Bison Biology- Facts About Bison

Bison Anatomy     Bison Ecology     Did you know? (Odd facts)    
Bison Parasitology       Bison Speak (behaviors)         Bison Biology      Buffalo Bones Collection
 Bison’s First Teeth      Bison Aging by Skulls

Are Bison and Buffalo the same?

Milk – Weight –Life Expectancy – European Bison – Pet Behavior’s – Coat Color – Eye Color –Wool –Hair Lengths – Tongue Color –Swimming

Gestation – D.E. – Speed – Five Senses – Horns  – Ribs – Hooves – Diet – Digestive – Organ Weights – Buffalo Chest/Lung – Bison trachea vs Cattle

Bison or American Bison often called ‘buffalo” or American Buffalo. Although it’s not correct, it’s an old habit formed from the first explorers seeing them and referring to them as an Ox type animal.
See: Did you know?   

“Buffalo” is a completely different animal than Bison, people are thinking of the Water Buffalo, also called domestic water buffalo or Asian water buffalo, as a large bovid originating in the Indian subcontinent, Southeast Asia, and China. Today, it is also found in Europe, Australia, North America, South America, and some African countries. 

Water Buffalo, They are known for their milk.

WE DO NOT MILK AMERICAN BISON.
Water buffalo don’t have wool, they are not native here, they are usually black and have skin more like an elephant. They like the waters, where they can be the “Water Buffalo”. 

Are bison native to North America?  Yes!! Our only native grazer.

American Bison are the largest land mammal in North America. As a native species, they play a unique role in the health and diversity of the ecosystem. Bison Ecology

What’s the average weight of bison?

Males or bulls can weigh up to 3,000 pounds, some have weighed more, while the more common range is 1500 – 2000lbs and measure up to 6 ½ feet at the shoulder. They can easily be 9 to 11 feet long. Extremely fast and agile animals. They can run 35 miles an hour and jump a 5-foot fence flat-footed. I saw a 4-month-old calf ‘almost’ clear a 5-foot fence. Just think what they can do with all that size and speed, that with being highly intelligent. Nothing to mess with.

Females or cows are much smaller than their male counterparts. Usually weighing in at 800 to 1200lbs. Some have hit 1400lbs.  They still have horns, chaps, and capes, just not as large as the bulls. They reach a height of 4 to 5 1/2 feet at the shoulder and can be 8 feet long.

Baby Bison

Bison calves weigh 30-70 lbs at birth. Then you’ll have those that have to stand out of the herd and weigh more or less than average. We had a calf last year that weighed 27lbs. She was a tiny thing but has grown up to be as big, if not better than calves her age.

Colonel Dodge’s take on Wood or Mountain Buffalo

Wood Bison vs Plains Bison

The Plains Bison (genus: Bison, species: bison, subspecies: bison)

The Wood Bison (genus: Bison, species: bison, subspecies: athabascae).

Both Wood and Plains are BISON.

How long do bison live?

Charles Goodnight thought they lived forever.  He did believe they lived much longer than what we find today.  “No one knows how long a buffalo will live. I have had a buffalo cow more than twenty-eight years old which produced a calf.”  Charles Goodnight- 1916. They most certainly can live to their late twenties. General Lawton was 26 when he died and  Sir Donald was older than that. The average is about 20 -25 years plus.  Currently, there is a bison in Australia that is in his 30’s. (Jan 2021) Understand also, the younger deaths in bison are not from old age, I’ve heard sickness/worms, broken legs, another bison attack, etc…..then you have competing males during rut, where an older or even young bull can lose his life in the battle. 

“No one knows how long a buffalo will live. I have had a buffalo cow more than twenty-eight years old that produced a calf. ” Charles Goodnight in 1916

European Bison

Lowland and lowland-Caucasian European bison in the Białowieża Forest
ZBIGNIEW A. KRASIŃSKI1, MAŁGORZATA KRASIŃSKA1, JAN RACZYŃSKI2

Dig. 2. Differences in the structure of the head and feet of the Bison bonasus bonasus (A) and the Caucasian European bison Bison bonasus caucasicus (B) (source: Flerov 1932).

