows up.

When you see a bear don’t make the mistake of feeding him. He’ll think People=Food and continue to hang around, ransacking the neighborhood.

Last year locals fed marshmallows to a bear in Monroeville!  And he became a problem. And they had to call the Game Commission to trap and transport him.  The Game Commission number in southwestern Pennsylvania is 724-238-9523.

Read more about bears in this 2010 blog post called:  Bears???

 

(photo by Chuck Tague)

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May 09 2016

Nature’s Perfect Partners: PBS NATURE May 11

Barbell fish clean hippo's skin and teeth (photo courtesy PBS Nature © Mark Deeble/Vicky Stone)

Barbell fish clean hippo’s skin and teeth (photo courtesy PBS Nature © Mark Deeble/Vicky Stone)

Oh my!  Is the hippo eating these fish?!?

No. He could eat them if he wanted to but these barbell fish are his helpers.  They eat ticks from his skin and food from his teeth.  It’s a symbiotic relationship.

The hippo and the barbell fish are just one example of the unlikely partnerships animals make with other species.  Watch the premiere of Nature’s Perfect Partners on Wednesday May 11 to learn about many more — lizards with lions, a fish with a blind shrimp, toads with tarantulas.

Here’s a preview:

Don’t miss Nature’s Perfect Partners this Wednesday May 11 at 8pm EDT/ 9pm CDT on PBS.  In Pittsburgh it’s on WQED.

 

(photo courtesy PBS NATURE © Mark Deeble/Vicky Stone)

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Feb 01 2016

Get Ready For Groundhog Day!

Published by under Books & Events,Mammals

Get ready for Groundhog Day!

Tomorrow is the mid-point of winter, halfway between the winter solstice and the vernal equinox.  February 2 is also the day when a very special rodent, Punxsutawney Phil, emerges from his den to predict the weather for the next six weeks.

Phil never makes his prediction in isolation.  His day in the sun (or shade) spawns a huge celebration in Punxsutawney, PA.  Preview the excitement in his eight minute promo video above.

If you don’t like winter, then hope for an overcast sky so that Phil has a day in the shade.  Here’s why.

 

 

(video from Punxsutawney Phil on YouTube)

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Jan 25 2016

Unicorns At Sea

Published by under Beyond Bounds,Mammals

Narwhals

Narwhals “tusking” (photo from Wikimedia Commons)

Did you know there’s a whale with a horn like a unicorn?

The narhwal (Monodon monoceros) is an arctic whale, closely related to the beluga whom it resembles.

Close relatives: Beluga whale and narwhal (illustration from Wikimedia Commons)

Close relatives: Beluga whale and narwhal (illustration from Wikimedia Commons)

Like the beluga, it has teeth though it doesn’t use them for chewing.  All but two of the teeth are vestigial but one of those, the left canine, grows though the male’s upper lip spiraling counter-clockwise, straight out, in a single tusk as much as nine feet long.

The tusk is not a sword.  Instead, like our teeth it’s made up of layers but it’s hollow inside and much more sensitive.  The outer layer is permeable, allowing seawater to pass through the dentin into the hollow core filled with millions of nerves. Scientists know the tusks can sense salinity but they probably can sense a lot more. When narwhals surface to breathe and rub tusk to tusk they’re not fighting, they’re communicating.

Narwhals are so specialized it may lead to their extinction.  They live only in the Arctic Ocean where they depend on its icy habitat for food and shelter.  They roam in pods of 5-10 individuals and may migrate in groups of 1,000 but they seem more loyal to their favorite sites than to following their food.  As climate change heats the water and melts the arctic ice, narwhals will have less food and fewer places to live. Like the polar bear, narwhals are threatened by climate change.

If or when this whale goes extinct it may pass into mythology, like the unicorn.

