Category Archives: Mammals

Not Dead, Just Resting

Virginia opossums (Didelphis virginiana) walk with a bumbling gait and have poor eyesight and hearing so when they finally notice danger it’s very close at hand.  They’ve evolved a pretty good solution to protect themselves.  Possums fall over and play dead.

Playing dead is triggered by extreme fear and it’s involuntary — like fainting.  The possum enters a near coma, lying on its side with its mouth and eyes open and tongue hanging out.  Meanwhile it exudes a putrid green fluid from its anus that’s unappetizing to predators.

The possum in this video was probably shocked when the big black dog showed up. Boom! He fell over.

But how to remove him?

Wait and he’ll wake up and walk away. Put the dog indoors and he’ll do it sooner.

He’s not dead. He’s just resting.

Oh, The Opossum!

Virginia Opossum (photo by Chuck Tague)
Virginia Opossum (photo by Chuck Tague)

My blog about rabies prompted a comment from Joyce Peronne about the Virginia opossum (Didelphis virginiana).

Did you know that possums are resistant to rabies, though not immune?

On Throw Back Thursday, click the links to read more amazing facts about this underappreciated mammal.

Oh, the opossum!

 

(photo by Chuck Tague)

Lawn Chemicals Linked To Dog Cancer

Dogs ready to play (photo from Wikimedia Commons)
Dogs ready to play (photo from Wikimedia Commons)

This news is so old that I’m amazed I didn’t learn it until last month.

Weed killers save time but researchers have known for decades that their use is linked to cancer in dogs.

Spraying a dandelion with weed killer (photo from Wikimedia Commons)
Spraying a dandelion with weed killer (photo from Wikimedia Commons)

2,4-D is a widely used weed killer that’s been around since the 1940s.  It kills broadleaf weeds by causing uncontrolled growth in them, sort of like cancer in weeds.

Why study dog cancer?

Of course we love our dogs and want to know about their illnesses, but there’s an additional reason to study dog cancer.  Canine malignant lymphoma (CML) is so similar to non-Hodgkins lymphoma (NHL) in humans that CML is used as a model for NHL.

Linking lawn chemicals to dog cancer:

  • A 2012 study showed a 70% higher risk of dog cancer (CML) in households that used professionally applied lawn chemicals. Fortunately, they found that flea and tick controls are unrelated to the risk of CML.  Click here for the study.
  • And a 2013 study found an increased risk of bladder cancer in dogs exposed to professionally applied lawn chemicals. Click here for the study.

There’s a growing body of evidence that lawn chemicals — especially 2,4-D — are bad for humans.  I didn’t realize that for 27 years we’ve known they’re bad for dogs.

 

(photos from Wikimedia Commons; click on the images to see the originals)

p.s. In July 2017 California added glyphosate (the active ingredient in Roundup) to their list of potentially cancerous chemicals.

What About Rabies?

Raccoon and skunk (photos from Wikimedia Commons)
Raccoon and skunk (photos from Wikimedia Commons)

When I wrote about skunks last Friday, I said that “skunks carry rabies” but revised the text when Nathalie Picard pointed out that “carry” is misleading.  Today I’ll explore the subject of rabies, who is at risk, and why the word carry is used for this disease.

Rabies is a virus that causes inflammation of the brain and death in mammals.  Its pathway to humans is by a bite or scratch from an infected animal.  When the virus first enters a human there are typically no symptoms for one to three months, though that period can range from 4 days to several years. During the asymptomatic period the victim feels fine.

When symptoms finally appear rabies has reached the fatal stage and the victim will die in 2-10 days. The only cure is a preventive vaccine (PEP) which must be administered within a few days of the original bite, long before symptoms appear.  (Read more here.)

Dogs are the main hosts and transmitters of rabies. Worldwide more than 17,000 humans die of rabies every year, 99% of them from dog bites.  95% of the deaths occur in Asia and Africa where dog rabies is poorly controlled and the post-exposure vaccine is unavailable.  More than a third of the deaths occur in India. (quoted from World Health Organization)

Thirsty dog in India (photo from Wikimedia Commons)
Thirsty dog in India (photo from Wikimedia Commons)

In the U.S. 92% of rabies comes from wildlife — bats, raccoons, skunks and foxes — called “rabies vector species” because they are at high risk for catching the disease.  Since post-exposure prophylaxis (PEP) is readily available here, only 2 or 3 people die of rabies per year.

Bats are the main cause of rabies death in the U.S. because people either do not realize they were bitten by a bat while sleeping/drunk/disabled or they do not seek treatment.  Those who handle wildlife are vaccinated against rabies in advance.

Biologist holds a little brown bat (photo by USFWS/Ann Froschauer via Wikimedia Commons)
Biologist holds a little brown bat (photo by USFWS/Ann Froschauer via Wikimedia Commons)

Here’s a graph of the CDC’s rabies statistics by species in the U.S. in 2015.  All mammals can catch rabies. The low percentage species are lumped in the “All Other” category.

