Pryor Mountain Mustang

Pryor Mountain Mustang

Pryor Mountain Mustang stallions
Distinguishing features Small, compact, good bone, very hardy
Alternative names Pryor Mustang
Country of origin North America
Horse (Equus ferus caballus)

The Pryor Mountain Mustang is a substrain of Mustang considered to be genetically unique and one of the few strains of horses verified by DNA analysis to be descended from the original Colonial Spanish Horses brought to the Americas by the Spanish. They live on the Pryor Mountains Wild Horse Range located in the Pryor Mountains of Montana and Wyoming in the United States. They are protected by the Wild and Free-Roaming Horses and Burros Act of 1971 and managed by the Bureau of Land Management (BLM). Because of the unique genetic makeup of the Pryor Mountains Mustang herd, equine geneticist Dr. E. Gus Cothran concluded in 1992 that "the Pryor herd may be the most significant wild-horse herd remaining in the United States."[1] Dr. D. Phillip Sponenberg, equine veterinarian at Virginia-Maryland Regional College of Veterinary Medicine, agreed, noting, "[These animals] don't exist anywhere else."[2] This herd was the subject of the 1995 documentary film Cloud: Wild Stallion of the Rockies and its sequel, the 2003 documentary film Cloud's Legacy: The Wild Stallion Returns.[3]

Contents

Characteristics

The Pryor Mountain Mustang has a very specific conformation type. The animal is generally 13 to 15 hands (52 to 60 inches, 132 to 152 cm) high, with an average of 14 to 14.2 hands.[2][4][5] The horses weigh 700 to 800 pounds (320 to 360 kg) on the range, and more if raised in captivity.[5] The animals exhibit a wide range of solid colors, including bay, black, chestnut, dun, grullo, and blue or red roan.[2][6] Buckskin coloring is rare but does occur, and pinto coloring can be minimally expressed.[6] However, the majority of colors are dun or grullo.[5] Nearly all the horses on the range exhibit primitive markings such as dorsal stripes, transverse stripes across the withers, and horizontal "zebra" stripes on the back of the forelegs.[2][4][5] The Pryor Mountains horse's body is heavy, with strong bones.[5] Manes and tails tend to be long, and the horse's winter coat is very heavy and often curly.[5] The head is convex or straight (the "Roman nose" identified by horse breeders), with wide-set eyes, hooked ears, and a broad forehead that tapers to well to the muzzle.[2][5] The front teeth meet evenly, the upper lip is usually longer than the lower, and the nostrils are small and crescent shaped.[5] The neck is medium in length, and most of the animals have only five lumbar vertebrae (an anatomical feature common in primitive horses)—although some have a fifth and sixth vertebrae which are fused.[5] The horse's shoulders are long and sloping, the withers are prominent, and chests are medium to narrow in width.[5] The croup is generally sloped, and tail-set is low.[2][5] The hooves are ample and very hard.[5]

Pryor Mountains Mustangs exhibit a natural Ambling gait.[2][5] The horses are generally intelligent, strong, and sure-footed, and exhibit great stamina.[5] Like all feral horses, they generally avoid human contact, are distrustful, and are easily spooked. However, once they are familiar with an individual, they can exhibit a strong social bond with that individual.[5] Pryor Mountains horses can be broken and ridden, and trained to do any task a domesticated horse can perform.[5] Trained Pryor Mountains horses have a calm temperament, and are alert on trails.[5]

The horses form bands or "harems," in which a single stallion mates and controls a group of about six mares.[2] Another eight to 10 "bachelor" stallions accompany the band at a distance, hoping to win control of it from the stallion or mate with mares.[2]

History

Historians and scientists speculate that feral horses have lived on and near Pryor Mountains since at least the late 1600s.[7] Crow Indian tradition maintains that the horses were brought to the area by about 1725. Non-Indian explorers found native people in possession of large numbers of horses as early as 1743.[8] Thousands of feral horses lived in the area by the time American pioneers began settling near the Pryor Mountains in the late 1800s.[9]

It was widely believed that the Pryor Mountains horses were direct descendants of the Barb horses brought to North America by Juan de Oñate's expedition to explore America north of the Rio Grande in the early 1600s.[9] Their bloodlines may also include American Saddlebred, Canadian, Irish Hobby, and Tennessee Walking horses.[9] But this was in dispute for many years. Some people claimed that the horses were nothing more than local domestic horses which had escaped to the wild. In 1992, equine geneticist Dr. E. Gus Cothran ran genetic studies on the herd, and concluded that their primary bloodline descends from Spanish Barbs.[8][6] Since no genetic variants were observed which were not also seen in domestic horse breeds, in 2010 Cothran concluded the horses were not a unique species which had survived from prehistoric times.[10] Rather, they were linear descendants of the Spanish Barb, with some evidence of genetic similarity to light racing and riding breeds.[11] The genetic tests also revealed that the Pryor Mountains horses carried a rare allele variant known as "Qac" that only Spanish horses brought to the Americas also carried.[12] Dr. D. Phillip Sponenberg of the Virginia–Maryland Regional College of Veterinary Medicine, and an expert on horse breeds, observed that, physically, the horses conform to the Colonial Spanish Horse type.[6] Genetic studies have also revealed that the herd exhibits a high degree of genetic diversity,[8] and BLM has acknowledged the genetic uniqueness of the herd.[6]

