Category Archives: Mammals

40 Years Later: Is Milk Still Radioactive?

Cows drink from drainage trench in Jelno, near Chernobyl, 2005 (photo from Wikimedia Commons)

6 April 2026

40 years ago today, on 6 April 1986, the Chernobyl nuclear power plant at Pripyat in the Soviet Union exploded in the worst nuclear disaster and the most expensive disaster of any kind in history.

At the time, Chernobyl was in the Soviet Union. Five years later, in December 1991, the Soviet Union dissolved and Ukraine and Belarus became independent. In 1996 the radiation exclusion zones spanned three countries: Ukraine, Belarus and Russia. Note how close the power plant was to the Belarus border.

1996 map of Radiation Exclusion and Control Zones due to Chernobyl disaster, CIA Handbook (from Wikimedia)

By 2016 it was safe enough to go on guided tours in the ghost town of Kopachi within the 10km Chernobyl exclusion zone. Here a tour guide shows his Geiger counter reading in Kopachi. (Don’t linger!)

Guide (Sergey) with Geiger Counter in Kopachi Village, Chernobyl Exclusion Zone, Ukraine, 2016 (photo from Wikimedia)

However two years later a 2018 study, published in the journal Environment International, found that cows as much as 140 miles away from the original disaster were still producing radioactive milk. The air was OK but a long-lived radioactive isotope in the soil, cesium-137, is easily taken up by the plants the cows consume and it gets into their milk.

According to the New York Times in 2018, the milk was five times the Ukrainian government’s official limit for adults, and more than 12 times the limit for children.

It is easy to see how this could happen. The cows pictured at top in 2005 were drinking water in a drainage ditch whose purpose was to gather water that cleansed radioactive isotopes from the contaminated soil. The photo caption reads:

Water drainage trenches like this one in Jelno – a village some 300 km away from the Chernobyl Nuclear Power Plant — removes excess water from the peaty soil as a first step. The next step is to diminish the content of radionuclides in the soil by ploughing and introducing mineral fertilizers. Caesium and potassium are chemical twins. Hungry for minerals, a plant will pull out caesium from the contaminated soil but if potassium is in good supply the plant prefers mineral fertilizer. (Jelno, Ukraine, July 2005)

photo caption, Wikimedia Commons

Here is a farm in 2011 within the 30km Chernobyl Exclusion Zone.

Cows on a farm in Pershe Travnia, Ukraine within the Cherbonyl Exclusion Zone, 2011 (photo from Wikimedia)

The 2018 study explained that the problem of radioactive milk could be fixed by adding hexacyanoferrate to cattle feed. This chemical binds with heavy metals, including cesium-137, but it is very expensive.

Unfortunately the problem is probably not being treated. Russia began their full out war on Ukraine on 24 February 2022(*) and there are more immediate dangers now than cancer. 40 years later the milk is probably radioactive.

For more about the Chernobyl disaster, see this documentary video from June 2019.

video embedded from OnDemand News on YouTube

Read more about the study in 2018 in the New York Times or in Newsweek.


(*) p.s. The war in Ukraine is Putin’s effort to regain what the Soviet Union lost due to a combination of factors that included the Chernobyl disaster:

The Soviet Union collapsed on December 25, 1991, due to a combination of chronic economic stagnation, unsustainable military spending, rising ethnic nationalism, and the unintended destabilizing effects of Mikhail Gorbachev’s reforms (glasnost and perestroika). These factors, exacerbated by the 1986 Chernobyl disaster and falling oil prices, led to a loss of central control and the eventual independence of its 15 republics. 

Google AI search result “why did the soviet union dissolve?”

ICYMI: Coyotes Wake Up Glen Hazel “Mom”

Glen Hazel eagle listens to coyotes howling, 14 Mar 2026, 7:50pm
(screenshot from PixCams on YouTube video embedded below)

17 March 2026

ICYMI (In Case You Missed It):

Last Saturday night around 8:00pm the sound of sirens in the Monongahela Valley near Glen Hazel prompted a nature sound below the eagles’ nest.

