Category Archives: Mammals

A Bear Was There

Black bear track with human hand and dog pawprint for scale, 22 July 2021, Moraine State Park (photo by Kate St. John)

25 July 2021

When four of us walked the Muddy Creek Trail at Moraine State Park last week we found something we hadn’t expected. In the mud at our feet was a very large footprint. A bear was there.

None of us knew much about animal tracks but the footprint was unmistakably a large black bear (Ursus americanus), easy to identify because it’s the only bear species in Pennsylvania. Debbie hovered her hand nearby for scale.

Why is this bear track so narrow front-to-back? Black bears don’t roll their feet heel-to-toe like we do so their heels don’t always register. This illustration from the National Park Service shows front and hind tracks. I have shaded the heels that leave shallow or no prints. Bears step forward on their tiptoes. (*)

Track of a black bear, shaded to show registration (image originally from Yellowstone

Immediately we wondered how recently the bear had walked by. Was it hiding in a nearby thicket? The track tells a story, some of which I am too uninformed to decipher.

At first glance the bear print seems to show just palm pad, toes and claws, but a smaller print came later, superimposed on the bear’s shallow-registered heel. The smaller mammal walked by after the bear was gone, perhaps long gone.

Who was that smaller mammal? People walk their dogs on this trail. Was it a dog print? I know very little but I’ll attempt to identify it. (I used for these details.)

The print is round and doesn’t show any claws (canines usually show claws). The fourth toe is lower than the others, the second toe is highest. My guess is it’s a feline and too large for a house cat. Was it a bobcat? I should have taken more photos.

I did take more bear track photos. Here’s a hind foot. Notice the pointy heel.

Black bear track, hind foot, 22 July 2021, Moraine State Park (photo by Kate St. John)

And perhaps a front foot.

Black bear track, 22 July 2021, Moraine State Park Muddy Creek Trail (photo by Kate St. John)

In any case, both animals were gone before we arrived. Pennsylvania black bears avoid people unless habituated to our feed or garbage.

Why was the bear there? Bears use our trails and roads for the same reason we do. It’s easier than wading through the underbrush.

(*) Did you know that cats and dogs always walk on their tiptoes? A subject for another day.

(photos by Kate St. John)

Backyard Cats

Bobcat in a Tucson backyard (photo by Donna Memon)

9 July 2021

Backyard cats in Arizona are a lot more interesting that the ones we have in Pittsburgh.

Instead of small domestic pets or feral cats, both Felis catus, Arizonans have bobcats (Lynx rufus) that come to drink from the water bowls …

Bobcat in a Tucson backyard (photo by Donna Memon)

… then lay down in the shade …

Bobcat yawns in a Tucson backyard (photo by Donna Memon)

… and have a nice long sleep.

Be careful when you open the door!

(photos by Donna Memon; embedded tweet from @KateSmithAZ)

Stay Away From My Baby

Raven strafes a coyote that got too close to her youngster (screenshot from tweeted video by @CrytzerFry)

8 June 2021

Ravens and coyotes can work together but not when a fledgling raven is involved. A motion detection camera captured this mother raven’s reaction when a coyote came too close to her fledgling.

Keep your distance! Stay away from my baby!

p.s. Sometimes ravens and coyotes work together. See these anecdotes from the Adirondacks ( and San Francisco (

(screenshot from embedded Twitter video by Melissa Crytzer Fry @CrytzerFry)

Back Up So I Can Take Your Picture

Short-tailed weasel (photo from Wikimedia Commons)

6 April 2021

Clare Kines @NunavutBirder tweeted this encounter with a short-tailed weasel.

Also known as stoats or ermines, short-tailed weasels (Mustela erminea) have a circumpolar distribution. This one was filmed in Nunavut, the most northern of Canada’s Arctic territories.

See more at Clare Kines’ award-winning photography website.

(tweet by Clare Kines. photo from Wikimedia Commons)

Birds Decline, Small Mammals Thrive in a Hotter World

Cactus mouse (photo by J.N. Stuart, Creative Commons license via iNaturalist)

8 March 2021

What is the future of life on Earth as the climate warms? Which species will thrive and which decline? A study published last month in Science indicates that “in a warming world, it’s better to be a small mammal than a bird.”

In the early 1900’s Joseph Grinnell made extremely detailed records of flora and fauna in California’s Mojave Desert for the Museum of Vertebrate Zoology. A century later the average temperature in the Mojave is now 2oC (3.6oF) higher. Using Grinnell’s records a team led by Eric Riddell resurveyed Grinnell’s locations to find out how birds and mammals fare in hotter, drier conditions.

If you like birds, you won’t like the news.

[In the Mojave Desert] Over the past century, occupancy of small mammals remained stable while birds severely declined.

On average, every spot surveyed had lost more than 40% of its desert bird species, such as American kestrels or mountain quail. At most sites, even the remaining species were scarcer.

Science Magazine: In a warming world it’s better to be a small mammal than a bird.
American kestrel, 2013 (photo by Cris Hamilton)

Small mammals get around the heat problem by staying underground during the day. Birds don’t have this choice and they have an additional disadvantage — their bodies use more energy to stay cool.

It looks like there will be fewer birds in a hotter world. Read more in Science Magazine: In a warming world it’s better to be a small mammal than a bird.

p.s. There is a bird who stays underground during the day and eats small mammals in the Mojave Desert: the burrowing owl.