A: Biaÿowieÿa European bison – the largest living representative of the genus Bison; height at the withers of an adult bull about 1.85 m, larger than the Caucasian. Feet elongated, almost straight hair all over the body, relatively long front coat, coloration lighter than Caucasian, greyish-brown with ocher-brown tint. The tail is covered with long hair.

B: Caucasian bison – height at the withers about 1.6 m, smaller than the Biaÿowieÿa bison. Hooves short, high and rounded. The coat is curly all over the body, the front coat is much shorter than that of the Biaÿowieÿa coat, the color is darker, brownish-brown with a chocolate tint. Tail covered with short hair with a distinct bunch at the end

Fig. 2. Differences in the structure of heads and hooves of the Biaÿowieÿa ( lowland ) bison.

A: Biaÿowieÿa bison – the largest living representative of the genus Bison, average withers height of a bull c. 1.85 m, higher than in the Caucasus bison. Hooves elongated, almost straight hair all over the body, relaÿvely long hair on the front of the body, colouraÿon brighter than in the Caucasian bison, grey-brown with a hint of ochre-brown. Tail covered with long hair.

B: Caucasus bison – height at withers about 1.6 m, smaller than the Biaÿowieÿa bison. Hooves short, high and rounded. Frizzy hair over the whole body, the front of the body covered with much shorter hair compared to Biaÿowieÿa bison, colouraÿon darker, brown-grey with a touch of chocolate color. Tail covered with short hair, a tuÿ of hair at the end.

Can you have a bison as a pet?

Delving into the notion of a pet bison, understanding ‘pet’ as a domesticated animal kept for companionship rather than work, we can observe that very few bison would enjoy this role. These creatures are inherently social and thrive as part of a herd. In rare instances, a bison might display an easy-going and content demeanor that aligns with traditional pet qualities.

Within our own herds, some groups may be considered pets because there is mutual familiarity between us and the animals. These smaller herds adapt well to routines and respond to sounds like tractor noises, whistles, or feed truck horns. They also recognize the bucket shake as a signal for feeding time.  See Its All About Wesley

More : Unraveling the Secrets of Bison Behavior – Bison Speak

Colors:

Coat color: Typically American bison (Woods and Plains) are born reddish-orange and change to brown at about 3 months of age, maybe even blackish color. I checked with Alaska as they have different light hours than the lower 48, they said; theirs also change at about 3 months. This calf was born black. (Bull Bourne Bison) some of these calves that are born black will grow up to be the common brown bison while others lean towards blackish.

There were several well-known freaks and colour-varieties of the Buffalo “robe,” as the shaggy hide of the animal was called. The “beaver robe” was a rich brown with very fine fur, of these not more than one in ten thousand was found; the “black robe,” oftenest seen in the Mountain Buffalo, was less rare. The “buckskin robe,” of a yellow tinge, a sort of half albine, had little value. There were also the “blue robe,” which was slatey, and the “white or pied robe.” This last was the rarest. One or two in a lifetime was the utmost that any hunter secured. The Indians treasured them as “great medicine.” One which J. Dougherty saw in an Indian hut, “a Bison head very well prepared, which had a white star on the front. The owner valued it highly, calling it his great medicine; he could not be tempted to part with it, “for,” said he, “the herds come every season into the vicinity to seek their white-faced companion.” A magnificent and historical robe of pure white was the special medicine and personal adornment of the great Cheyenne Chief Roman-nose. He wore it in his last fight, when he charged fearlessly at the head of his band to fall in the leaden hail of Forsyth’s troops entrenched on Beecher Island. (Republican River, Sept. 17, 1868.)

Horns are black except for albinos. which have white horns, and pick eyes. Faith, who was born last spring (2020) on the Bitterroot Bison ranch in Missoula, fits all the criteria. She has been DNA tested and she is the real deal. Very rare white bison.

Eye Color

Faith has pink eyes which is indicative of albinos. She will remain white her whole life.

