Animal Diversity Web

Ge­o­graphic Range

Due to the do­mes­ti­ca­tion of Equus ca­bal­lus, and its wide­spread dis­tri­b­u­tion fol­low­ing do­mes­ti­ca­tion, the nat­ural ge­o­graphic range is typ­i­cally con­sid­ered the dis­tri­b­u­tion in the Late Glacial pe­riod, 9,500-15,000 years ago. Dur­ing this time, horses were wide­spread. Wild horse pop­u­la­tions ex­isted in the north­ern tip of Africa ad­ja­cent to the Tyrrhen­ian and Mediter­ranean Seas, across Eu­rope ex­clud­ing the most north­ern re­gions where the Scan­di­na­vian coun­tries cur­rently exist, and as far east in the Palearc­tic re­gion as China and Mon­go­lia. They ex­tended through­out the north­ern Palearc­tic, across Beringia into the Yukon, and as far south in North Amer­ica as Mex­ico, as far east as the Mis­sis­sippi River, and as far west as the Pa­cific Ocean coast­line. It is be­lieved that the wild horses in North Amer­ica went ex­tinct 8,000 to 10,000 years ago. Do­mes­tic horses were then in­tro­duced into North Amer­ica upon Eu­ro­pean col­o­niza­tion. (Ben­nett and Hoff­mann, 1999)

• Biogeographic Regions
• nearctic
  • introduced
  • native
• palearctic
  • native
• oriental
  • native
• ethiopian
  • introduced
• neotropical
  • introduced
• australian
  • introduced
• oceanic islands
  • introduced

• Other Geographic Terms
• holarctic
• cosmopolitan

Habi­tat

Horses are adapt­able and oc­cupy a wide va­ri­ety of habi­tats under do­mes­ti­ca­tion. Pre­ferred habi­tats are cool, tem­per­ate grass­lands, steppes, and sa­van­nahs, but they also oc­cupy semi-deserts, swamps, marshes, and wood­lands. (Ben­nett and Hoff­mann, 1999)

• Habitat Regions
• temperate
• polar
• terrestrial

• Terrestrial Biomes
• tundra
• savanna or grassland
• forest

• Wetlands
• marsh
• swamp

• Other Habitat Features
• agricultural
• riparian

Phys­i­cal De­scrip­tion

Horses are un­gu­lates with an un­guligrade foot pos­ture, sin­gle-digit oval-shaped hooves, long tails, short hair, long slen­der legs, mus­cu­lar and deep torso build, long thick necks, and large elon­gated heads. The mane is a re­gion of coarse hairs, which ex­tends along the dor­sal side of the neck in both do­mes­tic and wild species. How­ever, wild horses have a mane with short hairs that re­main up­right while do­mes­tic horses have longer mane hairs that do not re­main up­right. A mid-dor­sal stripe, a dark stripe that ex­tends from the mane to the tail, is some­times pre­sent, es­pe­cially in wild types. The teeth are spe­cial­ized for graz­ing, with hyp­sodont cheek­teeth. The den­tal for­mula is 3/3, 0-1/0-1, 3-4/3-4, and 3/3. New­born horses have curly hairs and a finer mane than adults be­fore molt­ing and grow­ing their win­ter coat. Win­ter coats start de­vel­op­ing in Sep­tem­ber and Oc­to­ber, are fully grown by De­cem­ber. They start shed­ding in the sum­mer over a pe­riod of 56 days for adults or 75 days for new­borns. Win­ter coats are typ­i­cally thicker and the top of the tail usu­ally de­vel­ops a re­gion of short hairs, form­ing a tuft. (Ben­nett and Hoff­mann, 1999; Hansen, 1976)