Unicorn in the Book of the properties of Bartholomew the Englishman, early fifteenth century (illustration from Wikimedia Commons)

Unicorn in the Book of the properties of Bartholomew the Englishman, early fifteenth century (illustration from Wikimedia Commons)

 

(photos from Wikimedia Commons. Click on the images to see the originals)

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Jan 22 2016

Why The Apple Tree Came Down

Published by under Mammals

One autumn evening in Sweden, a man came home from his nighttime job and heard a strange bellowing in the dark coming from his neighbor’s apple tree.

A drunken moose was calling for help!

To rescue the moose they had to chop down the tree.

And that’s why the apple tree came down.

 

(video from YouTube)

p.s. The moose had been eating fermented apples.

 

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Jan 19 2016

Caracara, Capybara

Published by under Beyond Bounds,Mammals

Yellow-headed caracara on capybara (photo from Wikimedia Commons)

Yellow-headed caracara on capybara (photo from Wikimedia Commons)

Hawk on pig?  Well, almost…

Caracara on capybara.

The bird is a yellow-headed caracara (Milvago chimachima), a member of the falcon family native to South America(*) and similar in size to a Cooper’s hawk.

The mammal is a capybara (Hydrochoeris hydrochaeris), the world’s largest rodent. Its scientific name is Greek for “water pig.”  Its English name means “eats slender leaves” in the extinct Tupi language of Brazil.

Semi-aquatic, vegetarian, and closely related to the guinea pig, capybaras swim a lot.  They eat grass and aquatic plants which fortunately wear down their continuously growing teeth.  They also eat their own feces to get more nutrition out of their partially digested food.

Capybaras are big.  They stand as tall as a German shepherd but of course they’re not the same shape and they weigh a lot more.  For a sense of scale, here’s a group of capybaras grazing in a park in Brazil.

Capybaras grazing at Parque Barigüi, Curitiba, Brazil (photo from Wikimedia Commons)

Capybaras grazing at Parque Barigüi, Curitiba, Brazil (photo from Wikimedia Commons)

These groups are typical.  Capybaras are very social and live with 10-20 and up to 100 other individuals.  The round bump on their snouts is a scent gland called a morillo which they rub on everything to say “I’m here.”  They also use anal scent glands and urine for the same purpose.  Obviously capybaras do not make good pets.

As for the bird, why is the caracara on the capybara?

More on that tomorrow.

 

(photos from Wikimedia Commons. Click on the images to see the originals.)

(*) Both the bird and the mammal have increased their range into southern Central America.

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Jan 08 2016

Natural Born Hustlers: PBS NATURE

Are humans the only species that fools others to survive, find food, and mate?  Not at all!

This month PBS NATURE premieres a new three-part series, Natural Born Hustlers, airing on PBS on Wednesdays, January 13, 20 and 27 at 8:00pm (ET) (check local listings).

Episode One, Staying Alive, focuses on survival techniques:  camouflage, dominance tricks, audio mimics and playing dead.  Early on I was amazed to learn how zebras’ stripes create an optical illusion.  You have to see them in motion to believe it!

Other fascinating finds are the amazing skin-morphing camouflage of cuttlefish, the lizard that walks like a stinky beetle, and the white-faced capuchin monkeys who calculate whether they’re needed in battle.  “More capuchins are killed by their own kind than by predators,” says the episode.  What an unfortunate trait to have in common with humans.

The video excerpt above gives you a good idea of animals’ ingenuity.  California ground squirrels use their enemy’s scent as protective camouflage.  Their arch enemy is the rattlesnake, so if you hate to look at snakes this video will make you flinch.

And fair warning to those afraid of snakes:  Staying Alive has quite a few snakes in it including a match-up in North Carolina of a harmless species that mimics the coral snake.  The bonus is that you can identify birds by song on the audio track.

