---
title: "What the sources say about the Bighorn Sheep | AnimalTracks.wiki"
description: "44 claims from the Bighorn Sheep profile, each beside the words of the source that backs it."
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# What the sources say about the Bighorn Sheep (*Ovis canadensis*)

> 44 claims from the Bighorn Sheep profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Bighorn Sheep](https://animaltracks.wiki/animals/bighorn-sheep/)

## Bighorn Sheep. National Wildlife Federation, Wildlife Guide.

https://www.nwf.org/Educational-Resources/Wildlife-Guide/Mammals/Bighorn-Sheep

| The page says | The source says |
| :--- | :--- |
| Horns weighing up to thirty pounds | Large, curved horns—borne by the males, or rams—can weigh up to 30 pounds (14 kilograms), as much as the rest of the bones in the male's body. |
| hooves shaped to snag any slight protrusion | The outer hooves are modified toenails shaped to snag any slight protrusion, while a soft inner pad provides a grip that conforms to each variable surface. |
| Grasses, clover and sedges in warmer months, switching to woody plants like willow and sage in colder months; desert sheep often eat holly and cactus | In warmer months, bighorn sheep browses on grasses, clover, and sedges. It transitions to eating woody plants like willow and sage in colder months. In desert areas, bighorn sheep often eat plants such as holly and cacti. |
| The bighorn sheep (Ovis canadensis) has a compact, muscular body, and it is one of two wild sheep species in North America with large horns | The bighorn sheep's compact body is muscular ... The bighorn sheep is one of two species of wild sheep in North America with large horns |
| Most weigh 73 to 113 kilograms (160 to 250 pounds), but males may weigh more than 159 kilograms (350 pounds) and stand around 102 centimeters (40 inches) at the shoulder | Most weigh 160 to 250 pounds (73 to 113 kilograms), but males may weigh more than 350 pounds (159 kilograms) and stand around 40 inches (102 centimeters) at the shoulder. |
| A ram's curved horns can weigh up to 14 kilograms (30 pounds), as much as the rest of the bones in his body | Large, curved horns—borne by the males, or rams—can weigh up to 30 pounds (14 kilograms), as much as the rest of the bones in the male's body. |
| Horns that can weigh as much as the rest of his skeleton | Large, curved horns—borne by the males, or rams—can weigh up to 30 pounds (14 kilograms), as much as the rest of the bones in the male's body. |
| An older ram's horns can grow over 0.9 meters (three feet) long | Older rams have massive horns that can grow over three feet (0.9 meters) long |
| In warmer months they eat grasses, clover and sedges, switching to woody plants like willow and sage in colder months, and desert sheep often eat holly and cactus | In warmer months, bighorn sheep browses on grasses, clover, and sedges. It transitions to eating woody plants like willow and sage in colder months. In desert areas, bighorn sheep often eat plants such as holly and cacti. |
| A complex four-part stomach lets them eat large portions fast, then retreat to cliffs or ledges to rechew their food, safe from predators | As ruminants, grass-eating bighorn sheep have a complex four-part stomach that enables them to eat large portions rapidly before retreating to cliffs or ledges where they can thoroughly rechew and digest their food, safe from predators. |
| Though not as agile as mountain goats, bighorns are well equipped for climbing the steep terrain that keeps their predators at bay | Although not as agile as mountain goats, bighorn sheep are well-equipped for climbing the steep terrain that keeps their predators at bay. |
| The outer hoof is a modified toenail shaped to snag any slight protrusion, while a soft inner pad grips and conforms to each surface | The outer hooves are modified toenails shaped to snag any slight protrusion, while a soft inner pad provides a grip that conforms to each variable surface. |
| Their mountain habitat has ledges sometimes only five centimeters (two inches) wide, and it gives cover from predators such as coyotes, golden eagles, mountain lions, bears and Canada lynx | Their steep mountainous habitat, with ledges sometimes only two inches (five centimeters) wide, provides cover from predators such as coyotes, golden eagles, mountain lions, bears, and Canada lynx |
| Ewes grow horns too, but theirs stay short with only a slight curve | Females, or ewes, also have horns, but they are short with only a slight curvature. |
| Their steep habitat has ledges sometimes only five centimeters (two inches) wide | Their steep mountainous habitat, with ledges sometimes only two inches (five centimeters) wide |
| The species has three living subspecies: the Rocky Mountain, Sierra Nevada and desert bighorns. | "bighorn sheep" is one species, with three living subspecies: the Rocky Mountain bighorn sheep (Ovis canadensis canadensis), the Sierra Nevada bighorn sheep (Ovis canadensis sierrae)—formerly called the California bighorn sheep, and the desert bighorn sheep (Ovis canadensis nelsoni). |