Management

BLM counts the herd visually about every four years by flying over the range, reporting on each animal found, and using statistical methods to correct for historic undercounting and other problems.[13] In 1984, BLM set the maximum carrying capacity of the Pryor Mountains Wild Horse Range at 121 adult animals, and revised this to 95 adult animals in 1992.[14]

Management of the Pryor Mountains horse herd has focused on fulfilling the Free-Roaming Wild Horse and Burro Act's requirement that BLM maintain a "thriving natural ecological balance". In general, BLM initially focused on how many horses the range could support and in maintaining conformity to the Pryor Mountains standard. However, with the development of DNA testing in the mid 1980s, the focus changed to maintaining the herd's genetic viability as well. In 1988, researchers at Washington State University authored a paper which raised concern that the herd exhibited a lack of genetic diversity, and could be suffering from genetic drift and/or a population bottleneck.[15] BLM contracted with veterinarian E. Gus Cothran (then at the College of Veterinary Medicine at the University of Kentucky, but now at the Texas A&M College of Veterinary Medicine & Biomedical Sciences) to take random genetic samples of the herd in 1994, 1997, and 2001.[11] Cothran's analysis found "no evidence of a bottleneck".[16] Genetic diversity was actually above the mean for feral horse herds in the United States, and just below the mean for domesticated breeds.[10] The BLM, however, interpreted these studies in 2009 to indicate that the genetic diversity of the Pryor Mountains herd is "well above" the mean for domestic breeds.[17] Cothran considered the herd to be in genetic equilibrium,[11] although he cautioned that a minimum of 120 breeding-age animals should be kept on the range to maintain the genetic health of the herd.[16] Research by biologists and veterinarians at Colorado State University, the University of Kentucky, and other colleges found that there is little inbreeding in bands, as the stallions tend to drive off colts when they are about two years old.[2][17]

For years, BLM had also allowed any horse to be adopted from the range. Since adopters favored "pretty" horses, the color genetics of the herd altered so that mostly bays and blacks were left on the range.[18] Adoption procedures changed in 1994 so that now the original colors and patterns of the herd are returning.[18] That same year, a private group calling itself the Pryor Mountains Mustang Breeders Association was formed to preserve the gene pool of the herd and establish a registry for Pryor Mountains horses in private hands.[18] In order to be placed on the register, the horse must have a registered sire and dam, have a title issued either by BLM or the Tillett ranch, and have a certificate of blood typing from the Gluck Equine Research Center at the University of Kentucky.[18] As of 2008, 209 horses in 16 U.S. states and one Canadian province were on the registry.[5]

BLM undertook a roundup of the horse herd in 1997 to reduce its numbers, and The BLM officials expected to do another in late 2000 when the herd size reached 200.[2] By August 1999, there were 180 adult horses and colts on the range.[2] In May 2009, after several long-term studies of the rangeland, The BLM determined that the range's maximum carrying capacity was 179 feral horses.[19] This assumed that all BLM land, as well as lands leased from other owners (public and private), would continue to be available to the animals, and that BLM would be able to manage the horses by using artificial watering sites to encourage the horses to utilize undergrazed portions of the range.[19] The BLM also said it would implement other range management techniques[20] The BLM also proposed purchasing 1,467 acres (594 ha) of land from the state of Montana, and another 632 acres (256 ha) of private land, to add to the range.[19]

At the same time, BLM said it would reduce the herd from its existing 195 adults to 120.[21] The stated goal was to temporarily remove horses from the refuge to allow the range to recover from the historic overgrazing caused by livestock, not because BLM believed there were too many horses on the range.[22] Sixty percent of the remaining horses would be males, to reduce the rate of population growth.[21] The agency said it would remove 30 horses a year from the herd and stable them at a yearly cost of $18,000 to $21,000 until the correct herd size and sex ratios had been reached.[21] Horses to be removed from the herd included those which did not closely fit the conformity type; which were genetically well-represented; which were 11 to 15 years of age, had sired or foaled, and were not band stallions; and were between five and 10 years of age or 16 to 20 years of age.[23] Genetic diversity would be measured by visual observation of the herd's conformity to type using a visual system developed by Dr. Sponenberg,[24] and measures taken to improve genetic diversity if signs of inbreeding occurred.[17] The Cloud Foundation and Front Range Equine Rescue, both feral horse advocacy groups, challenged the roundup in federal court.[25] A federal district court judge delayed the roundup three days to consider their request, but on September 2, 2009, rejected the injunction and allowed the roundup to proceed.[25][26] BLM began its roundup of feral horses on the Pryor Mountains range in early September 2009. After several days, 130 of 188 feral horses were rounded up.[26] Forty-six horses were put up for adoption,[26] while the freed mares were given a contraceptive vaccine to help keep the herd population down.[25]