Normally I would say that all bison have black or dark brown

(looking black) eyes, (excluding Albinos).   Years ago we bought a load of young bison from a local. In that load was a poor calf which they called Blondie because his hair color was much lighter than what would be ‘normal’ for a bison. The color was odd, but what was even more odd was his eye color. He had amber or yellow eyes. We didn’t think much about it at the time. For all we knew there could be others out there. But here we are decades later and another popped up. A photographer out of Oklahoma published her pictures from Wichita Wildlife Refuge of a bull with amber eyes. Asking if anyone had ever seen this before. Never forgetting about Blondie …I responded. So, I went on the search for more. These images are the work of Susandiann Photography. She was memorized by this bull. When speaking with Daniel McDonald from the refuge, he said the bull was about 16 maybe older, and was born on the refuge. Wichita Mountains Wildlife is basically a closed herd. In 1958 it was reported that four bulls were brought in from Fort Niobrara National Wildlife Refuge in Nebraska. So where did the eye color come from? (Since this post, this bull has passed on Oct 2021 RIP- Old One Horn)

These two images below are ones I found on the internet. The owners were not able to be found, so I will just show them as what they are. (images found on the internet) The Red (first one) is a European bison or  Wisent. The second looks to be a young Plains bull. 

I have reached out to anyone I can think of for help in resolving this mystery. I will keep you all posted with updates as they become available. One thing they all have in common besides being bison is that all are males. Not much to go on, but……maybe a clue?

Bison Wool  1887-Once a year the great fleece, weighing from 10-14 pounds is shed and its manufacture into thick warm cloth was at one time a regular industry at Winnipeg until it was discontinued by the extirpation of the animals in the adjoining region. 
 1888-Each animal yields from 10 to 12 pounds of this material, and some years ago there was established in Winnipeg a cloth factory for the manufacture of buffalo wool.
Today a couple of sources say 1-3 pounds of down and separated to  8-9 ounces of fine down,  ending up 4-6 after cleaning. 

The Top Notch Hair

– The hide hunters as a rule did not remove the skin from the buffalo’s head, which was covered with long coarse hair that never shed; the hair on some of the old Bulls measured from seventeen to twenty-two inches in length. “General Lawton” from Wichita Refuge measured twenty six inches. 

Just a simple example of a few bison. By no means is it a survey of average measures. (1887-Hornaday)

Here’s another rare trait.

Bison normally have black tongues. 
Recently I was given permission to share this image. Her name is “Pink” and she belongs to 310 Bison Ranch in Jacksonville, Texas. Owned by Steve Unger.              

Bison also do not have upper front teeth. They have a dental pad (covered in thick gum) that helps the clamping-down of the lower incisors and thus the tearing action so that the animal can chew and swallow. There are many animals that do not have upper incisors: Domestic cattle, Domesticated sheep, Domesticated goats, Bighorn sheep, Mountain goats, Elk/Wapiti, Moose, Deer (all species and subspecies), Antelope (all species and subspecies), Gnu/Wildebeest, Pronghorns,  Buffalo (both Water and Cape), Giraffes, Caribou, Reindeer, Muskox.

Do bison swim?

“I watched this bison saunter up to the river’s edge…walk into the water and keep walking until the river became so deep it had to swim…before long, all you could see was the bison’s head, shoulders, and tail! It was quite a sight.” Jerlyn Jones Photography

Many thanks to Legacy Valley Bison of Texas for the use of their pictures of some of their great breeding females.
Home of Big Easy their herd sire.

This is Lazy G Bison Ranch sharing this handsome fella. They are located in Tennessee

How long is a bisons’ gestation period?

Cows give birth usually in the spring after 9 month gestation. Calves will weigh typically anywhere from 30 to 70 lbs. They take no time in getting up, nursing, and ripping around. This cow is 15 years old.

D.E.

Everyone always asks about the white powder. It is Diatomaceous Earth, commonly known as  DE.  You can Read more here: Planet Natural The bison love it! In their perspective, I am giving them a ‘treat’.  I place a bag in their wallow, this is a great place as the bees and other good insects don’t hang out there, but the flies do. 

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How fast can bison run?   Adult bison can run 35-40 mph.