## Bighorn Sheep. Rocky Mountain National Park, National Park Service.

https://www.nps.gov/romo/learn/nature/bighorn_sheep.htm

| The page says | The source says |
| :--- | :--- |
| head-first charges at up to forty mph | rams face each other, rear up on hind legs and pitch forward at speeds up to 40 mph |
| the thick, bony skull absorbs repeated head-on clashes at up to 40 mph with little injury to the ram | rams face each other, rear up on hind legs and pitch forward at speeds up to 40 mph ... Bighorn sheep skulls are thick and bony to absorb this repeated impact with little physical injury to the ram. |
| A bighorn's lifespan is about 10 years | The lifespan of bighorn sheep is approximately 10 years. |
| Mating season comes in the fall, when rams fight for dominance or mating rights | Mating occurs in the fall when rams use their horns as weapons of battle to fight for dominance or female mating rights. |
| They rear up on their hind legs and pitch forward at each other at up to 64 kilometers per hour (40 mph), and the crash of horns can be heard up to a mile away | rams face each other, rear up on hind legs and pitch forward at speeds up to 40 mph. The loud crash of horns signals contact and can be heard up to one mile away. (note: 40 mph converted to 64 km/h (40 mph = 64.4 km/h); the quote itself only states 40 mph.) |
| The ritual repeats until one ram concedes and walks away | This ritual is repeated until one animal concedes and walks away. |
| The skull is built for it: thick and bony, it absorbs the repeated impact with little injury to the ram | Bighorn sheep skulls are thick and bony to absorb this repeated impact with little physical injury to the ram. |
| Rival rams rear up on their hind legs and pitch forward at speeds up to 64 kilometers per hour (40 miles per hour). The loud crash of horns can be heard up to a mile away. | rams face each other, rear up on hind legs and pitch forward at speeds up to 40 mph. The loud crash of horns signals contact and can be heard up to one mile away. (note: 40 mph converted to 64 km/h (40 mph = 64.4 km/h); the quote itself only states 40 mph.) |
| rear up and pitch forward at each other at up to 64 kilometers per hour | rams face each other, rear up on hind legs and pitch forward at speeds up to 40 mph. The loud crash of horns signals contact and can be heard up to one mile away. (note: vibe.reason (#692 re-home); 40 mph converted to 64 km/h) |
| The ritual repeats until one ram concedes and walks away | This ritual is repeated until one animal concedes and walks away. (note: vibe.reason (#692 re-home)) |

## Ovis canadensis (bighorn sheep). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Ovis_canadensis/

| The page says | The source says |
| :--- | :--- |
| Alpine meadows, grassy mountain slopes and foothills near rugged, rocky cliffs in the Rocky Mountains | Ovis canadensis canadensis inhabits alpine meadows, grassy mountain slopes and foothill country in proximity to rugged, rocky cliffs and bluffs. (note: ADW's habitat line is for the Rocky Mountain subspecies O. c. canadensis; the range quote places the species in the Rocky Mountains.) |
| plus a desert subspecies from Nevada and California to west Texas and Mexico | Ovis canadensis is found in the Rocky Mountains from southern Canada to Colorado, and as a desert subspecies (O. c. nelsoni) from Nevada and California to west Texas and south into Mexico. |
| A double-layered skull shored with struts of bone and a massive tendon linking skull to spine | Bighorn sheep have double-layered skulls shored with struts of bone for battle protection. They also have a broad, massive tendon linking skull and spine to help the head pivot and recoil from blows. |
| It is double-layered and shored with struts of bone, while a broad, massive tendon linking skull to spine helps the head pivot and recoil from blows | Bighorn sheep have double-layered skulls shored with struts of bone for battle protection. They also have a broad, massive tendon linking skull and spine to help the head pivot and recoil from blows. |
| Bighorns live in the Rocky Mountains from southern Canada to Colorado, and a desert subspecies ranges from Nevada and California to west Texas and south into Mexico | Ovis canadensis is found in the Rocky Mountains from southern Canada to Colorado, and as a desert subspecies (O. c. nelsoni) from Nevada and California to west Texas and south into Mexico. |
| dangerLevel: Low | There are no known negative effects of bighorn sheep on humans. |

