Bison Romance

During North America’s early spring, a reddish-orange creature emerges.  Within minutes of its appearance, the newly-born bison calf rises and begins expending pent up energy.  Its movements constantly watched over by its mother, the largest animal on the North American continent.  Colloquially known as a “red dog,” this little beastie weighs in from 30 to 70 lbs [1] upon its debut, a far cry from its future weight (approx. 2000 lbs for males and 1000 lbs for females), easily attained within a couple of years.  Some may consider this newly arrived entity as “cute.”  They would be deceived.  For this “cute-ness” scampering around in the spring air will transform into potentially the greatest source of animal-induced injuries to humans in North America.  It will scoff at bears, coyotes and mountain lions.  Oh my!!  Of course, wolves are a different matter.  Hunting in packs, they can take down an adult bison. So what is the origin of this “cute” beastie?

Bison Calf – “The Cute Little Beastie”

                Its genesis begins slightly more than 9-1/2 months [2] prior to its emergence. During the summer months of July or August romance rumbles and shakes the earth.  The females of the species begin to gather with the up-until-now aloof males straggling in from their own groups to join the females.  Before now, the bulls do not communicate much with other bison.  Prior to the breeding season, they are usually off on their own or in small groups, being content to graze.  However, with the onset of the breeding season, the rut, the bulls become more communicative.  One may believe only courtship of the female occurs during the rut.  But the male has a tough job ahead.  He not only has to win the attention of a receptive female, but he also has to manage other bulls.  The bull will seek out a female and stay with her.  This behavior is called tending.  While doing so, he must also ward off other bulls by fighting and threatening.

                Males will vie for the females.  Even though a bull is tending a cow, it is not entirely a foregone conclusion this will be the mating pair.  Other bulls may threaten to replace the tending bull.  The one who dominates will take over the tending, but will then also have to ward off anxious bulls looking to mate. But fighting requires much energy which is also required for breeding.  So, the bull will generally threaten first in order to conserve energy.  Threatening may begin with bellowing, a sound the bull makes, which to the undiscriminating ear, may sound like thunder off in the distance.  The intruder may also bellow in return, and if the bellowing competition escalates, as typical of males, the sounds become louder and the bravado more expressive.  During the bellowing, the bulls may paw the ground or wallow [3] [4]. Bison often will lie down in a barren depression and role back-and-forth, throwing up dust.  Though there are other reasons as well for this behavior, it is often used in the bull’s threatening behavior.

                During challenges, wallowing may also engage a strange phenomenon. But males of other species sometimes exhibit bizarre behavior when attempting to win over the female as well — nothing really new here.  A threatening bull may urinate in a wallow and then roll in the moist ground.  The reason is not fully understood.  Dale Lott, a naturalist, speculates the testosterone level is being signaled to the challenging bull.  As the bull uses up physical resources, muscle begins to metabolize with the metabolites entering the urine, which can be detected by the conditioned nose of the challenger.  The opposing bull will know if fat is still being burned and if muscle is still intact [5] of the threatening bull, allowing the opposition to determine if he has the resources to continue the fight against the threatening bull.

Bison Wallowing

                If bellowing and wallowing do not work, then the males will begin to posture.  There are two types of posture: head-to-head and broadside.  Head-to-head posture precedes a charge in which the two bulls will run straight at each other.  As they approach one another, either one or the other may submit by turning  away or they will bang heads.  If they approach slowly, they will engage in a behavior called “nod-threatening”.  The two bulls will stand close enough to each other to reach the other with their horns by turning their heads aside.

                In the broadside posture the bull will keep himself broadside to his opponent and raise his head a little as well as arch his back and bellow.  The idea is to show he is not to be messed with.  However, this posture usually does not lead to a fight.  The broadside and the nod-threatening postures demonstrate the lengths bulls will go to forewarn each other.  The issue is efficiency.  Perhaps even more than offering protection to the herd, producing calves is the bull’s prime directive.  Breeding requires energy, and the bull, instinctually driven, attempts to mate as much as possible to produce  as many calves as possible.  Fighting seriously reduces the bull’s energy.  Further, fighting and breeding burn up fat and muscle mass, which have to be replaced between the end of the rut, which may last into September, and the onset of winter if the bull is to survive the winter [6].

Bulls Going Head-to-Head

                Before the tending of the female and the subsequent efforts to win his prize, the bull first selects a female.  Cows come into heat sometime during the rut, and will only be in that state for about two days.  Cows only release one egg at a time.  Achieving fertilization requires attracting a suitable mate and be willing to mate, which means changes for the cow.  When she comes into heat, the vulva becomes swollen and oozes mucus and lymph, signaling to the bull she is ready to mate.  The bull will wander through the herd inspecting each cow to determine which ones are ready to mate.  After inspecting, the bull may curl his lip.  Lip curling is a complex expression.  The bull stretches out his neck, holds his head level, distends his nostrils and curls back his lips.  This occurs after examining the cow’s vulva or sniffing her urine [7].  The cow’s urine will indicate how close she is to ovulation.  The bull detects this through the vomernasal organ, which has an opening in the roof of the bull’s mouth.  This organ seems specialized for analyzing the female’s urine [8].