The female eagle, nicknamed Mom, was sleeping and ignoring the sirens (“it’s just more of that human noise”) but she woke up and watched when coyotes answer the siren’s wail. PixCams moved the camera to see if he could find the coyotes, but no.

video embedded from PixCams on YouTube

It should be no surprise there are coyotes on the wooded hillside near the eagles’ nest. They have been in the Pittsburgh city limits since at least 2003, my neighbors saw them in Greenfield in 2017, and I regularly see coyote scat in Frick and Schenley Parks.

Coyote scat in Schenley Park, May 2025 (photo by Kate St. John)

Some people are afraid of coyotes but are they dangerous?  Not to us humans but myths abound, apparently borrowed from our myths about wolves. 

Some of our fears, not based in modern experience, seem to be bred-in-the-bone from prehistoric time. For example, some people automatically fear snakes even though they will never encounter them. This makes sense as an ancient fear spawned from early humans’ experience in Africa.

Legend has it that St. Patrick drove the snakes out of Ireland(*). Does anyone in Ireland fear snakes anyway? Interesting question.

Happy St. Patrick’s Day!

Three 4-leaf clovers (photo from Wikimedia Commons)

(*) In fact, Ireland was already snake-free when St. Patrick arrived. All the snakes died during the Ice Age and never came back.

Magic in the North Woods: Wildlife at Voyageurs

Fisher at Ipswich River in 2012 (photo from Wikimedia Commons)

27 February 2026

Enjoy the magic of the north woods in this video from @voyageurswolfproject on Instagram.

This video was captured on a trail cam by the Voyageurs Wolf Project, a Univ of Minnesota research project that studies wolves in and around Voyageurs National Park. The park is in “The Arrowhead” of Minnesota on the U.S.-Canadian border in a huge wild area that includes Voyageurs, Superior National Forest, and the Boundary Waters Canoe Area (BWCA) in the U.S., and Quetico Provincial Park in Canada.

Map of BWCA and surrounding national parks and forests from Wikimedia

There are many familiar animals in the video but you might not recognize the animal standing on its hind legs at the beginning. It’s a fisher (Pekania pennanti), an omnivorous member of the weasel family that is only the size of a large house cat. To put its size into perspective, here’s a porcupine and a fisher near each other.

screenshot from PA Game Commission fisher reintroduction video

Fishers were extirpated from Pennsylvania when we cut down our forests but have been reintroduced by the PA Game Commission. This 33 minute video tells their story in PA.

Lucky Day

Elephants at Khulu Bush Camp, Zimbabwe, 26 Jan 2024 (photo by Kate St. John)

13 February 2026

Today is Friday the 13th, a day that some people consider unlucky but there are many good things about it:

It’s always a good day for elephants when they find food and water in a safe place. Sometimes it’s in a reliable location where they eat every day such as the Khulu Bush Camp in Zimbabwe where I visited two years ago (January 2024).

Elephants at Khulu Bush Camp, 26 Jan 2024 (video by Kate St. John)

And sometimes they just luck out by being at the right place at the right time. Like when this orange transport truck broke down in South Africa.

May you have a Lucky Day!

How to Forget Your Troubles: Sea Otters!

Sea otter mother with pup on her belly, Morro Rock (photo from Wikimedia Commons)

6 February 2026

With more snow on the way today in Pittsburgh we need something to take our minds off our troubles. Sea otters are the perfect solution.

Sea otters live among kelp because they eat the organisms that eat kelp. They dive to gather sea urchins, sea stars, sea cucumbers, crustaceans, a variety of mollusks, snails and bivalves. Then they float on their backs with their food set on their bellies as they open and eat their prey.

embedded YouTube Short from @Expeditions

In addition to using their bellies as the dining table, sea otter mothers carry their babies on their bellies. They take their babies everywhere.

video embedded from YouTube Nature on PBS

So cute!

p.s. If you want to see sea otters in the wild, here’s where you’ll have to go.