## Ovis canadensis. AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources.

https://genomics.senescence.info/species/entry.php?species=Ovis_canadensis

| The page says | The source says |
| :--- | :--- |
| the record in captivity is 20.6 years | Record longevity in captivity is 20.6 years |

## Festa-Bianchet (2020). Ovis canadensis. The IUCN Red List of Threatened Species 2020: e.T15735A22146699.

https://doi.org/10.2305/iucn.uk.2020-2.rlts.t15735a22146699.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | IUCN Red List category: Least Concern (LC). (note: read through GBIF's copy of the Red List per docs/fact-check.md; the assessment text itself (doi: 10.2305/iucn.uk.2020-2.rlts.t15735a22146699.en) is a hand check beyond the category.) |

## Coltman et al. (2003). Undesirable evolutionary consequences of trophy hunting. Nature.

https://doi.org/10.1038/nature02177

| The page says | The source says |
| :--- | :--- |
| In one wild population, sport hunting drove evolution: rams' body weight and horn size declined significantly over time | Here we show that in an evolutionary response to sport hunting of bighorn trophy rams (Ovis canadensis) body weight and horn size have declined significantly over time. ... based on a partly genetically reconstructed pedigree from a 30-year study of a wild population in which trophy hunting targeted rams with rapidly growing horns |
| A 30-year study of that population, where trophy hunting targeted rams with rapidly growing horns, found both traits were highly heritable | based on a partly genetically reconstructed pedigree from a 30-year study of a wild population in which trophy hunting targeted rams with rapidly growing horns ... Both traits were highly heritable |
| The rams hunters shot had higher genetic value for weight and horn size than the rams they spared, and they were shot at an early age, so they did not achieve high breeding success | trophy-harvested rams were of significantly higher genetic 'breeding value' for weight and horn size than rams that were not harvested. Rams of high breeding value were also shot at an early age, and thus did not achieve high reproductive success. |
| Under unrestricted trophy hunting, the population's genetic averages for both traits fell, leaving smaller-horned, lighter rams and fewer trophies | Declines in mean breeding values for weight and horn size therefore occurred in response to unrestricted trophy hunting, resulting in the production of smaller-horned, lighter rams, and fewer trophies. |
| Yes, in at least one long-studied wild population | based on a partly genetically reconstructed pedigree from a 30-year study of a wild population in which trophy hunting targeted rams with rapidly growing horns |
| A 30-year study found that horn size and body weight were both highly heritable there | based on a partly genetically reconstructed pedigree from a 30-year study of a wild population in which trophy hunting targeted rams with rapidly growing horns ... Both traits were highly heritable |
| rams of high genetic value for both traits were shot at an early age, so they did not achieve high breeding success | trophy-harvested rams were of significantly higher genetic 'breeding value' for weight and horn size than rams that were not harvested. Rams of high breeding value were also shot at an early age, and thus did not achieve high reproductive success. |
| Under unrestricted trophy hunting, the population's genetic averages for weight and horn size declined, leaving smaller-horned, lighter rams | Declines in mean breeding values for weight and horn size therefore occurred in response to unrestricted trophy hunting, resulting in the production of smaller-horned, lighter rams, and fewer trophies. |

## Jones et al. (2022). Desert bighorn sheep habitat selection, group size, and mountain lion predation risk. The Journal of Wildlife Management.

https://doi.org/10.1002/jwmg.22173

| The page says | The source says |
| :--- | :--- |
| A 2013 to 2017 GPS-collar study of two Arizona desert populations found that sheep using more rugged areas and steeper slopes were less likely to be killed by a mountain lion | We fit 103 bighorn sheep (81 females and 22 males) with global positioning system radio‐collars in 2 Arizona populations from 2013 to 2017 ... The use of more rugged areas and steeper slopes decreased the risk of mortality due to mountain lion predation, consistent with presumed predator avoidance strategies. (note: 'desert' is from the paper's title, 'Desert bighorn sheep habitat selection, group size, and mountain lion predation risk'.) |
| Bigger groups also cut the risk, though the benefit became marginal at about ten sheep a group | Increased group size decreased risk of bighorn sheep mortality due to mountain lion predation but this effect became marginal at approximately 10 individuals/group. |