Category Archives: Mammals

Dolphins Tell Fishermen When To Throw Nets

Bottlenose dolphins on the ocean (photo from Wikimedia Commons)

For more than 173 years humans and dolphins have worked together to catch fish on the coast of Laguna, Brazil. Dolphins initiated the cooperation some time before 1847 and taught humans what to do.

The dolphins hunt by herding shoals of mullet in the estuary. The fish would escape into shallow water except that the humans are helping.

Fishermen stand in the water with cast-nets and wait for a dolphin to signal them. When the signal comes, the fishermen throw their nets and catch many fish. The rest of the fish flee to deeper water where the dolphins are waiting to eat them.

Humans and dolphins both catch more fish than they would working alone.

Watch how it’s done in this Animal Planet video.

(photo from Wikimedia Commons; click on the caption to see the original)

Fox Versus Weasel: Who Will Win?

Fox at Algonquin (photo from Wikimedia Commons)

Red foxes and short-tailed weasels (called “stoats” in the UK) are both carnivorous predators.

Short-tailed weasel, also called a Stoat or Ermine (photo from Wikimedia Commons)

In the U.K. red foxes (Vulpes vulpes) are twice as tall as stoats (Mustela erminea) and outweigh them by 13 pounds (23 times heavier!) but stoats are fierce and almost fearless, killing prey four times larger than themselves. In the UK, male stoats easily kill European rabbits (photo here).

What happens when a fox hunts a stoat? This video tweeted by @kremington11 provides one answer.

I’m sure a fox-vs-stoat battle doesn’t always end this way but you can bet that this particular fox has reconsidered his desire to eat stoats.

@DeanLittleHigh‘s reply is exactly on target.

If stoats were the size of labradors weโ€™d have run out of cows by now.

(photos from Wikimedia Commons; video embedded from Twitter)

p.s. Short-tailed weasels / stoats turn white in winter. Their winter fur is called ermine.

Ravagers of Jewelweed

Jewelweed browsed by deer, Schenley Park, Aug 2020 (photo by Kate St. John)

Seven years ago yellow (Impatiens pallida) and orange (Impatiens capensis) jewelweed were so plentiful in Schenley Park that their flowers attracted bumblebees, hummingbirds and my own curiosity. I often blogged about them as in this August 2013 article: Experiments with Jewelweed.

But all that has changed. In the last seven years the deer population in Schenley Park has exploded. Without predators deer can double their population in just two to three years. Two deer became 16 … and Schenley started with more than 2.

Meanwhile, edible plants have not increased exponentially and they can’t keep up with the heavy browsing. Jewelweed is a deer favorite so it’s routinely “mowed” to ankle height.

A large patch of jewelweed ‘mowed’ by deer, Schenley Park, Aug 2020 (photo by Kate St. John)

A few individuals are able to sprout new leaves while the deer consume other areas but these recovering plants are few and far between.

This summer it’s hard to find a complete plant.

Jewelweed sprouts after deer browsing, Aug 2020 (photo by Kate St. John)

The situation bothers me but has posed real problems for Andrea Fetters of the University of Pittsburgh who is studying pollen-associated viruses in Impatiens capensis and Impatiens pallida. She has so few study objects in Schenley Park that she’s had to add study sites north of Pittsburgh where jewelweed thrives because deer aren’t so plentiful.

Unfortunately the number of deer in Schenley Park is not going down any time soon. Predators, other than cars, would solve the problem. My friend Andrea Boykowycz suggests cougars, the “Pitt panther” mascot. It would be fitting to have two in Panther Hollow. Well, we already do but they’re frozen in place.

One of two panther statues at the Panther Hollow Bridge (photo from Wikimedia Commons)

Meanwhile, the ravagers of jewelweed keep eating.

(photos by Kate St. John)

Bumblebee and Deer

Last week in Schenley Park I stopped by the Westinghouse Fountain to see swamp milkweed and a photogenic bumblebee.

My cellphone camera was able to capture it in flight!

As I left the fountain a doe crossed W Circuit Road and walked between parked cars to the woods beyond. A fawn soon followed but jumped back in fear before the cars and stopped in the road. Fortunately there was no traffic. It was joined by a second fawn.

The two approached me (I missed that shot) then turned away …

… and were joined by a second doe.

Eventually they all walked between parked cars and caught up with the first doe.

Schenley Park’s numerous deer aren’t afraid of people but they learn to fear cars at a very young age.

p.s. My cellphone can take nice closeups of bumblebees but fails on deer at a distance.

(photos by Kate St. John)


Western grebes with piggyback chicks (photo from Wikimedia Commons)

Some animals such as western grebes (above) and giant anteaters (below) carry their young piggyback.

Pigs don’t do this so why is it called piggyback?