Range of the sea otter (map from Wikimedia Commons)

Squirrel Appreciation Day Coming Soon

Eastern grey squirrel in St. James Park, London, Nov 2006 (photo from Wikimedia Commons)

14 January 2026

One week from today we will celebrate Squirrel Appreciation Day … or rather, “some of us” will celebrate. My husband has heard people complain about squirrels and asked, “How many members in the squirrel fan club? Three?”

If you have bird feeders, squirrels are often the mammal you love to hate.

An acrobatic eastern gray squirrel reaches Marcy Cunkelman’s feeder, Nov 2010 (photo by Marcy Cunkelman)

On the other hand they are very creative and fun to watch, especially when they have to solve problems to get to the feeder.

Some people put out food specifically for squirrels because they are so cute.

American red squirrel stops to take a look at the camera (photo from Wikimedia Commons)

And there is nothing cuter than the small nocturnal southern flying squirrel.

Southern flying squirrel at a bird feeder (photo from Wikimedia Commons)

Find out more about squirrels and their special day at this vintage article:

City Raccoon Snouts Show They Are Domesticating

Raccoon closeup (photo from Wikimedia Commons)

12 January 2026

In Case You Missed It (ICYMI), this study made a splash in November/December:

A new study from the Univ of Arkansas finds that raccoons living in urban areas are physically changing in response to life around humans—an early step in domestication.

The study lays out the case that the domestication process is often wrongly thought of as initiated by humans—with people capturing and selectively breeding wild animals. But the study authors claim that the process begins much earlier, when animals become habituated to human environments.

Scientific American, 14 Nov 2025: Raccoons are showing early signs of Domestication

Did you know that domesticated mammals have physical traits that set them apart from their wild cousins? “Domestication syndrome” includes whiter or brown patched fur, floppy ears, shorter muzzles, smaller teeth. The image below is a partial table of those traits. (Click the image for a larger version. Click on the image caption to see the complete table.)

partial Table 1 from The “Domestication Syndrome” in Mammals: A Unified Explanation Based on Neural Crest Cell Behavior and Genetics

Raccoons are not listed in the table but they are making physical strides on their own and might be domesticated some day. At the University of Arkansas researchers viewed thousands of raccoon photos from iNaturalist and found …

We use raccoons as a mammalian model system to test whether exposure to human environments triggers a trait of the domestication syndrome. Our data suggests that urban environments produce reductions in snout length, which are consistent with the domestication syndrome phenotype

— (boldface added) Tracking domestication signals across populations of North American raccoons (Procyon lotor) via citizen science-driven image repositories

Shorter snouts!

CP24 in Toronto — where there are so many raccoons that the animal is an unofficial mascot — interviews the study’s author in this video.

video embedded from CP24 Toronto on YouTube

For more information, see this article in Scientific American and the original Univ of Arkansas study paper at Spring Nature Link.

Confuse Mongoose Moms, Get a Fair Society

Banded mongooses in a pile (photo from Wikimedia Commons)

8 January 2025

Imagine a society in which all the mothers become pregnant around the same time and, when it’s time to give birth, they all gather in a large room and give birth on the same night. It’s dark, there are lots and lots of babies. All the women help each other and help the babies. Soon no one is sure which baby is her own biological child but it doesn’t matter because all the mothers raise the young together. In the shuffle each mother finds a baby she wants to cuddle and care for and that child, regardless of whether it’s the one she birthed, is the one she will escort into adulthood.

That’s a pretty good description of banded mongoose (Mungos mungo) society.

A group of banded mongooses (photo from Wikimedia Commons)

Because of their birthing strategy banded mongoose moms are confused about biological kinship. Does this lead to a fairer society? Do the best equipped mothers cuddle the pups who need the most care?

In 2021 scientists from the University of Exeter and the University of Roehampton decided to find out. In their paper at Nature Communications: A veil of ignorance can promote fairness in a mammal society, they wrote (paraphrased), “In his 1971 book A Theory of Justice, American philosopher John Rawls argued that fairness in human societies can be achieved if decisions about the distribution of societal rewards are made “from behind a veil of ignorance” which obscures the personal gains that result.