Bison Lip Curling

                Often the cow rebuffs the bull by the swing of the head, a thrust of horns or sometimes just a good swift kick. After selecting a cow, and if the bull has not been dissuaded, the courting begins.  During courting, the bull stands parallel to her side, warning off intruders which may even include the cow’s previous calf or yearling.  The pairing may last only a few minutes if a more dominant bull intrudes and displaces the tending bull.  Or the pairing could last one or two days.  In either case, the tending bull will move on to another cow, being driven by the bull’s prime directive.

Even though the bull may seem dominant, but the cow rules the courtship. Typically the bull follows behind her.  If he tries to direct her in a particular direction, she can easily dodge him and wander off on her own.  He is resigned to follow her.  Eventually, the herd leaves the pairs behind.  The cow may try to rejoin the herd, but the bull will move to block her, which she can easily evade. Or she may also go for a higher ranking male.  She, too, has a prime directive to breed the best calf.  After all, she only has one shot each season.  So she must choose wisely, and is more receptive to older bulls who have survived winters, predators, disease and battles.  Older bulls have been tested and have been found worthy.  If, however, she stays, she has chosen him.

The bull utters brief panting sounds as he approaches the cow, warning her.  First advances are typically repelled but the bull will be insistent.  His intentions are made known by standing and swinging his head.  Eventually he will attempt to put his chin on her rump, which, in response, she will evade.  He may try to climb upon her, only to have her slip out from under him.  But once receptive, the cow will allow the bull to mount.  He uses his chin as leverage to lift himself onto her rump, leaning his head against her side and pressing his forelegs around her.  After insertion, the thrusts last only 4 to 10 seconds.  Then he either drops off or releases his forelegs so the cow can walk out from underneath him.  The copulation may harm the cow.  Her flanks may have bloody wounds from the bull’s front hoofs striking and rubbing her. The moment of copulation usually attracts the attention of younger males who will follow the couple afterwards.  But the tending bull will stay with the cow, warding off other suiters to prevent them from also mating with her.  This ensures the tending bull’s seed is successful fertilizing the egg and not replaced by the seed of another.  Eventually though, the tending bull will move on to attempt to mate with other cows [9][10]. 

Bison Mating

Nine and-a-half months later, the fruition of the bison romance occurs, as a reddish-orange little beastie emerges.  Upon birth the cow licks, pulls away and even eats the membranes entangling the calf.  After disposing of these membranes, she licks the slimy wet coat of the newborn.  Meanwhile oxytocin, a pituitary gland hormone, has flooded her brain stimulating her endearment of this new creature, which she will nurture and protect [11]. If the cow is only three years old, then this is most likely her first calf.  Females breed when 2 years old and have their first calf at 3 years old.  Cows can live 20-25 years, having a calf each year [12]. 

The cycle completed, the newborn “red-dog”, if male, will repeat the fine tradition of seeking and tending a female, threatening and fighting challenging bulls, and mating with as many females as possible.  If the little beastie is female, she will enter into the honored role of controlling the mating process and producing off-spring, and nurturing the next generation.  And so the cycle continues, sustaining the herd and ensuring the survival of the species.

End Notes:

[1] Retrieved from https://www.doi.gov/blog/15-facts-about-our-national-mammal-american-bison.

[2] The average gestation period is 9-1/2 months.  Retrieved from https://bisoncentral.com/faq. 5-Jul-2019.

[3] McHugh, Tom. 1972. The Time of the Buffalo. University of Nebraska Press. 191-195.

[4] Lott, Dale.  2003. American Bison: A Natural History. University of California Press. Berkeley. 14-18.

[5] Lott. 9.

[6] McHugh. 192-193.

[7] Lott. 15.

[8] Lott. 20-21.

[9] McHugh. 192-195.

[10] Lott. 15-17.

[11] Lott. 29.

[12] Bisoncentral.com

Brucellosis: Crying Wolf?

Just north and outside of Yellowstone National Park, deep snow covers the ground and bitter March winds blow through the pines. Because of the adverse winter conditions in the Park, the bison have had to seek better grazing. Following the easily traveled snowmobile trails, they have wandered out of the harsher conditions of the late winter park.  Using their heads to plow away snow to uncover the buried grass, a small group of bison graze.   Only the crunching of the snow under their hooves, the occasional snort of exhaled breath, and their rhythmic breathing along with the occasional bird song and the moaning of the pines swaying in the wind can be heard.  Suddenly, a shot rings out!  A bison cow goes down!  Then another shot and another!  Two more cows are hit.  One stumbles and then drops.  The other runs back toward the park bleeding profusely.  The rest have already bolted for the safety of Yellowstone.  The wounded one makes it back to within the confines of the park, but has stopped, exhausted, drained.  She tries to take another step in the deep snow, but cannot.  She lies down and slowly dies.  No one comes for her.  A few days later, her scavenged carcass will be found.  Back at the killing grounds, the hunters are celebrating.  They have thwarted another incursion of the feared bison onto the bison’s natural grazing habitat.