 

(Natural Born Hustlers trailer from PBS NATURE)

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Dec 28 2015

In The Beavers’ County

Chopped! Raccoon Creek State Park, Dec 2015 (photo by Kate St. John)

Chopped! at the Wetlands Trail, Raccoon Creek State Park, Dec 2015 (photo by Kate St. John)

This month I hiked the Wetlands Trail at Raccoon Creek State Park in Beaver County where I found many small trees chopped down next to Traverse Creek lake.  Across the water, cut treetops and shrubs lay in a messy half-submerged brush pile against the opposite shore.

The stumps don’t show the straight-edge cut of human activity.  If you look closely you see tooth marks.  Big incisors were at work.

Beavers!

The remains of a stand of alders, Raccoon Creek State Park, Dec 2015 (photo by Kate St. John)

The remains of alders, Raccoon Creek State Park, Dec 2015 (photo by Kate St. John)

Beavers (Castor canadensis) are obviously here now, but that wasn’t always the case.

When Beaver County was named for the Beaver River in 1800, their namesake was already hard to find.  The North American beaver population was 100 to 400 million before Europeans arrived to trap them but 300 years of over-hunting took its toll.  According to the PA Game Commission, “the last few beavers known to naturally exist in Pennsylvania were killed in Elk, Cameron, and Centre counties between 1850 and 1865.”

Game laws and reintroduction programs have brought beavers back to 10% of their former population. Today there are 10 to 15 million beavers in North America.

In Pennsylvania one indication of the beavers’ success is the number of complaints they generate, mostly about flooding including plugged culverts and flooded roads.  A lot of complaints often means there are a lot of beavers.

Where were the most complaints in 2008 in southwestern Pennsylvania?

In Beaver County.

 

(photos by Kate St. John)

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Dec 14 2015

Another Alien Invader

Published by under Mammals

Little brown bat with white nose syndrome (photo by USFW via Wikimedia Commons)

Little brown bat with white nose syndrome (photo by USFW via Wikimedia Commons)

Here’s news that surprised me about white nose syndrome, the disease that’s wiping out bat populations in eastern North America.

White nose syndrome (WNS) is caused by a cold-loving fungus, Pseudogymnoascus destructans, that thrives in temperatures 40-200 C (390– 680 F), which happens to be the winter temperature in caves where bats hibernate.

The fungus attaches to the bat’s exposed skin — nose, wings, ears — where it looks like white powder.  It doesn’t kill bats directly. Instead it eats away at their skin, causing irritation, dehydration, and higher metabolism that burns up their fat stores.(*)  The bats rouse themselves and fly around on mid-winter days looking for food.  There aren’t any flying insects to eat so they starve and die. Millions of them.

Since white nose syndrome first appeared nine years ago near Albany, NY the toll has been devastating.  The fungus has spread rapidly from state to state and into Canada, ultimately reducing some bat populations by 95%.  It was confirmed in western Pennsylvania in the winter of 2010-2011 and this year in Oklahoma.  There’s a real possibility that the little brown bat will go extinct in the next 15 years.

Bat researchers are now in a race against time to stop the fungus.  Meanwhile they found out where it came from: Europe.

How did it get here?

In The Sixth Extinction: An Unnatural History Elizabeth Kolbert describes its probable path as told by NY DEC’s Al Hicks.  The first record — in 2006 — was photographed in “a cave connected to Howes Cave, a popular tourist destination which offers, among other attractions, flashlight tours and underground boat trips.  “It’s kind of interesting that the first record we have of this is photographs from a commercial cave in New York that gets about two hundred thousand visits a year,” Hicks told me.”

And so it’s likely that someone with spores on their clothing or gear got on a plane in Europe and visited a cave near Albany.

It’s amazingly easy to introduce an alien invader.

 

(photo by U.S. Fish and Wildlife via Wikimedia Commons. Click on the image to see the original)

p.s. I highly recommend The Sixth Extinction: An Unnatural History by Elizabeth Kolbert.  It’s a great book, full of detective stories like this one.

(*) Click here for an article that answers the question: How Does White Nose Syndrome Kill Bats? Thanks to Deb Grove for the link.

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