Rabies Reports by Species in U.S., 2015 (graph created from data at CDC.gov)
Rabies Reports by Species in U.S., 2015 (graph created from data at CDC.gov)

Aside from bats, raccoons are the main rabies vector in the eastern U.S. while skunks are the main vector elsewhere.  Foxes are also a vector in Arizona, New Mexico and Alaska.  (See CDC map here)

And finally … Why is the word “carry” used about rabies?
Wikipedia defines a disease carrier as a person or organism who’s infected by a disease but displays no symptoms.  Since rabies has no symptoms at first, those with early stage rabies can be described as carrying it.   High risk species are “vectors” not carriers. They don’t carry rabies until they catch it.

The bottom line is this:  Avoid approaching wildlife, especially rabies vector species. Most of them are fine but you never know.  If you are bitten or scratched, don’t wait to visit the doctor.

 

(photos from Wikimedia Commons; click on the images to see the original.  In the composite photo at top: raccoon by D. Gordon E. Robertson and skunk by K. Theule/ USFWS)

A Way To Get Rid of Yellow Jackets

Skunks smell bad, they can make you smell bad, they’re at high risk for rabies(*), and they eat bees and eggs causing problems for beekeepers and chicken farmers.

However, they have one benefit:  They eat yellow jacket wasps.

This spring Marcy Cunkelman remarked that a skunk keeps her yard free of yellow jackets and grubs.  The skunk leaves holes but that’s better than stepping on a yellow jacket nest!

The video above shows a skunk digging for grubs.

The video below shows a skunk eating a yellow jacket nest.   (Warning: It has music that sticks in your head all day!  It also has subtitles so you don’t need the sound on. But you might be curious. What song is it?)

 

(videos embedded from YouTube. click on the videos to see the originals)

(*Rabies)  Skunks are at high risk for catching rabies and are therefore called a “rabies vector species.”

In all mammals — humans as well as skunks — rabies does not make the animal feel and look sick until the rabies infection has reached the fatal stage.  If you are bitten by a wild animal you cannot tell if it has rabies. The hidden illness is sometimes described as “carrying rabies.”

You’ll Want Him On The Boat

Newfoundland ready for a water rescue (photo from Wikimedia Commons)
Newfoundland ready for a water rescue (photo from Wikimedia Commons)

Gentle, loyal, strong and intelligent Newfoundland dogs love to swim.

For centuries Newfoundlands have been bred on the island to be fishermen’s working dogs — performing water rescues, hauling fishing nets, and pulling carts.  Weighing up to 150 pounds, they are big.

Their double thick fur, muscular build, webbed feet and great swimming ability make them especially valuable for water rescue. In fact they’re so good at it that they’re entered into sea rescue competitions. The dog in the photo below is doing a “handholding” exercise in France, swimming the man to safety by holding his hand.

Sea rescue "handholding" exercise performed by a Newfoundland dog at the port of Ploumanach, France (photo from Wikimedia Commons)
Sea rescue “handholding” exercise performed by a Newfoundland dog at the port of Ploumanach, France (photo from Wikimedia Commons)

Even untrained Newfoundlands will leap to aid people in distress in the water.  Wikipedia recounts this example:

In 1995, a 10-month-old Newfoundland named Boo saved a hearing-impaired man from drowning in the Yuba River in Northern California. The man fell into the river while dredging for gold. Boo noticed the struggling man as he and his owner were walking along the river. The Newfoundland instinctively dove into the river, took the drowning man by the arm, and brought him to safety. According to Janice Anderson, the Newfoundland’s breeder, Boo had received no formal training in water rescue.

Newfoundlands have a Pittsburgh connection: In the summer of 1803 Meriwether Lewis was in Pittsburgh waiting for his boats to be completed so he could start his journey down the Ohio to meet up with William Clark (in Indiana) and begin the Lewis and Clark expedition. While he was here Lewis purchased a Newfoundland dog named Seaman for $20. Seaman was the only animal to complete the trip to the Pacific coast and back. (Read more about Seaman here.)

Today Newfoundlands are also kept inland as pets but on the island you can sometimes find them at work on the water.  And no wonder.  If you lived in a place where the cold ocean can kill a man in less than hour, you’d want this dog on the boat.

 

p.s.  Newfoundlands and Labrador retrievers are related. Both were bred in the province for which they are named. They’re honored by this statue on Signal Hill in St. John’s, NL.

Statue honoring Newfoundland and Labrador retriever dogs, Signal Hill, St. John's, NL (photo by Kate St. John)
Statue honoring Newfoundland and Labrador retriever dogs, Signal Hill, St. John’s, NL (photo by Kate St. John)

(photo of dog statue in St. John’s by Kate St. John.  All other photos from Wikimedia Commons; click on the images to see the originals)

Trip is over. I’m back home in Pittsburgh.

 

Let’s Go, Kids

  • Uh oh! We've been seen.

Last week in Schenley Park I heard unusual mewing sounds above me.  Three raccoon kits were whining as their mother assessed whether I was dangerous. She saw me before I saw her family.