Bison’s Five Senses

Sense of Smell
Bison have an amazing sense of smell, with approximately 300 million olfactory receptor cells – the same amount you would find in a bloodhound. A wolf, by comparison, has about 200 million, and humans a puny five million. Scent molecules that are undetectable to humans carry a myriad of messages to bison. This, coupled with their exceptional hearing, extends their perception of the world outwards for a mile or two at any given time. Even when they are face down in the tall grass, bison are acutely aware of their surroundings. By Graeme McCrady

McHuge thought they could notice a smell at least one mile distant,  Inman (1899: 246) stretched this distance to four miles. Two authors stated that buffalo scented water when it was “five miles or more” away (Garretson,
1938: 46) or “miles distant” (Inman, 1899:247). Vision was evidently not as acute nor relied upon as much as scent.

 Sense of Hearing. Bison have excellent hearing, which they use for communication and to detect potential threats. This keen sense allows them to respond quickly to sounds in their environment, helping them stay safe from predators. Their ears swivel back and fourth allowing them to hear directional sounds. 
 Bison can hear very well and are able to distinguish large objects from a distance of 1 km and moving objects 2 km away. Bison communicate vocally through grunts and snorts. It is likely that chemical cues are used in communicating reproductive states.  Possible Hearing Range 0-21kHz

Bulls may bellow when threatening each other. This sound can be heard up to three miles away. (Meagher 1986) (Buchholtz & Sambraus 1990)

Sense of Taste What’s interesting is that plant-eating animals (herbivores) have way more taste buds than humans – often twice as many. This might seem strange since they eat a pretty limited diet, but there’s a good reason for it. Some toxic plants give off a undesirable bitter taste. So while we humans use our taste buds mainly to enjoy food, wild animals rely on theirs for survival. It’s just another example of how nature has given different creatures exactly what they need to stay alive.

Bison have an incredible sense of taste – about 25,000 taste buds, which is way more than humans (we only have between 2,000 and 10,000).  These taste buds aren’t just scattered randomly in their mouths. They’re carefully arranged in special clusters on their tongue, particularly in areas called fungiform and vallate papillae. Think of these as taste bud neighborhoods, where each area helps the bison get a complete picture of what they’re eating.
BMC Veterinary Research – European Bison

Bulls use a lip curl and tongue (flehmen) to transfer cow’s hormone-packed urine to a receptor organ in the roof of his mouth. (Lott 2002)

Sense of Sight From a half mile, up to 2 miles if its moving. Clarity is my question. Do bison use their other keen senses to help detect what they see? Can they see it, if its not moving?

It’s fascinating how buffalo use their senses. While their eyesight isn’t their strongest suit, these massive beasts can spot trouble from surprisingly far away. Out on the Crow Reservation, they’d catch sight of our jeeps more than a mile out, their heads snapping to attention at the first glimpse of movement.

Here’s what really caught my attention: these buffalo could tell the difference between a lone horse and a horse with a rider. On the National Bison Range, they’d barely glance at horses grazing nearby. But the moment a mounted rider appeared? The whole herd would shift nervously, even if the rider was nearly a mile away on the horizon.

The Hayden Herd taught us something interesting about human encounters. They’d mostly ignore people walking half a mile away, as long as we stayed quiet and the wind didn’t carry our scent. Get too close, though, and you’d see them tense up. But here’s the clever part – if you stayed still or let the shadows of sagebrush hide you, you could sometimes get surprisingly close without them noticing. They’d look right at you, decide you weren’t worth the worry, and go back to grazing.

We even figured out how to approach small groups in plain sight. The trick? Move only when they’re all grazing or looking the other way, then freeze like a statue the second any of them lifts their head. It was like playing the world’s most intense game of red light, green light – with animals that could easily outweigh a car. 
(T.M. Social Behaviors)

Sense of Touch Bison generally do not like to be touched by humans. They communicate with each other by touching, you see a mother nuzzle her calf. One may butt another out of the way. Some bison desensitized by humans may enjoy a good scratching by their human. Bison, with their large, woolly bodies, have a different texture to their skin compared to humans, which affects their sense of touch. 