            So why fear the bison outside of Yellowstone Park?  They do not attack humans or other animals unless they feel threatened. They do not devastate the land as they graze. So why such hostility toward them as illustrated above, which is a fictionalized account of what has happened and continues to happen.  Bison roaming outside of the Park into Montana are either hazed back into the park or killed.  Hazing involves rounding up the bison and herding them back into the boundaries of Yellowstone or into a quarantine pen, which inherently causes trauma for them.  But herding of bison is difficult.  Killing is easier.  But why slaughter an animal carrying the last known wild bison genome?

            The Montana ranchers claim bison threaten the cattle herds with the disease brucellosis.  Brucellosis, a bacterial infection (B. abortus), causes abortions and still-births in cattle, bison, elk, bear, deer, etc.  If a brucellosis outbreak would occur and spread through a cattle herd, financial devastation could result for the rancher.  As a side note, any losses, ironically, would be covered by government subsidies. 

            Upon closer examination of the circumstances and history of brucellosis in bison, the claim of the ranchers and the Montana Livestock industry strike one as a smoke screen.  One would think that science should be driving the claim, but politics and profits seem to be the drivers.  The USDA has threatened the state of Montana with the loss of Montana’s brucellosis-free status, which permits shipment of untested cattle across state lines.  The loss of such status means the ranchers would have to pay to have the cattle tested prior to shipment, which incurs additional costs. To ensure no risk of cattle infection the eradication of brucellosis has taken on a zero tolerance approach, giving absolute priority to achieving a zero risk level for cattle infection [1].  In addition, since almost no brucellosis can be found in American cattle herds, the USDA has expanded its efforts to eradicate the disease. The US Dept. of Agriculture has turned its attention to eradication of brucellosis in wild animals.  Thus, agencies whose funding depends on the USDA are recruited into the cause [2].  The eradication of brucellosis has become politicized with agencies increasing their power and funding by joining the crusade to rid the wild animal population of brucellosis.  The crusade, of course, includes the method of slaughter as well as vaccination.  However, the slaughter only seems to be restricted to bison; other wild life are not included. The slaughter of the Yellowstone bison arose, then, out of fear and political expediency, not science.

            Brucellosis probably arrived with infected cattle imported by Spanish settlers into Mexico.  Sometime prior to 1917 infected cattle were introduced into the Greater Yellowstone Area [3][4] with the disease spreading to the bison.  But the transmission of brucellosis from bison to cattle has never been established.  The actual transmission path would have to be through the ingestion of infected birthing materials or from an aborted fetus.  Thus, bison bulls, calves, yearlings and non-pregnant bison cows would not pose a threat. Furthermore, infected pregnant bison females will only pass infected material in her first pregnancy since after the first pregnancy, the uterus develops protection, preventing infected material being shed in subsequent births [5]. 

In order for brucellosis to be passed on to cattle cows, the cattle cows would have to lick or eat the discharged reproductive debris.  But bison abortions or still-births are rare.  If they do happen, the most likely time is winter when cattle are not present.  Cattle are unable to withstand bitter winters and are not grazed near Yellowstone until June.  By this time, the bison would have returned to the park [6].  But even should there be aborted or birth materials in June or later, the brucellosis bacteria cannot survive warm weather or direct exposure to sunlight.  Besides, predators and scavengers would all but guarantee fetuses or infected reproductive material would not persist beyond mid-May [7]. Thus, the possibility of cattle cows contacting infected material is remote.

Recent studies have shown that bison are not the primary reservoir of the brucellosis bacteria.  The bison were once considered to be the primary source because of high levels of B. abortus.  But examining the extent and transmission characteristics in other wildlife has shown elk to be the primary source of B. abortus.  Even though elk have a lower level of B. abortus, they are more numerous and widespread than bison.  Bison rarely move outside of conservation areas and are subject to rigorous management practices that limit migration, making comingling with cattle almost impossible.  In contrast, elk are allowed to freely range, and make long-distance migrations between summer and winter grounds, increasing the probability of contact with livestock.  Genetic studies have confirmed this, demonstrating elk to be the likely source of infections, not bison [8].  This begs the question: Why are elk, the primary source of brucellosis infections, allowed to roam free and bison are not?  The revenue generated from elk hunting may have something to do with it.  Revenue from elk hunting activities amounts to approximately $11 million annually for the state of Montana alone [9].