Eventually Mama decided her kits should move up the tree for safety’s sake.  “Let’s go, kids!”

After they were safely (almost) hidden she looked down to see if I was gone.  That tiny tail in the last photo is one of her kits.

(photos by Kate St. John)

 

A Fawn In The Backyard

Fawn inside the anti-deer fence (photo by Jennie Barker)
Fawn inside the anti-deer fence (photo by Jennie Barker)

May is the month when fawns are born but it’s rare that you ever see them.

Fawns hide from predators by not moving as they sleep in dappled sunlight that matches their fur.  Their mothers move away from them so the adults don’t attract attention to their fawns’ location.  At night the family reunites.

Sometimes the family picks a “hiding” place that’s visible.  In 2011 Jennie Barker found a fawn in her suburban Pittsburgh backyard.

On Throw Back Thursday, read about her discovery at: Two Mornings of a Fawn

 

(photo by Jennie Barker)

Let’s Talk About Coyotes

Eastern coyote (photo by ForestWander via Wikimedia Commons)
Eastern coyote (photo by ForestWander via Wikimedia Commons)

Taking a break from peregrines today …   Let’s talk about coyotes.

Last fall a coyote showed up in my city neighborhood and was seen at dusk in several locations before he moved on a month later.

Coyote in the City of Pittsburgh, October 2017 (photo by Luanne Lavelle)
Coyote in the City of Pittsburgh, October 2017 (photo by Luanne Lavelle)

We were all surprised that a wild animal chose to be among us and it made me curious. Why would a coyote come to town?  How did coyotes get here?

The answers became a radio piece on The Allegheny Front last week.  Listen to the story here:  When Coyotes Come To Town

Even when coyotes are present they are rarely seen but are sometimes heard.  In urban settings they respond to sirens (click here for a sirens video from Tucson, Arizona(*)

Friends in Pittsburgh tell me they’ve heard coyotes in Sewickley Heights Park, Scott Township, and Hazelwood Greenway.

Have you heard coyotes near you?  Leave a comment and let me know.

 

(photo credits: Coyote closeup by ForestWander via Wikimedia Commons. Click on the image to see the original. Coyote in Greenfield in October 2017 by Luanne Lavelle)

(*) p.s. Every time I listen to the Tucson video it makes me laugh.  The siren wails, the coyotes wail back.  On and on.

Only The Size of a Squirrel

Geoffroy's tamarin at a bird feeder at Cerro Azul, Panama (photo by Donna Foyle)
Geoffroy’s tamarin at a bird feeder in Cerro Azul, Panama (photo by Donna Foyle)

When I see photographs of monkeys I think they’re at least the size of chimpanzees but this monkey, native to Panama and northern Colombia, is only the size of a squirrel.

Geoffroy’s tamarins (Saguinus geoffroyi) are small colorful members of the marmoset family with bodies only 9 inches long but tails up to 15 inches.  They live together in family groups of three to five individuals, traveling through the trees to find their favorite foods of insects and fruit.  The brave ones visit bird feeders.

Bird feeders in the tropics are different from ours at home.  Pennsylvania birds are attracted to seeds, suet and mealworms but tropical birds eat fruit so Panamanians put bananas, mangoes and papaya in their feeders.  This inevitably attracts the monkeys.

At Cerro Azul we met a homeowner who feeds Geoffroy’s tamarins in her backyard every day.  If she isn’t quick to fill the feeders they whine at her from the trees, but they are shy and won’t come down unless she is alone.

We all stood far away and Donna Foyle took pictures while the homeowner stabbed fruit chunks with the tip of a knife to hand it to the monkeys.  Later she handed fruit to them directly.

Homeowner feeding backyard monkeys at Cerro Azul, Panama (photo by Donna Foyle)
Homeowner feeding Geoffroy’s tamarin at Cerro Azul, Panama (photo by Donna Foyle)
Geoffroy's tamarin grabs fruit off the knife at Cerro Azul, Panama (photo by Donna Foyle)
Geoffroy’s tamarin grabs fruit off the knife at Cerro Azul, Panama (photo by Donna Foyle)
Homeowner feeding backyard monkeys at Cerro Azul, Panama (photo by Donna Foyle)
Homeowner feeding backyard monkey at Cerro Azul, Panama (photo by Donna Foyle)
Geoffroy's tamarin eating fruit offered by a homeowner at Cerro Azul, Panama (photo by Donna Foyle)
Geoffroy’s tamarin eating fruit offered by a homeowner at Cerro Azul, Panama (photo by Donna Foyle)

Squirrels are scarce in the Panamanian jungle.  We saw only one in Panama and it was at the airport hotel.  So Geoffroy’s tamarins fill the niche of squirrels at the bird feeders.

These “squirrels” have thumbs!

 

Read more here about Geoffroy’s tamarin and see a photo of one with a baby on its back.

(photos taken at Cerro Azul on 23 March 2018 by Donna Foyle)