Do­mes­ti­ca­tion of horses has led to wide vari­a­tion in the char­ac­ter­is­tics of breeds of horses. Coats vary in color, from white to black and in­clud­ing reds, browns, and yel­lows, as well as a wide va­ri­ety of pat­terns, such as spots and pinto pat­terns. Size can vary de­pend­ing on the breed and its in­tended use, but can range from 227 to 900 kg in mass and 0.9 to 1.7 me­ters in height, with po­ten­tial out­liers. Leg length, head length, body-build, fur color, me­tab­o­lism, etc, varies across breeds of do­mes­tic horses. De­spite the great vari­a­tion in phys­i­cal fea­tures within horses, they can gen­er­ally be dis­tin­guished from other equids, by hav­ing longer manes and tails and gen­er­ally a lack of ze­bra-type stripes. (Ben­nett and Hoff­mann, 1999; En­s­minger, 1969)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Range mass

  227 to 900 kg

  500.00 to 1982.38 lb

• Range length

  220 to 280 cm

  86.61 to 110.24 in

• Average basal metabolic rate

  0.11 cm3.O2/g/hr

Re­pro­duc­tion

The horse mat­ing sys­tem is sim­i­lar to that of other equids, which is a polyg­y­nous mat­ing sys­tem. Males typ­i­cally herd fe­males dur­ing the mat­ing sea­son and de­fend them against other males, who may be try­ing to mate with the fe­males. Males do not typ­i­cally herd and mate with any of his daugh­ters or any fe­males that grew up with him in the same herd. Males fight with other males through kick­ing and bit­ing, losers sub­mit and re­treat. This process is very en­ergy in­ten­sive and sim­i­lar to the rut seen in deer species. Hi­er­ar­chy in herds is in­flu­ences by re­pro­duc­tive sta­tus and age, with fe­males and their new­born young get­ting first ac­cess to re­sources, fol­lowed by ju­ve­niles and non-re­pro­duc­tive fe­males. Alpha males dom­i­nate ac­cess to re­sources. (Ben­nett and Hoff­mann, 1999; Lin­klater, et al., 1999)

• Mating System
• polygynous

Males can re­pro­duce year-round but are most ac­tive from April to June. Fe­males are polye­strous dur­ing the breed­ing sea­son and go into an es­trous pe­riod on av­er­age every 21 days, each last­ing an av­er­age of 6.5 days. Fe­males have spon­ta­neous ovu­la­tion one to two days be­fore the es­trous pe­riod is over, which is when they are most fer­tile. In au­tumn, fe­males no longer go through es­trous pe­ri­ods until near­ing the next breed­ing sea­son. Av­er­age ges­ta­tion pe­riod is 335 days, but ranges from 287 to 419 days. This broad ges­ta­tion range means that birth can be in ei­ther spring or au­tumn of the next year. If the foal is not born by the time in which the mare would go into es­trous dur­ing the breed­ing sea­son, then she can­not par­tic­i­pate that year. Usu­ally only one foal is pro­duced an­nu­ally, and it is rare to see twin foals. In do­mes­tic horses, only 14% of twin foals sur­vive two weeks, and ei­ther one or both twins are born un­der­de­vel­oped. (Ben­nett and Hoff­mann, 1999; En­s­minger, 1969)

Births occur at night and in a quiet lo­ca­tion. Wild horse foals are usu­ally born at a mass of 25 to 30 kg, but the av­er­age birth weight of do­mes­ti­cated foals is 40 kg. Foals are born pre­co­cial and well-de­vel­oped, usu­ally being able to stand within an hour of birth and walk within four to five hours to fol­low their mother. When the mother re­turns to the herd, she goes through post­par­tum es­trus for usu­ally seven to nine days, which is sig­nif­i­cantly less than reg­u­lar es­trus pe­ri­ods. In do­mes­ti­cated horses who do not have a herd, post­par­tum es­trus usu­ally hap­pens five to twelve days after giv­ing birth. Foals are able to eat solid food within a week of being born. For their first month, the young stay close to their mother and nurse for brief and fre­quent pe­ri­ods be­fore their sec­ond month, when they start to for­age on their own. When they start to for­age in­de­pen­dently, they begin the wean­ing process which could take up to two years for wild foals. In do­mes­ti­cated horses, foals are often weaned be­tween four and six months old. (Ben­nett and Hoff­mann, 1999; En­s­minger, 1969)