            Hazing and killing of bison that have roamed outside of YNP are not the only methods employed to placate the fears of the ranchers. With the state of Montana and the USDA insisting, bison are periodically rounded-up and tested.  About 45% of the bison test positive for long-term antibodies.  Using a positive test as proof of infection, the bison is slaughtered.  But another test is performed after the bison has been killed to determine if actual bacteria are present.  Comparing these two tests reveals a drastic difference.  Very few slaughtered bison have the actual bacteria.  The bison, then, are being slaughtered simply because they have developed immunity to brucellosis [10]. The control of brucellosis is a “no holds barred” approach when it comes to bison. Of course, the slaughter includes both bulls and cows. But why slaughter the bulls who cannot transmit the disease, and are essential for breeding? The logic to the slaughter remains elusive unless it is understood as arising from an unjustifiable fear.

            In response to the brucellosis eradication efforts in bison a number of viable solutions have been offered.  The Buffalo Field Campaign (www.buffalofieldcampaign.org) has offered several. These include:

  • Develop herd management plans that adjust cattle grazing dates which would eliminate transmission potential;
  • The Greater Yellowstone Area could be exempted from the OIE certification process by keeping cattle out of the area.
  • The state of Montana could develop risk management strategies for domestic cattle that allow free roaming bison [11].

            In light of the evidence–genetic studies, the migration and grazing habits of bison, the elk herds as a primary brucellosis reservoir, the transmission dynamics, and the testing results—and the offered solutions, why does the slaughter of the bison continue? Based on the above, it appears to be a result of the efforts of the livestock industry in Montana to maintain political control, using the fear and the paranoia over brucellosis as the means to maintain that control.

[1] Lott, Dale F. 2002. American Bison: A Natural History. University of California Press. Berkely, CA. 111

[2] Callenbach, Ernest. 1996. Bring Back the Buffalo: A Sustainable Future for America’s Great Plains. Berkeley. University of California Press. 281-283. These actions of the USDA continue to this day.  Confirmed by Darrell Giest, Buffalo Field Campaign, in an email to the author dated 15-April-2019.

[3] Callenbach. 134-139

[4] Kamath, Pauline L., Foster, Jeffery T., et. al. Genomics reveals historic and contemporary transmission dynamics of a bacterial disease among wildlife and livestock. Nature Communications. 11-May-2016.

[5] Yellowstone Bison and Brucellosis: Persistent Mythology.  Retrieved from http://www.buffalofieldcampaign.org/yellowstone-bison-and-brucellosis-persistent-mythology. (3/30/19).

[6] Callenbach. 280.

[7] Yellowstone Bison and Brucellosis: Persistent Mythology.

[8] Kamath.

[9] Willcox, Louisa. 8 March 2017. The Last Stand for Yellowstone’s Bison.  Retrieved from https://www.counterpunch.org/2017/03/08/the-last-stand-for-yellowstones-bison/

[10] Yellowstone Bison and Brucellosis: Persistent Mythology.

[11] Yellowstone Bison and Brucellosis: Persistent Mythology.

Bison Air Support

When we think of the Great Plains and the prairies, we most likely envision a landscape of grasses rolling on to the horizon.  But the skies above those grasses are as much a part of the ecosystem as the land itself.  Upon the air currents circulating over the land, birds, insects, and bats fly searching for food, nesting materials, and escape routes from predators.  These same air currents disperse seeds over the plains and prairies, increasing plant diversity.  Though the aerial species may be above it all, they, like any air force, are dependent upon ground support.  Key to that support is the bison.

                In tall-grass prairies, lupine, a flowering plant, has diminished along with the demise of the bison.  Lupine flourishes with a mix of shade and sun.  Without the bison, the trees and woody shrubs of the oak savannah [1] overshadow the other plants, depriving the lupine of much needed sunlight,  resulting in a decline of lupine across the northern prairies due to loss of habitat.  Much of that loss resulted from converting the prairies into farmland.  But in the remaining prairie, tree and other woody plant cover has suppressed lupine growth.  In the past, when bison were present, they maintained a reduction of woody plant cover.  They kept woody shrubs and trees out of the area by rubbing their horns and bodies against the shrubs and trees, and by causing minor soil disturbance, the bison had a significant impact [2].

Wild Blue Lupine
An Oak Savana

                Among the lupine, flitter approximately 50 rare species of butterflies.  One in particular is the Karner Blue Butterfly [3], listed as endangered in 1992.  The Karner relies on lupine as both a food source and a place to lay their eggs.  The bison create and restore the open habitats of the oak savannah prairie, which the lupine and the butterflies desperately need.

The Karner Butterfly

                Re-introducing the bison to one area, the Sandhill State Wildlife Area in Wood County, Wisconsin, [4] bore out this relationship among the butterflies, the lupine and the bison.   Since the return of the bison, a significant recovery of both lupine and the Karner has occurred [5].

                Birds of the Great Plains and the prairies benefit from the bison as well.  While bison graze the wealth of perennial grasses, they are often surrounded by a small flock of birds, including brown-headed cow birds (also known as buffalo bird), starlings, and magpies.   The grazing stirs up insects out of the grasses, providing an easy feast for the surrounding birds.  In addition, the birds get free rides, hitching on the backs of the bison, consuming the insects found in the bison’s hair.  The bison amenities, though, not only offer meals.  During inclement weather, the backs of bison also offer protection against the elements. 

