Category Archives: Mammals

Possum Greets the Night

Possum in the dark (photo from Wikimedia Commons)

24 June 2022

The Virginia opossum (Didelphis virginiana) is a solitary nocturnal animal about the size of a domestic cat and a successful opportunist, so adaptable that it is the northernmost marsupial in the world.

Wikipedia account: Virginia opossum

Every evening Possum wakes up to begin his “day.” In North Carolina, @YardGoneWild’s backyard trail cam watches for his appearance.

Possum greets the night … and then he eats.

(photo from Wikimedia Commons, tweet from @YardGoneWild)

Cute and Confrontational

Red squirrel with peanut (photo from Wikimedia Commons)

30 March 2022

It’s hard to take a bad picture of an American red squirrel (Tamiasciurus hudsonicus). When they pose they look so cute that it’s hard to believe they are asocial, combative and confrontational.

Photogenic red squirrel (photo from Wikimedia Commons)

This sleeping squirrel seems to be saying, “I love you, tree.”

Sleeping red squirrel: “I love you, tree” (photo from Wikimedia Commons)

Ready to fight? Still cute.

Red squirrel looking pugnacious (photo from Wikimedia Commons)

Though they rarely encounter each other — perhaps for their own safety — red squirrels fight when there’s more than one. Most of their battles are a lot of shouting and chasing while the resident squirrel defends his territory.

Defending the midden (food store) is a matter of survival that’s learned in the first year of life. Juvenile red squirrels must find a territory and midden before their first winter or they won’t make it to next spring. Only 22% survive to one year old.

For a few, just 15%, their mothers bequeath them a territory but it still has to be defended. The red squirrels who survive are the most confrontational.

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

Denuded Pine Cones

Central stem of a white pine cone missing all its seed scales, bracts & seeds, Moraine State Park, 24 March 2022 (photo by Kate St. John)

27 March 2022

On a walk last week in Moraine State Park we found a pile of pine cones in various stages of undress. Some were uneaten, some were half eaten and many were stripped bare like the stem above.

White pine cones at the red squirrel’s midden: uneaten to completely gone

The large debris pile called a midden included woody seed scales, pine straw, bract scales, and central stems but few seeds.

Close up of the midden shows many discarded seed scales, Moraine State24 March 2022

It was created while eating the seeds inside the cones.

Anatomy of a woody pine cone (image from Wikimedia Commons)

The midden was made by an individual red squirrel (Tamiasciurus hudsonicus), working alone.

We can know this because of the focus on pine cones, how the cones were denuded, and the sizeable midden. Conifer seeds make up the majority of the red squirrel’s diet and he defends his midden territory year-round against every other red squirrel.

Red squirrels are highly territorial and asocial with very few non-reproductive physical interactions. The majority of physical interactions are in male-female matings and between females and their offspring before the offspring disperse to their own territories. The non-reproductive physical interactions recorded (0.6% of all recorded behaviors in one 19-year study) were all instances of chasing an intruder from a territory.

Wikipedia Account: American Red Squirrel

The red squirrel is small and cute, but always eats alone.

Red squirrel on a tree branch (photo from Wikimedia Commons)

(photos by Kate St. John and from Wikimedia Commons; click on the captions to see the originals)

Candlemas With Groundhog

Candles at Geghard Monastery (photo from Wikimedia Commons)

2 February 2022

Today is Candlemas, Groundhog Day, and the astronomical halfway point between the winter solstice and the spring equinox. This halfway point, called a cross-quarter day, is the reason the holidays exist.

In the astronomical year there are four halfway points between the solstices and equinoxes (green arrowheads in diagram; click on diagram for larger version).

Orbital relations of solstice, equinox (diagram from Wikimedia Commons, annotated for cross-quarters)

February’s cross-quarter day is especially significant because we are coming out of darkness into longer daylight and the growing season. Our ancestors were so excited by the prospect that they created holidays on 2 February to celebrate the halfway point.

For the ancient Celts this day is Imbolc, the beginning of the spring.

In the Christian tradition it is Candlemas, a festival to commemorate the purification of Mary and the presentation of Jesus in the Temple. Candles are traditionally blessed during the celebration.

Festival of Candlemas in Sanok (photo from Wikimedia Commons)

And in Punxsutawney, Pennsylvania it’s Groundhog Day. If the groundhog “Punxsutawney Phil” sees his shadow today (because the sun is shining) winter will go on for six more weeks. If he doesn’t (because it’s overcast) then we’re in for an early spring.

Punxsutawney Phill on Groundhog Day 2018 (photo from Wikimedia Commons)

The sun rose and so did the groundhog to make his prediction. Here is today’s sunrise in Pittsburgh, about 80 miles from Punxsutawney.