The term began as two words that morphed into “piggy + back.” Here’s the origin from World Wide Words.

It started out in the sixteenth century as “pick pack,” carrying something on the back or shoulders. Pick is a medieval version of pitch, so it meant a load that was pitched on to a person’s back for carrying. โ€ฆ Piggy-back came along later in the century, with piggyback a modern loss of the hyphen

Origin of piggyback from World Wide Words

At first it was “pick pack.”

Women carrying wood “piggyback” (photo from Wikimedia Commons)

Now it’s piggyback.

Happy family — piggyback (photo from Wikimedia Commons)

Happy family.

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

New Mammal in The Heart of Frick Park

Aspen felled by a beaver, Nine Mile Run, 20 July 2020 (photo by Kate St. John)

25 July 2020

Last week I found an aspen lying in the creek that used to be its home. The cone shape of the stump means a beaver felled this tree.

Aspen felled by a beaver, Nine Mile Run, Frick Park, 20 July 2020 (photo by Kate St. John)

Beaver evidence is common at Moraine State Park, Raccoon Creek and even at Pittsburgh’s North Shore and on Washington’s Landing island. What makes this scene unusual is that it’s in the heart of Frick Park.

The felled aspen is next to the new upper boardwalk on Frick Park’s Nine Mile Run Trail. (See the edge of boardwalk in the photo below.)

Beaver evidence is next to the upper boardwalk on the Nine Mile Run Trail, Frick Park, 20 July 2020 (photo by Kate St. John)

I’ve seen beaver evidence along the Monongahela River near Duck Hollow so I’m not surprised that a beaver swam or walked up Nine Mile Run. When he got to the boardwalk he found the perfect habitat: a shallow waterfall (man-made) and lots of trees to eat.

I haven’t seen the Frick Park beaver but I’ve seen a photo.

It’ll be interesting to see what happens next. ๐Ÿ˜‰

(photos by Kate St. John)

Male Mice Sing To Attract The Ladies

House mouse (photo from Wikimedia Commons)

22 July 2020

This morning I searched my blog for information on birdsong and was stopped in my tracks by a fascinating article: Male house mice (Mus musculus) sing to woo the ladies.

We don’t realize this because we can’t hear them. Mouse voices are way above our range of hearing but within the hearing range of cats (of course).

Mice sing at a shrill 50 kilohertz (kHz)โ€”and our hearing tops out at just over 20 kHz. Mouse songs might be audible to cats, though, which can hear up to about 65 kHz.

Audubon News: Animal Kingdom Idol: Birdsong vs. Mouse Song

Learn more and watch a male mouse sing in this 2015 article: Mr. Mouse Went A-Courting. (Duke University digitally lowered the audio frequency so we can hear the song.)

(photo from Wikimedia Commons; click on the caption to see the original)

Yes, Deer Eat Birds

Summertime buck at Allegheny Cemetery, Pittsburgh (photo from Wikimedia Commons)

Songbirds have good reason to fear white-tailed deer. Contrary to popular belief, deer are not vegetarians. Though they forage on plants they will eat eggs and baby birds when they encounter them. Some people have seen it. Trails cams show the rest of us.

Be alert when you hear a songbird freak out in the presence of deer. There’s a reason. Learn more and see a video in this vintage article: Deer Are Not Vegetarians.

Deer browsing the ground (photo from Wikimedia Commons)

(photos from Wikimedia Commons; click on the caption to see the original)

Squirrel Proof Feeder?

Squirrel on the bird feeder (photo from Wikimedia Commons)

Are you frustrated with squirrels at your bird feeder? Are they getting into squirrel-proof locations?

Not quite squirrel-proof (photo by Marcy Cunkelman)

You’re not alone.

This spring Mark Rober was frustrated that squirrels were getting into his new bird feeder so he bought a better one, and then an even better one, and they still got in. So he decided to build a squirrel obstacle course to see just how agile these critters are. In the process he actually got to know each squirrel. And he made a video.

Watch as the squirrels are foiled and challenged and then …. well, you’ll just have to watch. The video lasts 20 minutes. If you don’t have that much time watch the first 3 minutes. I bet you’ll be hooked. ๐Ÿ˜‰

(photos from Wikimedia Commons; click on the captions to see the originals. Embedded video by Mark Rober)

Reindeer Are Off The Clock

Reindeer at Svalbard (photo from Wikimedia Commons)

I don’t know about you, but I often check my watch or cellphone to find out what time it is. Do you ever wish that the time of day didn’t matter? It doesn’t matter to reindeer.

Reindeer live in daylight all summer and darkness all winter so they threw out their daily internal clocks a long time ago. Find out how they did it in this vintage article: They’re Off The Clock.