At this time, BLM also placed "guzzlers" on the range. A guzzler is a precipitation (usually rainwater) collection device which traps water in a storage tank ranging in size from a few to several thousand gallons. The storage tank can be above-ground, partially buried, or below-ground. A mechanical valve releases water into a drinking trough from the storage tanks, allowing animals access to the water. When the valve senses that the water level in the trough is low, it opens and allows more water into the drinking area.[27] Five guzzlers were placed in undergrazed areas to encourage the horses to better utilize this forage.[21]

In the fall of 2010, BLM issued a set of draft strategy documents for operating its wild horse programs, and solicited public comment on the plans.[28] After receiving numerous comments, BLM said in February 2011 it would quicken the pace at which it made revisions to its roundup procedures, use of fertility control drugs, and wild horse and burro range land management.[28] The agency also commissioned a study from the National Academies of Science (NAS) on wild-horse management. Due for release in 2013, independent NAS experts will study a wide variety of issues, including the carrying capacity of wild horse and burro ranges, wild horse and burro population growth, and best practices in fertility control.[28]

In September 2011, BLM announced it would begin working with the Humane Society of the United States to develop new practices in herd management and roundup, and increase its emphasis on adoptions and the use of drugs as fertility control to help better manage its wild horse herds.[28]

Tourism

Main article: Pryor Mountains Wild Horse Range

The Pryor Mountains feral horse herd is one of the most accessible feral horse herds in the United States.[6] Tourism to the range increased steadily in the mid to late 2000s.[29] The range can be easily accessed via a paved road which parallels Bighorn Canyon, and which provides excellent viewing of the horses.[30] The range can also be accessed from Laurel, Montana, by traveling south on U.S. Route 310 and then taking the Forest Service gravel road to Dryhead Overlook.[31] Some of the range may be accessed via the Crow Indian Reservation. A trespass permit from the Crow Nation is required to cross tribal land or exit a vehicle while on tribal land.[32] Hiking on the Pryor Mountains Wild Horse range is good, but there are no maintained or marked trails and (as of 2000) no guidebooks to the area.[33]

References

  1. ^ Quoted in Ryden, p. 320.
  2. ^ a b c d e f g h i j k l Cohen, Betsy. "Survivors of Time: Lost Horses of the Pryor Mountains." The Missoulian. August 15, 1999. Accessed 2011-06-07.
  3. ^ Hill, p. 361.
  4. ^ a b Dutson, p. 209
  5. ^ a b c d e f g h i j k l m n o p q r Lynghaug, p. 106.
  6. ^ a b c d e f Lynghaug, p. 104.
  7. ^ Singer and Schoenecker, p. 39.
  8. ^ a b c Massingham, p. 15.
  9. ^ a b c Cruise, p. 185
  10. ^ a b Cothran, p. 3. Accessed 2011-06-07.
  11. ^ a b c Cothran, p. 4. Accessed 2011-06-07.
  12. ^ Billings Field Office, p. 8. Accessed 2011-06-07.
  13. ^ Government Accountability Office, p. 2. Accessed 2011-06-07.
  14. ^ Government Accountability Office, p. 71. Accessed 2011-06-07.
  15. ^ See, generally: Kirkpatrick and Gilluly, 1988. Accessed 2011-06-07.
  16. ^ a b Cothran, p. 5. Accessed 2011-06-07.
  17. ^ a b c Billings Field Office, p. 18. Accessed 2011-06-07.
  18. ^ a b c d Lynghaug, p. 105.
  19. ^ a b c Billings Field Office, p. 11. Accessed 2011-06-07.
  20. ^ See: Billings Field Office, p. 104. Accessed 2011-06-07.
  21. ^ a b c d French, Brett. "Wild Horse Range Pressured By Overgrazing." Billings Gazette. July 12, 2009. Accessed 2011-06-07.
  22. ^ Billings Field Office, p. 103. Accessed 2011-06-07.
  23. ^ Billings Field Office, p. 27. Accessed 2011-06-07.
  24. ^ Billings Field Office, p. 20. Accessed 2011-06-07.
  25. ^ a b c "Wild Horse Roundup in Pryor Mountains to Begin." Associated Press. September 3, 2009.
  26. ^ a b c French, Brett. "Wild Horse Roundup Nears End." Billings Gazette. September 9, 2009. Accessed 2011-06-07.
  27. ^ For general information on guzzlers, see: Mitchell, Dean; Larsen, Randy; and Raymer, Danny. "What the Heck Is A Guzzler?" Wildlife Review. August 2006. Accessed 2011-06-08.
  28. ^ a b c d Whitcomb, Rachel. "BLM Eyes Greater Cooperation With HSUS on Wild-Horse Gather." DVM Newsmagazine. September 1, 2011. Accessed 2011-09-26.
  29. ^ Billings Field Office, p. 67. Accessed 2011-06-07.
  30. ^ "Pryor Mountains Wild Horse Range." Montana Office of Tourism. No date. Accessed 2011-06-07.
  31. ^ Rowles, p. 98.
  32. ^ Fischer and Fischer, p. 74.
  33. ^ Kesselheim, Alan. "Running With the Herd." Backpacker. May 2000, p. 93.

Sources