The Brown-Headed Cow Bird
Birds and Bison

                While grazing renders insect-hunting easier, bison-grazing creates heterogeneity of grasses, resulting in a range of forage heights  from very low (heavy grazing) to high grass (no grazing).  These conditions promote a variety of bird species from those who nest only in low vegetation to those who nest only in high vegetation and those species whose nesting preference is somewhere in between. In contrast, cattle graze uniformly in regard to vegetation height, leaving forage at a mid-height which reduces habitat for those avian species that require either low or high vegetation [6].

                Amid the grasses where the bison roam, shallow soil depressions can be found.  For various reasons bison roll in the soil, creating wallows.  Filling with water during storms, wallows provide habitat for a variety of insects, frogs, and birds.  For the birds, the water-filled wallows provide drinking water and a staple of insects.  Dry, the wallows offer habitat for such birds as the sharp-tailed grouse and the burrowing owls [7].

                Aerial support though, also involves providing materials for ground cover.  Bison hair and wool, as well as dung, [8] are used in the construction of nests.  Hair and wool provide insulating and water-repellant materials and more.  Nests lined with bison wool suffer less predation because the hair, serving as olfactory camouflage, masks odors of the nest site [9], warding off predators.

                A significant example of the importance of the bison to bird species would be the burrowing owl, which has been declining for many years due to the loss of habitat and the control programs of prairie dogs and ground squirrels.  Prairie dogs are just as essential to the Great Plains and prairies as the bison are.  A full discussion of the significance of prairie dogs is beyond the scope of this article, but in respect to the borrowing owl, the prairie dog burrows provide ideal habitat for the burrowing owl.  The bison’s contribution, especially in tall-grass and mixed-grass prairies, comes through their grazing.  The bison make the prairie dog towns possible.  Prairie dogs will not live in tall-grass since it is less nutritious and hides predators.  But bison grazing keeps the tall-grass short enough to promote prairie dog towns [10].  

Once a burrow becomes available, the burrowing owl brings together the burrow and bison dung into a unique arrangement.  Using bison dung to line the burrow, the burrowing owl ambushes dung beetles.  Attracted by the feces, dung beetles are an important food source for adults and developing nestlings [11] (Perhaps this is why owls are considered wise, because they know their shit).

Burrowing Owl

Even in death the bison provide for the aerial life of the plains.  Scavenger birds such as crows, ravens, magpies and turkey vultures feed on the carcasses. Typically such scavenger birds as ravens and magpies along with turkey vultures will show up first.  Initially, these birds feed on carrion flies, since they cannot break through the hide.  Later, perhaps after spotting the ravens and magpies, bald and golden eagles may join the feast. But even the eagles may have difficulty tearing open the hide and generally depend on other predators such as wolves to perform that task. Once opened, the eagles are able to rip apart the innards of the carcass into smaller chunks, creating serving sizes for smaller mammals [12].  Indirectly, the carcasses, as they decay, nourish the plant life which in turn offers habitat and food for birds and butterflies.

From flittering butterflies to soaring and burrowing birds, bison support a variety of invertebrate and avian species which populate the skies above the plains and prairies.  The decline of the bison and the conversion of the Great Plains and prairies into farms, ranches and concrete has devastated the indigenous avian, riparian and lepidopteran species. The avian species of the Great Plains have seen significant population decline [13], while the many butterfly species of the surrounding prairies also appear on the threatened or endangered species lists.  Fortunately, such efforts as those of the American Prairie Reserve in Montana and the Sandhill State Wildlife Area in Wisconsin are making strides in recovering many of those species.  But the questions will be:  Will these efforts be expanded? How will we act upon what we have discovered?  How quickly will we act?  Some time ago Joni Mitchell wrote a song called Big Yellow Taxi, which starts out:

They paved paradise
And put up a parking lot
With a pink hotel, a boutique
And a swinging hot spot
Don’t it always seem to go
That you don’t know what you’ve got
‘Till it’s gone

It would seem these words are still apropos in regard to the ecosystem of the Great Plains and the surrounding prairies.

____________

[1] An oak savannah is a plant community where the oak tree is a dominant component but the density of the oaks is so low it allows grasses and other vegetation to become the actual dominants of the community. Retrieved from https://oaksavannas.org/.

[2] Bison Bellows: Bison Bolster Endangered Blue Butterfly Recovery. https//www.nps.gov/articles/bison-bellows-8-4-16.htm

[3] Named by the novelist Vladimir Nabokov. 

[4] In 1962 12 bison were donated to the Sandhill State Wildlife Area.  The current herd consists of 15 bison on 260 acres.

[5] Bison Bellows: Bison Bolster Endangered Blue Butterfly Recovery

[6] Heidebrink, Scott. Bison Restoration Manager. American Prairie Reserve. Email to author dated 3/8/19.