Working with seven groups of mongooses in Uganda, they manipulated the birth weights of pups by giving some, but not all, of the pregnant mongooses extra food. After giving birth, the well-fed mothers doted on the smaller pups born to the underfed mongooses by feeding, carrying, protecting, and grooming them more often than their own, larger pups. “

We predicted that a ‘veil of ignorance’ would cause females to focus their care on the pups most in need” rather than their own offspring, Exeter evolutionary biologist Michael Cant said in a press release. In doing so, he adds, mongoose mothers minimize the risk that their future offspring could one day face a disadvantage—while evening [leveling] the playing field for the whole colony.

Science Magazine, June 2021: Mongoose mothers help their colonies thrive—by forgetting which pups are theirs

Confuse mongoose moms about kinship and you get a fair society.

p.s. Banded mongooses are closely related to meerkats. This one poses like a meerkat.

Banded mongoose standing like a meerkat (photo from Wikimedia Commons)

And here’s where banded mongooses live.

Range map of Mungos Mungo from Wikimedia Commons

Orcas Scratch an Itch in the Shallows

Orca at Johnstone Strait, Canada (photo from Wikimedia Commons)

7 January 2026

Orcas (Orcinus orca), sometimes called killer whales, are the largest member of the oceanic dolphin family and like their cousins, bottlenose dolphins, they shed their skin continuously.

Shedding is so important that those who live in frigid polar water cannot shed effectively so algae builds up on their skin. To solve this Antarctic orcas make very fast 5,000-mile round trip migrations to tropical waters off the Atlantic coast of South America where their skin sheds quickly. It takes so little time to get a whole new skin in warm water that they are back home in only 40 days.

Not all orcas need to visit the tropics for their skin health. Resident orcas on the Pacific coast of British Columbia, Canada use a scraping technique to shed skin. On 2 January (human) residents of Sunshine Coast, BC were treated to this unique behavior when a pod of orcas swam for 20 minutes in shallow water, scraping their bellies on smooth submerged rocks like these.

Waves rolling over round rocks at French Beach, BC, Canada (photo by James Wheeler via Flickr Creative Commons license, souvenirpixels.com)

The resident orcas are so well known that were easily identified.

The group of whales has been identified as northern resident killer whales (NRKW) and the A5 pod, which comprises three different families, according to Jared Towers, the executive director of Bay Cetology.

CBC News

Orcas scratch their itch in shallow water.

p.s. Here’s a little more background.

(a) We’re familiar with what orcas look like when they jump in deep water.

Orcas jumping near Unimak Island, Alaska (photo from Wikimedia Commons)

(b) The Sunshine Coast district in British Columbia, Canada is north of the city of Vancouver and across the strait from Vancouver Island, BC

Location of the Sunshine Coast, BC, Canada (embedded from Google Maps)

(c) Resident orcas are also common in the vicinity of Vancouver Island, BC.

Orcas near Vancouver Island, BC, Canada (photo from Wikimedia Commons)

River Otter Rapid Transit

River otter at the ice shelf, Big Stone NWR, Minnesota (photo from Wikimedia Commons)

2 January 2026

December was snowier than expected and the New Year started with a line storm of blowing heavy snow that quickly ripped across Pennsylvania in the wee hours of New Years Day.

Snowfall always makes travel difficult, except perhaps for river otters who move faster than usual by sliding in the snow. Their tracks look odd until you know what they’re doing.

River otter step-and-slide tracks in snow, Seedskadee NWR (photo from Wikimedia Commons)

Run, slide, run, slide.

video embedded from Barrett Hedges on YouTube

This technique was especially useful when two otters escaped a zoo last winter. Here’s a description of the video that follows.

Mar 26, 2025, Two river otters, Louie and Ophelia, weaseled their way out of their Wisconsin zoo enclosure last week during a winter storm, appearing on security camera footage cavorting across the snow, as the search continued Tuesday. The NEW Zoo & Adventure Park said the two North American river otters escaped through a small hole that they enlarged in a buried fence, and their flight was quickly noticed by zookeepers on their morning rounds. (Video provided by NEW Zoo & Adventure Park via Associated Press)

Otters slip through snow as they escape Wisconsin zoo
video embedded from MLive on YouTube

River otter rapid transit!