(cactus mouse photo by J. N. Stuart via iNaturalist (CC BY-NC-ND), American kestrel photo by Cris Hamilton)

Was The Close-up Worth It?

Striped skunk, Cokeville Meadows NWR, Wyoming, Sept 2015 (photo by K. Theule/ USFWS)

This is not my story but it’s a good one.

In September 2015 K. Theule of the US Fish and Wildlife Service was in the office at Cokeville Meadows NWR, Wyoming when she saw a skunk outside the window. She picked up her camera and …

Sometimes as a photographer, I don’t make the wisest decisions. Usually it’s a light or angle or exposure mishap. However, today my risk assessment wasn’t fully completed before I poked my head out the office door. After pressing the shutter a few times I was left wondering if the smell was going to last. But who can resist a skunk only 10 feet in front of your office door?! Just a warning to any visitors this week – the Cokeville Meadows office might stink a bit for the next few days.

description of skunk photo by K. Theule on Flickr, USFWS Mountain-Prairie

“Worth the stink? Still not sure…”

Worth the stink? Still not sure … (photo by K. Theule/ USFWS)

(photos by K. Theule/USFWS via Flickr Creative Commons license)

Raccoon Redux

Bald eagle pair scares off raccoon approaching their nest, 17 Feb 2021 (screenshot from PixCams on YouTube)

19 February 2021

On Wednesday night, 17 February just after 7pm, a raccoon scaled one of the branches that holds the Hays bald eagle nest. The mother eagle was on the nest and heard the raccoon coming so she rose up, spread her wings, and scared him away.

Seven years ago a raccoon intruder did the same thing. This one was a little braver.

The raccoon hid nearby, frozen in place, but four minutes later he moved again and the father eagle arrived to help. Two eagles!! The raccoon finally left.

This week’s episode was a raccoon redux of …

See Mary Ann Thomas’ Trib Live report, Pittsburgh Hays Bald Eagles Attack Raccoon Intruder, with video of Wednesday’s raccoon leaving.

Watch the Hays Nest Eaglecam to see what happens next.

(screenshot from PixCams on YouTube)

UPDATE, 19 Feb 2021: The female bald eagle at Hays laid her 3rd egg on 19 February 2021.

UPDATE, 22 Feb 2021: On the night of 22 Feb 2021 a great horned owl knocked the male Hays bald eagle off his roosting perch. The eagle was surprised but unharmed.

Reindeer Can See Hissing Spots On Power Lines

Reindeer in Lappland, Sweden (photo from Wikimedia Commons)

Have you ever been near a power tower whose lines are hissing? We can hear the electrical discharge but we can’t see where it’s coming from. Reindeer can see it!

You’ve probably experienced hissing power lines and wondered about the source of that noise. Sometimes the sound is so bad that it makes us worry. I remember hiking through a power line cut in Pennsylvania’s Laurel Highlands(*) where the lines were crackling. The sound was so spooky that I practically ran to the other side of that clearing!

Pylons in Briar Creek Twp, Columbia County, PA (photo from Wikimedia Commons)

The hissing is a corona discharge, the ionization of the air surrounding the high voltage conductor (wire). As electricity leaks into the air it creates hissing and crackling sounds and flashes in a spectrum we cannot see.

Since 2011 scientists have known that reindeer can see ultraviolet light. They’ve also noticed that reindeer avoid power lines by as much as 3 miles (5km). At that distance there’s no way the animals can hear the lines hissing so what is it? It’s flashing ultraviolet light!

Power companies use UV cameras to see the faults in their power lines so they can fix the leaks.

p.s. It turns out that most mammals can see some level of ultraviolet light. Humans and monkeys cannot.

(photos from Wikimedia Commons; click on the captions to see the originals. *NOTE: The tower photo shows a typical power line cut in Pennsylvania, not the one I ran across!)

Eight Tiny Reindeer?

Santa Claus at Christmas Parade, Toronto, Ontario, 2009 (photo from Wikimedia Commons)

“Twas the night before Christmas when all through the house not a creature was stirring not even a mouse.

… out on the lawn there arose such a clatter, I sprang from the bed to see what was the matter …

When what to my wondering eyes should appear, but a miniature sleigh, and eight tiny reindeer.”

excerpt from The Night Before Christmas, 1823 in The Troy Sentinel

24 December 2020

Miniature sleigh? Tiny reindeer? A human-sized Santa Claus needs a normal sleigh and full-sized reindeer to pull it. Just two reindeer take up a lot of space.

Santa in sleigh pulled by two reindeer, 2007, Torquay, UK (photo from Wikimedia Commons)

Imagine eight of these!

Reindeer to take part in Christmas festivities, Yate, UK 2004 (photo from Wikimedia Commons)

Reindeer (Rangifer tarandus), called caribou in North America, range in size from 5.3 to 7 feet long. Males weigh 350 – 400 lbs, females weigh 180 – 260 lbs. Both sexes have antlers though at different times of year.

Reindeer in Norway (photo from Wikimedia Commons)

These are not small animals. Eight full-sized reindeer and a full-sized sleigh would damage any house they landed on. Santa really needs tiny reindeer. Perhaps he went to Svalbard, a Norwegian archipelago between mainland Norway and the North Pole, to get them.

Like other island species the reindeer on Svalbard have evolved to a smaller size. If you need small reindeer they’re the smallest on Earth, only 50-60% the size of other caribou.

Problem solved.

Christmas lights, Etobicoke, Ontario (photo from Wikimedia Commons)

It’s safe for Santa to come tonight.

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