Sunrise today in Pittsburgh, 2 Feb 2022, 7:15am (photo by Kate St. John)

Yup, the sun was shining and Phil saw his shadow. Punxsutawney Phil says we’ll have 6 more weeks of winter. Watch the 15-minute celebration here.

(photos by Kate St. John and from Wikimedia Commons; click on the captions to see the originals)

Finding Food in the Cold

Snow scene on 19 January 2022

22 January 2022

I’ve often noticed that in winter there are more birds in the city than the countryside. Though we may not have “quality” birds we make up for it in quantity with large numbers of fruit-eating birds drawn to our ornamental trees.

In the past two weeks hundreds of American robins have been feasting in Oakland. Some of the fruits were inedible until the deep freeze softened them so the robins circled back to finish the Bradford pears last weekend. This week they started on pyracantha berries and the red fruits of this (hawthorn?) tree next to the Cathedral of Learning.

Was half the fruit wasted when birds and squirrels knocked it out of the trees?

Look closely and you can see that deer walked among the fallen fruit. They must have crossed Forbes or Fifth Avenue after dark to browse on the Cathedral of Learning lawn.

Nearby, the sweetgum balls were coated in snow on Monday, all melted by Wednesday.

American goldfinches arrived to pull seeds out of the balls. Some fell on the snow.

And a crow walked by to check it out.

Birds are finding food in the cold.

(photos by Kate St. John)

Black Bears Take To Water

Black bear swimming, Quebec (photo from Wikimedia Commons)

You may remember this news on 23 December 2021: “Three days before Christmas a 260 pound black bear was trapped behind Boy Scout Headquarters in Downtown Pittsburgh where he’d been living for more than two weeks on a wooded hillside.”

How did a black bear end up in a city that’s nearly surrounded by rivers? Did he walk through the East End neighborhoods?

The clue comes from the bear’s first sighting in the Strip District, a neighborhood built on the Allegheny River floodplain. He probably came from the north and swam across the Allegheny.

According to the North American Bear Center in Ely, Minnesota black bears are “good swimmers though their speed and distance limits have not been tested. They can swim at least a mile and a half in fresh water. One bear swam more than 9 miles in the Gulf of Mexico.” (see Quick Black Bear Facts).

Since black bears operate at night to avoid us, we rarely see them swim but they can take to water like ducks when they want to travel or beat the heat. Here’s a black bear swimming in Canada.

During the heat of August 2015 a family of six bears splashed in a backyard pool in New Jersey.

The bears had fun but couldn’t help breaking things.

(photo from Wikimedia Commons, videos embedded from YouTube; click on the captions/videos to see the originals)

Footprints in the Snow

Allegheny National Forest at Beaver Meadows Recreation Area, 12 Jan 2022 (photo by Barb Griffith)

15 January 2022

The sun was shining and the temperature was in the mid 30s when six of us arrived at Beaver Meadows Recreation Area in the Allegheny National Forest on 12 Jan 2022. We were there to find 40 red crossbills (Loxia curvirostra) reported on 29 December. Just one perched in profile would be enough for me. I had to see the beak.

There were few birds in the forest but with an inch of snow on the ground we saw plenty of tracks including the small footprints of meadow voles or white-footed mice, the species that leave most of the little tracks in winter(*).

This one dragged his tail as he bounded across the path, planting his back feet in the prints of his front feet as he hurried from one subnivean hole to the next.

Likely the footprints of a white-footed mouse, Beaver Meadows, 12 Jan 2022 (photo by Kate St. John)

Since meadow voles have relatively short tails my guess is that the print was made by a white-footed mouse, (Peromyscus leucopus) pictured below. Notice the long tail.

We saw many other tracks including:

  • Fox on the lake ice
  • Otters slid on lake ice near their den. A local man helped us with this ID and showed us a photo of the otters.
  • Red squirrels made small highways between trees.
  • Bobcat,
  • Snowshoe hare.

This was my first ever look at snowshoe hare (Lepus americanus) tracks but I recognized the distinctive large hind feet that spread like “snowshoes” to help them walk on snow. (An optical illusion may make the footprints appear to bulge. My boot is at bottom of the photo for scale.)

Snowshoe hare track + tip of my boot, Beaver Meadow Recreation Area, Allegheny National Forest, 12 Jan 2022 (photo by Kate St. John)

Here are two sets of snowshoe hare prints, plain and marked up with notes. In the smaller track the hind feet are just less than 4″ long. In the larger the hind feet are about 6″ long.