What size are bison horns?

A bison horn can reach 20 inches long. A bull’s horns are

larger in diameter than a cow’s.

Development of the Horns of the American Bison.
1. The Calf. 2. The Yearling. 3. Spike Bull, 2 years old.
4. Spike Bull, 3 years old. 5. Bull, 4 years old.
6. Bull, 11 years old. 7. Old “stub-horn” Bull, 20 years old.

The buffalo grows to maturity in about three to four years and the age up to six years can generally be told by the horns. A two-year-old bull has horns that turned sharply at the base and stick straight up. Such an animal was called a ‘spike.” At three years the horns are heavier and the tips turn in. At about five years the horns reach their full growth and seen after this they began to splinter off at the point. This continues until some of the older bulls have only short stumps for horns.

The horns of the cows are smaller at the base and they are more curved, also showing rings or wrinkles and thickness with age.

In some cases a bison may break their horn bone or lose their horn cap. The result could be a malformed horn. Fig. 102 & 103.

A lost horn cap means that horn has lost all the growth at the time of the loss. In this case this young bull was just over a year old when he lost his cap. After six months of new growth, you can hardly see the difference in the two horns. At this time there is about three inches of new growth. 

A bison has a large, low-hanging head supported by a prominent hump above the shoulder and massive neck muscles used to plow snow away from feeding sites and uses his weight behind it, in combat. Whether it be another bison, gate, or a YNP tourist. 

How many bones does a bison have? A bison has 213 bones and 32 teeth.  (A Beef Cow has 207 bones) Bison Anatomy (skeletal images and details)

American bison has 14 pairs or 15 ribs? 

1819 Dr. Cuvier of the ménagerie du Jardin des plantes received a young male bison from the United States. The calf was from the Kansas plains and handled by an African American. In 2017 author Charlotte Sleigh wrote in one of her books:

This young specimen was brought to a French menagerie in 1819, accompanied by his African-American keeper. The keeper led the bison by a ring in his nose, and was the only person permitted by the beast – so Saint-Hilaire tells us – to wash, comb and rub him down.

Cuvier claimed that the male bison had 15 pairs of ribs. This has been disputed and repeated several times since even recently I have read on a notable source that the American bison has 14 ribs.

1853  Bison California ” It appears that the Bison will breed with the ordinary race of domestic cattle, against which the aurochs displays the greatest antipathy, though in one respect the latter approaches nearer to the common ox than does the Bison; we allude to the number of ribs, which are thirteen in the ox on each side, fourteen in the aurochs, and fifteen in the Bison. ”  By J.F. LL.D.

I spent the weekend counting bison ribs on internet skeletons, too embarrassed to admit that this information was confusing to me. I don’t recall any of them showing 15 ribs. Is this bison in France be a fluke? One in a million? Or is the one with 14 ribs a fluke? The book(s) that speaks of the 15 ribbed bison, also says there is a specimen here at Harvard.  So I contacted Harvard and they have the No. 91 mentioned in the book mounted. (above image) it appears to have 14 ribs.  (10-12 yo male from Kansas M.C.Z. No. 91)

I reached out to France as well. But, with the Covid struggles, they are unable to look for it at this time. I asked them to keep it in mind because, Dr, Cuvier, being the man he was, I could not imagine him not keeping the skeleton. After all, it was their first American bison. France did breed him, once to a beef cow and both cow and calf died. Cuvier said, after watching the suffering by the animals, he would never try that again.

ETSU: We have counted 8 specimens and they all have 15 pairs.

American Bison generally has 14 ribs and can have 15 pairs

European bison has 14 ribs and has five vertebrae.

Domestic cattle have 13 ribs. 

Bison Hooves:

Bison actually have two hooves on each foot. (cattle do as well)

Wichita Mnt. Wildlife Refuge did some measuring before 1960. They show that it didn’t matter how old the bull was compared to the size of his hooves. While the average was 22.5 inches a bull 15.5 years old measured 24.5 inches and a bull that was only 2.5 years old measured 25 inches. Another bull at 12.5 years old measured 26 inches.

