Natural History Notes

The Bison Chronicles (Part 1): 1973–1997

Rob Denkhaus, Nature Center Manager


[Records and other documents often provide a fascinating glimpse into an organization’s history. That has been the case with the Fort Worth Nature Center & Refuge’s bison herd. Looking back through numerous records and applying some deductive reasoning, we can trace the origins of the herd, how it has grown, and its expanding importance to the Nature Center. This article was first published in the JanuaryMarch 2008 issue of Bluestem News. It has been edited for length and clarity.]


The Fort Worth Nature Center & Refuge’s bison herd made its debut on November 9, 1973, with the arrival of three 2.5-year-old bison—a bull and two heifers—donated from the Wichita Mountains Wildlife Refuge.


Not long after, on May 21, 1974, one of the females gave birth to the Nature Center’s first calf (see photo above)—a female—probably sired by another bull prior to the heifer’s arrival at the Refuge. The Nature Center’s second calf appeared a year later in May 1975. Using available documents, it appears this calf was also a female, bringing the herd’s composition to 1.4.0 (animal husbandry shorthand for one male, four females, and zero unknowns).


Records indicate that 1977 proved to be an eventful year. Two calves—probably a male and a female, according to various sources—were born on April 25 and May 12. Sadly, on July 23, the Nature Center was forced to deal with its first bison death. The necropsy report doesn’t indicate a specific cause of death but mentions a bacterial infection and approximate age at death (six years old), which means the heifer that died was one of the original three animals from 1973. The report also states that she was lactating and caring for a calf. The orphaned calf wouldn’t have been weaned and probably managed to nurse from the other lactating heifer. This isn’t common among bison, but it can occur. The death of the heifer reduced the herd to six (2.4.0), but another calf was born on September 18. It isn’t reported, but if my assumptions are correct, this calf was the first second-generation bison on the Refuge.


A drought must have been a problem during 1977 as the November issue of Bluestem News describes the bison range pond (just south of the Prairie Dog parking area) as being dry and staff hauling water to a trough on the south side of the range. This trough, while no longer functional, can still be seen along the south fence line of what is now known as the East Pasture.


In addition to causing water shortages, the drought must have had a negative impact on the amount of forage available to the bison herd. In an effort to reduce the size of the herd, a “six-month-old calf” was donated to the Fort Worth Independent School District Outdoor Learning Center in November 1977, once again resulting in a herd of six bison (2.4.0).


Nothing specifies which calf was donated, but the age implies either the April or May 1977 calf. Logically, the orphaned calf was probably the one donated; it would have been smaller, less hearty, and, therefore, easier to capture and move. A Fort Worth Star-Telegram article (November 7, 1977) mentions that an employee from the Outdoor Learning Center tried unsuccessfully to capture a calf but would try again later. I haven’t located any information to confirm or deny success at a later date, but I did locate a photo (see photo below) that shows someone attempting to dart a calf during that time period.


There are no bison herd changes reported in 1978, but 1979 saw two births (April 27 and the “first week of May”), increasing the herd to eight (2.4.2). This must have caused quite a stir among the staff at the time because they frequently reported that the bison range could support only five to six bison without considerable supplemental feeding.


A very limited budget, coupled with the impacts of the earlier drought, called for immediate reaction. On October 9, 1979, Nature Center staff requested permission from the Fort Worth City Council to sell four bison (“two-year-old bull, two-year-old heifer, and two calves”) to Dan Coates of Weatherford for $1,000. I believe these animals would have been the May and September 1977 calves plus the calves born earlier in 1979. The sale was approved but stipulated that Mr. Coates had to supply portable corrals (to capture the animals), his own trailer, and his own employees to conduct the capture and loading. I am pleased to say that we no longer have those kinds of stipulations because we have the equipment, facilities, and trained personnel to carry out these types of operations.


The sale reduced the herd to a much more manageable 1.3.0, although there are indications that the bull that was sold was not the two-year-old. It appears likely that the bull that was sold was actually the original bull from the Wichita Mountains Wildlife Refuge. While this wasn’t described in the official request to sell the animals, it makes sense when looking at later herd management. Since the two-year-old was at least a year away from reproductive maturity, the number of new calves would be limited the following year.


Most of the supporting evidence for my theory comes from the 1980 records. First, no calves were born in 1980, not surprising if a young, unproven bull was herd sire. Second, a tragedy was reported on the evening of November 24, 1980, when a staff member discovered that the herd bull was dead. The cause of death was unknown until later that night when a veterinarian performing a necropsy found that the bull had been shot with a high-caliber weapon. The bison killer was never found, but a number of newspaper articles were published about the incident. Tom Wood, Nature Center director at the time, was repeatedly quoted in the newspaper articles stating that this was the Refuge’s only bull and that purchasing a replacement was not possible because of budgetary constraints. Another donation from the Wichita Mountains facility would have to wait until the following fall because they had already moved all of their surplus animals.