Foal weight dou­bles every week for four weeks, then grad­u­ally de­clines as they reach ma­tu­rity. It takes fe­males four to five years, and males six to seven years, to reach full re­pro­duc­tive ma­tu­rity. Al­though fe­males first go into es­trus at ei­ther 11 or 12 months, they are not usu­ally fer­tile until their sec­ond year. Even then, fe­males have dif­fi­culty de­vel­op­ing the fetus of a foal and giv­ing birth, with­out se­vere health com­pli­ca­tions to her­self or the foal, until they are four years of age. (Ben­nett and Hoff­mann, 1999; En­s­minger, 1969)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• viviparous
• post-partum estrous

• Breeding interval

  Horses may breed up to once each year.

• Breeding season

  Horses generally breed from April to June.

• Range number of offspring

  1 to 2

• Average number of offspring

  1

  AnAge

• Range gestation period

  287 to 419 days

• Average gestation period

  335 days

• Range weaning age

  24 (high) months

• Range time to independence

  2 to 3 years

• Range age at sexual or reproductive maturity (female)

  11 to 48 months

• Average age at sexual or reproductive maturity (female)

  36 months

• Average age at sexual or reproductive maturity (male)

  6 years

• Average age at sexual or reproductive maturity (male)
  Sex: male

  973 days

  AnAge

Foals are pre­co­cial at birth and able to walk on their own shortly after birth, but still need parental as­sis­tance. Al­though they are pre­co­cial, they rely heav­ily on their mother for pro­tec­tion against preda­tors and food until they begin to for­age on their own. Being re­cently born, foals get ac­cess to food re­sources sec­ond to the alpha male of the herd. As they ma­ture into ju­ve­niles, they even­tu­ally get ac­cess to food after re­cently born foals, but still be­fore sin­gle and non-re­pro­duc­tive fe­males. Al­though young pri­mar­ily learn by ob­ser­va­tion of their mother in the first cou­ple months, the herd also pro­vides a learn­ing en­vi­ron­ment and pro­tec­tion against preda­tors. Some­times, fe­males will nip their young for dis­ci­pline as well. Herd hi­er­ar­chy is also taught through kick­ing, bit­ing, vo­cal­iza­tion, and fa­cial ges­tures be­tween in­di­vid­u­als for com­mu­ni­ca­tion. Al­though young are pre­co­cial and grow rel­a­tively quickly, they do rely on the pro­tec­tion, group care, and learn­ing ex­pe­ri­ences of­fered by the herd on their mother for de­vel­op­ment in wild horses. Stud­ies show that feral horses are no longer de­pen­dent on their natal herd and tend to dis­perse to other herds in their 2nd or 3rd year of age. Gen­der is not a fac­tor in the age at which hoses dis­perse from their natal herd. Do­mes­ti­cated foals are usu­ally sep­a­rated from their mother ei­ther dur­ing or im­me­di­ately after the wean­ing process is com­plete. (Ben­nett and Hoff­mann, 1999; Cameron, et al., 2003; En­s­minger, 1969)

• Parental Investment
• precocial
• female parental care
• pre-fertilization
  • provisioning
  • protecting
    • male
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female
• maternal position in the dominance hierarchy affects status of young

Lifes­pan/Longevity

Horse lifes­pan is de­pen­dent on sev­eral fac­tors, in­clud­ing breed vari­a­tions and en­vi­ron­ment. Typ­i­cally, do­mes­tic horses have a lifes­pan of 25 to 30 years, al­though a max­i­mum of 61 years has been at­tained. The longest liv­ing horse in wild as of 1974 was 36 years. Fac­tors on lifes­pan of E. ca­bal­lus in­clude: nu­tri­tion, ac­tiv­ity, num­ber of re­pro­duc­tion cy­cles, re­pro­duc­tive sta­tus, dis­ease, den­tal health, and phys­i­cal ac­tiv­ity. (Ben­nett and Hoff­mann, 1999; En­s­minger, 1969)