[7] Retrieved from https://blog.nwf.org/2016/06/wildlife-that-depend-on-wild-bison/

[8] Coppedge, Bryan R. Patterns of Bison Hair Use in Nests of Tallgrass Prairie Birds.  The Prairie Naturalist. 41: December 2009. 110-115.

[9] Baily, James A. American Plains Bison: Rewilding an Icon. 2013. Sweetgrass Books. Helena, MT. 46. and Coppedge

[10] Lott, Dale F. American Bison: A Natural History. 2002. University of California Press. Berkley, CA. 128.

[11] Coppedge

[12] Lee, Barbara. Decomposition.  Montana Outdoors. 2014. 21-22. Retrieved from

[13] Brennan, L.  A., and  W.  P.  Kuvlesky. 2005. North American  grassland  birds:  an  unfolding  conservation

crisis?  Journal of Wildlife Management 69:1–13.

Dung Cake and Feces Pie: Yum!

In architecture there is a stone upon which the whole structure depends.  It is known as the keystone.  More precisely keystone is a masonry term, and is the stone without which the structure collapses. 

Bison are a keystone species for the Great Plains. But specifically for the bison and the Great Plains what does this keystone look like? How does it work?  Perhaps a good place to start is where the poop hits the trail.  Usually when we hear “the chips are down,” we understand life is not going so well; but that is not true for the grasslands of the Great Plains.  When the chips are down, a veritable feast ensues.  Life is great for a host of microbes, insects, fungi and plants, which themselves present a delicious offering to other species.  Who would think dung could be so sweet?

We on the so-called upper echelon of the food chain look down on the unassuming dung pie.  Casting a disdainful glance on the heap, holding our noses as we pass, we hurry by to avoid further sensibility damage.  Our minds formulate a four-letter word, which, if spoken is a “naughty word.”  In our passing, though, we fail to see a dung beetle working feverishly on its claim.  It, in turn, has ignored us, so intent on its business; perhaps it is thinking in Cheech and Chong style: “This is some good shit man.” 

So what does the world of a bison dung pile entail? To understand this unique world its origin story must be told. In this case, the genesis of bison dung begins in the hidden regions of the bison digestive tract and in particular in its rumen, the first chamber of the bison’s four-chambered digestive system. In the rumen microbes aid the digestion of plant matter. The microbes provide enzymes which facilitate the breakdown and metabolism of the plant matter. These microbes and undigested plant matter, then, pass through the bison’s digestive system and deposit as feces on the soil. This is the fundamental means of nutrient flow for the grasslands. The average bison produces 10-12 quarts of dung in a day, providing a valuable source of nitrogen, phosphorus, calcium, sulfur and magnesium for microbes, plants and critters [1].

 In our walk by, and side-step of, the odious heap, we probably perceive the pile of blended nutrients to be just that: a static plop of poop.  However, we would be so wrong.  A diverse population of parasites, hosts, predators, prey, flies, dung beetles, wasps, earwigs, springtails, mites, etc. inhabit this aroma-rich world.  Not a static world, the dung world bustles with activity varying as it ages. The drying pile attracts different residents at different times.  Flies which may have been hovering around the bison hoping not to be snatched by a cowbird are ready to swoop down on the freshly dropped excrement as soon as it hits the ground, swarming over it like…well…like flies on poop.  The flies close to the herds literally have the drop on flies further away. Flies and other insects not close to the herds will come later following a spoor of wind-blown odors [2].  The flies test the surface of dung-world until it is dry enough to lay eggs.  The fly-infested bison chip can produce up to 3000 flies in over two weeks, providing a banquet for box turtles, bats and birds.

Dung beetles, bussing in flies and mites, come later, searching out bison dung. In our passing we probably did not consider that dung piles also vary in nature.  Poop is diverse, and dung beetles are selective.  Indeed the dung beetle populations have declined since the introduction of livestock because they cannot find just the right plop of poop.  The decline of the bison brought the decline of the industrious dung beetle.  This has reduced the ability of natural systems to cycle nutrients and decompose fecal matter, impacting the function of the Great Plains ecosystem [3].  Perhaps we should be required to go to Dung Diversity classes to address our dung-bias. 

During our next walk past a bison pile, after our Dung Diversity course, we pause and now notice our little Cheech and Chong  friend (Well, at this point it’s probably not the same beetle, but for the sake of this discussion we are pretending that it is).  We see it is perhaps a tunneler or roller  beetle working feverishly, burying the fresh manure into the soil.  From what we learned in our course, we realize what a great service these beetles offer.  Our little friend, by burying the excrement, moves nitrogen and carbon directly into the soil and activates microbial activity.  Microbes convert the nitrogen into ammonia which is essential to plants [4].

But dung-world is not a quaint, peaceful world of maggot nurseries, nutrient farms, ammonia factories and waste management facilities.  A ruthless insect-eat-insect environment exists.  Beetle and wasp larvae eat or kill maggots.  One kind of beetle can take away so much of the dung pile nothing is left for other insects.  The tumble bug will take a large mass of dung, roll it into a ball, deposit its eggs inside and then roll the ball of dung to a nesting site [5].