What do bison eat?

Bison eat a wide array of grasses, weeds, and leafy plants, and tree leaves, typically foraging for nine to eleven hours a day. Once the grasses are gone, they will eat alfalfa and baled grasses to get them through the winters if there is no winter pasture mix. Bison producers can be “Grass-Fed” (meaning grass only) and some feed grains a long with their grasses. I will feed mine whole grains from time to time, as a way to move them where I need them. Bottle calves (orphaned calf) I will introduce a molasses-covered processed grain while they are eating grass and still on the bottle. It’s a soft feed and once they get used to it they like it. I do this to get the nutrition into them, there is nothing better than Mom’s milk, but when that is not an option. There are other health benefits to the calf to introduce them to this choice. (medication if need be- made easier) Orphan Calf
In winter, when the snow covers the ground, the bison can and do use their large heads to move the snow and get to the grasses below. In some cases when the snow has fallen too quickly and too deep, it will trap the bison and they can die. (Prof. Dawson made such a discovery in Montana while he was tracking a herd circa 1875)

Bison digestive system:

Bison are ruminants, and have four stomachs (like the beef and milk cows) These chambers allow the bison to break down the feed for better absorption. 
“Bison are also attracted to recently burned areas, therefore, influencing plant diversity. After a disturbance, such as a wildfire, grasses establish before other plant species. Bison prefer these regrowth areas because they have a plethora of grasses available to them without having to graze selectively around woody plant species—woody plants take longer to establish after a disturbance. By grazing in these new grass-dominated sites, bison help increase the local diversity. In other words, a variety of plants have the chance to grow in grazed and burned areas.

Undoubtedly, bison grazing patterns influence the prairie ecosystem. Their foraging is important for plant community structures because woody vegetation can flourish in a grass-dominated landscape. Selective grazing by bison can result in a diverse, heterogeneous landscape of plant species. This preference of grass species can help reduce competition for resources between grasses and woody plant species, certainly increasing species richness and diversity found in the prairie ecosystems.”  (https://www.nps.gov/)

Microbial community composition along the digestive tract in forage- and grain-fed bison

Organ Weights – Bison Bull 1922

On hoof, he weighed more than 1,800 pounds.
Dressed his carcass weighed 800 pounds
Bison hide weight – Hide 150 pounds
Bison liver weight – Liver alone weighed 20 pounds
Bison heart weight – Heart 6 pounds
Bison tongue weight – Tongue 8 pounds

Bison trachea vs Cattle

These two pipes, bison and beef, are of the same age and size animals.

Bison also have larger hearts and lungs than cattle. They can run what seems to be almost forever compared to cattle.

When summer brings on breeding season, I like to watch the massive bulls fighting for the right to mate. A mature bull can weigh more than a ton, and despite their bulk, bison are amazingly quick and agile. Their small rump allows them to spin quickly on front legs, a great defense to dangerous side attacks from rivals. Thick skulls allow bison to endure the head-to-head collisions that determine who is more fit to pass on their genes. These animals can jump over a 6-foot-high fence, run as fast as a horse and keep going for miles. When bison run, their long tongues roll in and out, forcing great amounts of air through a huge trachea to their lungs. What appears to be a sign of total exhaustion actually provides remarkable endurance. Once bison stop running, their breathing quickly returns to normal, and you realize they were hardly stressed.

 

By Brian Kenner who works for the National Park Service. He is the Chief of Science and Natural Resources for Badlands National Park. Bison in the Badlands

JayBird Rietcheck of Hidden Creek Ranch shared these photos of a bison trachea, the bison bull was two and a half years old and weighing 1300 pounds. The trachea is 4 inches across.

“Buffalo cathepsin H” cathepsin /kə-thĕp′sĭn/

Buffalo Chest

“Buffalo Chest” The term “buffalo chest” was first introduced by Schorlemmer et al.in 1984 in the Annals of Surgery, according to a medical publication. “buffalo lung” Although, I found it, “buffalo lung” published in 1978 out of work done at Colorado State University.  I have to wonder if the term ‘buffalo lung or chest” was derived from the Buffalo Lung Center in NY during the tuberculosis, the “white plague’ era. It would not be the first time, buffalo sickness: 1850’s it was used as a term for eating too much and too fast of the buffalo meat (indigestion) , another case was a town named Buffalo where a great portion of the population was sick or died, today it means something completely different. 