Tracks of two snowshoe hares, Beaver Meadow Recreation Area, Allegheny National Forest, 12 Jan 2022 (photos by Kate St. John)
Tracks of two snowshoe hares, Beaver Meadow Recreation Area, Allegheny National Forest, 12 Jan 2022 (photos and markup by Kate St. John)

And here’s the mammal that makes these prints. Snowshoe hares are active at night, dusk and dawn so of course we didn’t see any.

Snowshoe hare in winter at Denali (photo from Wikimedia Commons)

Ultimately we saw 10 species of birds, only 26 individuals, five of which were red crossbills. It was worth the trip for the snowshoe hares. Yes I did see a crossbill beak.

(*) Information on tracks is from Track Finder by Dorcas Miller.

(photos by Kate St. John and from Wikimedia Commons; click on the captions to see the originals)

The Almost Christmas Downtown Dumpster Bear

O my! A real live bear was in Downtown Pittsburgh (photo from Wikimedia Commons)

23 December 2021

In Case You Missed It …

Three days before Christmas a 260 pound black bear was trapped behind Boy Scout Headquarters in Downtown Pittsburgh where he’d been living for more than two weeks on a wooded hillside. He would have gone unnoticed except for the huge mess he left at the dumpsters every night.

Flag Plaza snapshot from Google Street View

The Energy Innovation Center, next door to the Boy Scouts, set up a surveillance camera and caught him in the act.

Hands up! Stop raiding the dumpsters!

Game Warden Doug Berman of the PA Game Commission brought over the bear trap and the rest is history. Find out more in Mary Ann Thomas’ story at Trib Live: Black bear trapped in Downtown Pittsburgh Wednesday Morning and see her video tweets embedded below.

This is how close the bear was to Downtown Pittsburgh’s skyscrapers. I wonder if he’ll miss this view from the parking lot.

The view from Flag Plaza, March 2015 (photo by Kate St. John)

(Christmas bear from Wikimedia Commons, photo of Boy Scout Headquarters at Flag Plaza from Google Street View, view from the parking lot by Kate St. John, tweets embedded from Mary Ann Thomas; click on the captions to see the originals)

Maryland Zebras Are Back On The Farm

Zebras eating hay in Impala Game park Kisumu, Kenya (photo from Wikimedia Commons)

15 December 2021

After four months on the loose the wild zebras of Maryland are back on the farm from which they escaped in August. News of their return was announced on Tuesday 14 December 2021.

Spokesmen for the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service and the Prince George’s County Department of the Environment confirmed that the zebras have been captured, but they could not provide details on when the recovery took place.

Neither the USDA nor Prince George’s County Animal Services were involved in the capture. They said they were notified Monday that the zebras had been recovered and returned to their herd last week. 

Washington Post: Zebras in Maryland caught after months on the run, officials say

WUSA9 tells the story in this 14 December YouTube video.

Click here for WUSA9 video: Maryland zebra story

Read more at WUSA9 or the Washington Post.

p.s. On a happier note click here for a video about three well cared for zebras in Cecil County, Maryland including advice from their owner. (The Cecil County zebras live on the other side of Chesapeake Bay from the “wild zebras of Maryland.”)

(zebra photo from Wikimedia Commons, WUSA9 screenshot from YouTube video; click on the captions to see the originals)

Do They See What We See?

GG looks up from a meal (photo by Chad+Chris Saldin)

30 November 2021

We humans assume that what we see is what everyone else sees, including other species. But this isn’t so.

Peregrines see much finer details at a greater distance that we do. The details don’t blur for them in a 200 mph dive. (Click the link to learn more.)

Tellus in a stoop (photo by Chad+Chris Saldin)

Cats cannot see red-green nor distant details, but they see much better in the dark. Who needs distance vision while looking for a nearby mouse at night? Click here to see photos of our vision versus cats’. Notice the normal vs. red-green-color-blind examples below.

Domestic cat (photo from Wikimedia Commons)
Normal vision vs deuteranopia (red-green color blind) (images from Wikimedia Commons)

White-tailed deer see regular blaze orange as gray but if the orange has fluorescence it stands out for them. Their vision is best in the blue range so that they see well in twilight.

White-tailed deer at Schenley Park (photo by Kate St. John)
Non-fluorescent blaze orange looks gray to deer ( sign from PA Game Commission, Blaze Orange Vest on Amazon)

Birds see ultraviolet light though we cannot. Here’s how we know this and a hint at what birds look like in ultraviolet light.

Do other species see what we see?

No. Birds see more.

(peregrine photos by Chad+Chris Saladin, deer photo by Kate St. John, remaining photos from Wikimedia Commons)