Insects, microbes and plant material are not alone in composing the fecal cake.  Seeds consumed during grazing, pass through the bison digestive tract and find a home in dung-world.  Bison feces contain an abundance and diversity of plant seeds, making bison an important dispersal agent [6].  Without the bison, the range and diversity of the grasses of the Great Plains and prairies is greatly reduced.

By providing crucial residence for invertebrate life, nutrient transformation processes for plants, and transportation means facilitating grass diversity, bison dung sustains the life of the Great Plains.  When the bison roamed the Great Plains and surrounding prairies in the millions, those ecosystems had an efficient means of replenishment and sustenance.  Now, without wild free-ranging bison grazing over vast stretches, without a keystone species, what will become of the Great Plains?  Not to mention: where will our little dung beetle friend find a home?

_______________________________

[1] A Healthy Prairie Relies on Bison Poop. Bison Bellows. http://www.nps.gov.

[2] McHugh, T. 1972.  The Time of the Buffalo. 233.

[3] Bison Bellows

[4] McHugh, 234.

[5] McHugh 234.

[6] Rosas, Claudia A., Engle, David M., Shaw, James H. & Palmer, Michael W. See dispersal by bison bison in a tallgrass prairie. Journal of Vegetation Science 19: 769-778. 2008.

Legal Status of the American Bison

On May 9, 2016, President Obama signed the National Bison Legacy Act, recognizing the American Bison as the national mammal of the United States.  Alongside this noble gesture, the Senate has repeatedly passed resolutions since 2012 recognizing the first Saturday of November as National Bison Day to encourage the celebration of the historical, cultural and ecological significance of the American Bison.   Though these recognitions were long overdue, they have not led to any significant improvement in the status of the American Bison.  Indeed the National Bison Legacy Act states that the “North American bison is adopted as the national mammal of the United States” (HR 2908) and makes clear that the Act will have no effect on any policy, plan, or regulation:

Nothing in this Act or the adoption of the North American bison as the national mammal of the United States shall be construed or used as a reason to alter, change, modify, or otherwise affect any plan, policy, management decision, regulation or other action by the Federal Government (Sec. 3 (b) Rule of Construction, HR 2908).

Though its importance is not over-looked, the Act, essentially, stands as symbolic gesture.  The wild bison need more than just rhetoric.  They need legal recognition at both the state and federal levels.

                The International Union for Conservation of Nature (IUCN) Red List of Threatened Species concluded that the American Bison is a Near Threatened species [1].  This designation results from the circumstances of the bison.  To persist, the species is dependent on ongoing conservation programs.  All mature bison occur within active management programs, which, if stopped, would result in the bison qualifying as a Threatened species. Geographically widely dispersed populations prevent natural movement and opportunities for the generation of genetic diversity.  Approximately 97% of the bison population is managed for captive, commercial consumption, while very few herds are managed for conservation purposes, and none are managed for public interest.  The number of adult bison in wild-free-ranging and semi-free-ranging extends from 11,000 to 13,000 with only 4 herds over 1000 individuals.  These low numbers, and the lack of free-range which would allow the subpopulations to inter-breed and strengthen genetic diversity, nearly qualify the bison to meet the criteria for Vulnerable Species. The conclusion of the IUCN Red List regarding the likelihood of wild bison increasing depends completely on conservation interventions.  Without the National Parks, Refuges or Sanctuaries the wild American bison is not likely to survive [2].

                Given this assessment by the IUCN and our seeming desire as a nation to honor the bison through such recognitions as the National Bison Legacy Act, one would think serious efforts would be underway to ensure the future of wild free-ranging bison.  Though a few efforts by individuals and groups have been made to improve current legal conditions in a few states affecting bison, no political will exists, either at the state or federal levels, to address the IUCN’s dire warning. (Continue to part 2)

From the Brink to the Foothills

Tucked into the Absaroka range of eastern Yellowstone, bordered by grasslands guarded by a forest of pines, flows Pelican Creek, feeding Yellowstone Lake. As the creek approaches the lake, the sulfur-scented steam, arising from fissures around the lake, greets the stream.  Skinning his kill of bison in this valley, in the winter of 1894, a  poacher is unaware he has been spotted by a US Cavalry unit. After following snowshoe tracks, a US Cavalry scouting unit comes across six bison scalps.  Continuing their tracking, they spy the poacher pursuing a herd of buffalo.  After the kill, and as the man scalps the bison, they capture and arrest him.  Fatefully, the scouting party, along with the poacher and the evidence, encounter a party of conservationists, one of whom is Emerson Hough, correspondent for Forest and Stream, who will report and publish this incident[1].

 As the report repeated throughout the newspapers of the day, it aroused the public and initiated more serious attempts to save the bison.  These attempts include three major efforts: numerical recovery, domestication and agribusiness practices, and the more recent ecological/sustainable approaches.