As is often the case, a generous individual stepped forward. Mr. Leo Potishman, who had a bison herd near Granbury, donated a yearling bull on December 1, 1980. This bull, after reaching reproductive maturity, became herd sire and offered the first chance to diversify the genetics of the Nature Center’s herd, turning a tragedy into an opportunity.


An interesting side note regarding the bull that was shot is that Jim Diffily and Bill Voss from the Fort Worth Museum of Science and History came out to the Refuge the following day and assisted the staff in skinning the bison (see photo below). It’s believed that the hide and skull are still part of the museum’s collection. The meat was donated to shelters to feed those in need.


The dead bull’s line lived on through three calves born in 1981 (female on April 14 and two females on unspecified dates), increasing the herd to seven (1.6.0). Due to the new bull’s age, no calves were produced in 1982 or 1983.


In 1984, when the new bull would have been five years old, his first calf was born. The calf—another bull—was born June 27, which is about two months later than usual. No clues are available to determine which heifer was the mother, but it is obvious that only one of three mature heifers produced that year. The herd was now up to eight (2.6.0).


The herd was again at the level that prompted the 1979 sale of surplus animals, and I am certain the staff was afraid they would be faced with three additional calves in the spring of 1985. Only one female calf was born on April 6, 1985, which would have increased the herd to nine except that earlier in the day, an adult heifer had been found dead of unknown causes. Unfortunately, I have not been able to locate any details on the death, but I assume that means no foul play was suspected.


The herd still numbered eight in February 1986 when the City of Fort Worth agreed to sell three bison (heifer, heifer calf, and yearling bull) to Mr. John McRae of Ponder for $2,900. The animals sold would have been the bull calf from June 1984 and the 1985 calf and her mother. There is no mention of any stipulations regarding the capture and transport of the animals, but I assume Mr. McRae had the same arrangements as Mr. Coates in 1979 (see photo below). It is interesting to note the increase in bison value in seven years, most likely a result of the growing interest in bison ranching for meat production and use in training cutting horses.


Following the sale, the herd was reduced to five (1.4.0). The remaining bull was the 1980 donated bull. It is much more difficult to determine specifically which females remained because of incomplete records, but it is possible one of the original heifers still lived on the Refuge.


Record keeping over the next decade was spotty at best. A few births were documented (unknown on October 16, 1987; a female on April 26, 1990; a female on May 7, 1991; and two unknown calves in May to June 1992), but no deaths, sales, or other reductions were reported. If these records are comprehensive for the time period, the herd totaled ten bison (1.6.3) by the end of 1992.


The blockbuster news for the era came on December 12, 1995, when the City of Fort Worth transferred ownership of the bison herd to the Friends of the Nature Center. This agreement has led to a vast improvement in facilities, equipment, and food supplies to better manage the herd.


Bison herd management in the next decade was well documented. Detail is available to the extent that I can tell you that former Nature Center Manager Suzanne Tuttle fed the herd four bales of hay and 150 pounds of range cubes on October 1, 1997. This level of detail is fantastic except that one piece of information is missing…the number of bison in the herd when these later records began. From staff memories and from what I can track through documentation, the herd began 1997 with 15 animals (2.5.8), including the sire bull (known as Tao, who I believe was the unknown 1987 calf) and his son, Medicine, who was born in 1993. The two bulls used to engage in some impressive shoving matches while trying to establish or maintain dominance and breeding rights.


Five breeding-age heifers were in the herd, including one aged heifer known as Mom. I have no idea how old Mom was at the time, but it is possible she was one of the calves from the mid to late ‘70s. The rest of the herd was composed of a mixture of eight immature bulls and heifers.


Two calves, both female, were born in 1997—one on an unknown date and the second on November 5. Three additional unknown calves were born in 1998 (May 26 and 28 and June 2), bringing the herd total to 20 (2.7.11). These five young animals were the first to benefit from the Friends’ first major investment (other than food) in bison management—our Powder River handling equipment. This equipment enabled the staff to capture and restrain the bison, which then permitted veterinary care for the first time. The handling equipment also facilitated trailering bison and led to the first sealed bid auction in 1998.


[Part 2 of The Bison Chronicles—1998–2017 will follow in in the next issue of Natural History Notes.]



Photo Captions: All photos credited “FWNC&R Staff Photo”


First calf 1974: 1974. The Nature Center’s first calf, a heifer, was born on May 21, 1974.


Darting calf…: 1977. An orphaned calf is tranquilized prior to being donated to the Fort Worth Independent School District Outdoor Learning Center.


Skinning bull…: 1980. After a poacher shot the herd bull, Fort Worth Museum of Science and History staff members collected the hide and skull for educational exhibits, honoring the animal welfare community’s wish to “maximize the gift” of any animal found dead or that must be killed for some reason.


1986 Bison sale: 1986. Early surplus bison sales lacked the quality capture and handling facilities now found at the Nature Center.

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