The term “buffalo chest” is used to describe a condition where there is a persistent communication between the pleural spaces, a rare anatomical variant also found in bison. The term “buffalo chest” refers to a rare condition characterized by the occurrence of a simultaneous bilateral pneumothorax caused by a communication between the two pleural cavities, typically resulting from an iatrogenic or idiopathic opening in the mediastinum. Many healthcare professionals are familiar with this condition due to a well-known anecdote about Native Americans, who were said to be able to kill a North American bison with a single arrow aimed at its chest, creating a simultaneous bilateral pneumothorax. This ability is linked to the bison’s unique anatomy, which features a single continuous pleural space due to an incomplete mediastinum. If one lung collapses they both do. 

Cattle have a complete mediastinum, which is different from some other animals like bison, dogs and cats that have an incomplete mediastinum. This anatomical feature allows for a more defined separation between the right and left pleural cavities in cattle, sheep, humans. 

But-Autopsies were performed on eight bison, and four indeed were found to have had interpleural communications.  (The Legend of the Buffalo Chest 2021)  Other work in veterinarian  medicine has produced that about 50% of them had gross interpleural fenestrations on autopsy.

The thoracic cavity contains the lungs and mediastinal organs. It has no opening to the outside and is completely separated from the abdominal cavity by the diaphragm. The pleurae, two serous membrane sacs, line the thoracic cavity, one on each side. They form the lateral walls of the mediastinum (in animals such as man and sheep which have a complete one), and are reflected onto the lungs. A complete mediastinum prevents air and fluids passing from one pleural sac to the other. In the dog, however, with its incomplete mediastinum, bilateral pneumothorax will occur if the chest is opened on one side. The pleural “‘space’’ between the parietal and visceral parts of the pleura is occupied by a thin film of fluid, which moistens and lubricates the two pleural layers. The pressure in the pleural cavities is sub atmospheric. Therefore, when-a pleural cavity is opened air enters and the lung collapses.  Dukes, H. H. (Henry Hugh), 1895

The Legend of the Buffalo Chest, Dec 2021

Marielle MJ Blacha ^a, Illaa Smesseim ^d,∗, Ivo van der Lee ^e, Joost G van den Aardweg ^d, Marcus J Schultz ^a,b,f,g, Marja LJ Kik ^h, Linda van Sonsbeek ⁱ, Bernadette S de Bakker ^c, Richard W Light ^j

Study Design and Methods

Results

We were invited to the Rotterdam Zoo, Rotterdam, The Netherlands, to perform an autopsy on one of the North American bison that was euthanized for medical reasons other than respiratory problems. We started with placing chest tubes in both pleural cavities. After inserting almost 4 L of water with methylene blue in the right chest tube, we observed no drainage of water in the thoracic drainage system on the contralateral side of the pleural cavity (Fig 2). We continued with our third method by opening the contralateral pleural cavity and investigated the anterior and posterior mediastinum. We did not observe any blue water in the left cavity (Fig 3), indicating there was no sign of a buffalo chest.

“Dr. Kenneth Throlson was located in ‘a small town in the south of Arizona’ and was reportedly surprised to learn that his observation had been incorporated into the lexicon of thoracic medicine.

Dr. Thorlson had worked with thousands of American bison and observed that about 50% of them had gross interpleural fenestrations on autopsy.  He had also noted that some bison died after sustaining a unilateral thoracic puncture injury – typically via a rival’s horn; interpleural connections explain their demise.  His observed frequency of pleural fenestrations was confirmed by Blacha and colleagues in a small sample [n = 8] of bison.  Importantly, the authors also report that these communications are also present in other mammals such as dogs, horses, cats and rabbits and rightly suggest that their presence in humans are likely underappreciated.”