Prior to this incident, efforts to save the bison from extinction were mostly words of warning and legislation with no enforcement. Warnings of the coming demise came as early as 1820. Major Stephen Long, after seeing bison killed on an expedition, advocated for a law to protect the bison.  In 1843 John J. Audubon gave his own prophecy of the coming extinction of the bison: “Like the Great Auk, before many years the buffalo will vanish.  Surely this should not be permitted”[2].  Others as well, added their voices, including George Catlin (American painter and traveler), Josiah Gregg (explorer and naturalist), and Joseph Leidy (a prominent scientist of the day).  Despite the warnings, no action was taken either by the US Congress or the states during the 1850s, proving once again prophets have no honor in their own countries (cf John 4:44).  Not until 1864 was any law even passed, and then it was by the Idaho Territory, not the US Congress, protecting the bison.

However, this law was limited, making it illegal to hunt between February 1 and April 1[3].  In 1875 Nebraska passed a law as well, but by then not many bison were left to protect.  The US Congress, in typical fashion, did not get on board until public opinion arising from Hough’s report provided the impetus.  In 1894 the first US buffalo protection law, introduced by Rep. John F. Lacey of Iowa, was signed into law by President Grover Cleveland[4]. The first serious steps toward recovery of the bison had begun.

After this, came a variety of laws to protect the bison and implement more intentional recovery efforts.  Fortunately, individuals and families, farmers and ranchers, such as Charles Goodnight of Texas had collected bison calves to start small herds. All together these small herds amounted to less than 1000 bison remaining, and from these came the seed stock for starting and expanding new herds.  One significant owner of a few bison was the New York Zoological Society which initiated the American Bison Society in 1905, and provided the bison for the creation of the Wichita Mountains National Wildlife Refuge herd in southwestern Oklahoma[5].  The US Fish and Wildlife Service created another important refuge for bison, the National Bison Range, which originated with bison from the Flathead Indian Reservation[6].  A small herd of bison in Yellowstone survived.

All the early legislation and recovery efforts were laudable, for numerical recovery was absolutely essential to pull the bison back from the brink of extinction.  But adverse consequences resulted despite the good intentions and actions.  All throughout the recovery efforts from the early 1900s through the 1970s stood the question: How do you manage a species to bring it back from the brink of extinction?  (continue to part 2)


Bring Back the Buffalo Nation

The Great Plains: a vast region of North America stretching from the northwestern region of Canada to Mexico; from the eastern slopes of the Rockies into the Midwestern states of the United States. To the early pioneers and settlers who moved into this region it was perceived as a desolate grassland which became mythologized as the Great American Desert: a forbidden place.  For these people, who only knew of European livestock and crops, this was an unsupportive land; essentially a desert to cross to get to more promising and more familiar surrounds.  But this region was far from unsupportive.  It teamed with life. It supported many nations of Native Americans. 

The Great Plains is home to a variety of flora and fauna.  It hosts tallgrass in the east, short-grass in the west , mixed-grass in-between and medicinal plants such as yarrow and purple coneflower. Sparrows, grouse, meadow larks, prairie falcon, hawks and owls fly in its skies and nest in its grasses. Elk, pronghorn, coyote, wolves, grizzly bear, and other fauna roam and graze throughout this land.

Then there was Pte Oyate (Lakota language); the buffalo nation/people. The buffalo, or more precisely Bison bison- the North American buffalo (the words buffalo and bison are used interchangeably), spread out over this vast region and beyond as a great sea.  When Lewis and Clark explored this region in the early 1800s, it is estimated the herds numbered around 23 to 26 million.  This sea of brown reached from Alaska to Mexico; from the Great Basin of Nevada to Appalachia.  But by the late 1800s, this sea had all but dried up. Estimates place about 800 buffalo on farms and ranches and another 23 found in Yellowstone when the slaughter was brought to an end. Though bison were killed off by the US Army in its war against the Plains Indians in an effort to remove their food supply, the vast majority of the buffalo were killed for economic reasons.  Their hides were used for clothing and industrial belts (rubber had not been invented yet).   Their bones ground up for fertilizer and their tongues considered a delicacy by people.  And then there was just the sport, those who came to claim a trophy. But the extermination of the buffalo was not the only loss to the Great Plains. The buffalo and the diverse flora were replaced with a monoculture of crops and livestock foreign to the Great Plains, such as wheat , corn, and cattle; all of which, unsuited for the Great Plains.  The diversity of flora and fauna had been lost; significantly contributing to such events as the Dust Bowl years. For the Great Plains is an ecosystem in which all flora and fauna are interconnected.  With the loss of the buffalo, replacement with cattle, and the introduction of foreign crops, the ecosystem of the Great Plains had been significantly disrupted.  One of the keystone species to that ecosystem is Pte Oyate, and to restore the Great Plains our brothers and sisters of that nation must be brought back. (continued to part 2)