• Range lifespan
  Status: wild

  36 (high) years

• Range lifespan
  Status: captivity

  61 (high) years

• Average lifespan
  Status: captivity

  25-30 years

• Average lifespan
  Status: captivity

  50.0 years

  Max Planck Institute for Demographic Research

• Average lifespan
  Status: wild

  62.0 years

  Max Planck Institute for Demographic Research

Be­hav­ior

Horses are so­cial mam­mals. In wild or feral pop­u­la­tions they form herds with a so­cial hi­er­ar­chy. These herds, also known as bands, can have up to 26 mares, 5 stal­lions, and var­i­ous ages of pre-dis­persed young. Typ­i­cal herd sizes will have only 5 to 11 mares and 1 to 4 stal­lions, in ad­di­tion to their off­spring, but these num­bers vary among schol­arly ar­ti­cles and may vary with food avail­abil­ity, en­vi­ron­men­tal con­di­tions, and other fac­tors. This hi­er­ar­chy is com­prised of the alpha male being dom­i­nant over the herd, males dom­i­nant over fe­males, fe­males with young dom­i­nant over non-re­pro­duc­tive fe­males, and adults being dom­i­nant over ju­ve­niles. The dom­i­nant or alpha male is sig­nif­i­cantly more ac­tive than other mem­bers of the herd. Stud­ies show that, in feral horses, where reg­u­lar mem­bers of the herd usu­ally spend less than 10% of their time mov­ing around, dom­i­nant males move from 25 to 45% of the time and sleep only 5 to 6% of their time, when the other herd mem­bers usu­ally spend 20 to 27% of the time through­out the day sleep­ing. Alpha males also ex­pend large amounts of en­ergy round­ing up fe­males and de­fend­ing them against other males dur­ing the breed­ing sea­son. Alpha males usu­ally move in the back of the herd, but will move to the front in the pres­ence of a threat and sig­nal to the herd in the event that the herd needs to flee. The alpha may also at­tack a threat if nec­es­sary to de­fend the herd. (Ben­nett and Hoff­mann, 1999; En­s­minger, 1969; Lin­klater, et al., 1999)

Horses are cre­pus­cu­lar and have an in­ter­rupted sleep­ing pat­tern that com­pli­ments this. Dur­ing the sum­mer, horses graze in morn­ing or evenings to avoid mid-day high tem­per­a­tures, and can be seen vis­it­ing water sources at night as well. To adapt to this feed­ing pat­tern, they sleep in seg­ments through­out the day, which are usu­ally not more than two hours long. They also avoid lay­ing down for more than an hour at a time if pos­si­ble, and can be seen sleep­ing while stand­ing up. (Ben­nett and Hoff­mann, 1999)

• Key Behaviors
• cursorial
• terricolous
• crepuscular
• motile
• nomadic
• social
• dominance hierarchies

• Range territory size

  0.59 to 17.68 km^2

Home Range

Wild horses gen­er­ally stay close to water sources but, in tran­si­tion be­tween spring and sum­mer when food is most abun­dant, horses can travel far from their water ac­cess points. One study in a feral pop­u­la­tion in New Zealand showed that home range sizes were be­tween 0.96 to 17.68 square kilo­me­ters, with a den­sity of 0.48 to 3.22 in­di­vid­u­als per square kilo­me­ter. Herd size and home range are pos­i­tively cor­re­lated, with a larger herd oc­cu­py­ing a larger home range. Some stud­ies on wild or feral horses show that there are sea­sonal move­ments and vari­a­tion in the home range. These sea­sonal move­ments are typ­i­cally as­so­ci­ated with reg­u­lar sea­sonal pre­cip­i­ta­tion changes, food avail­abil­ity, tem­per­a­tures, and topog­ra­phy. In win­ter, pop­u­la­tions move away from lower el­e­va­tions that were ex­posed to un­usu­ally cooler tem­per­a­tures due to frost in­ver­sion lay­ers, but would re­turn prior to foal­ing or the mat­ing sea­son. Win­ter home ranges in feral pop­u­la­tions are larger than sum­mer home ranges on av­er­age, but these ranges vary sig­nif­i­cantly. True wild horse pop­u­la­tion are re­stricted to var­i­ous re­serves and rein­tro­duc­tion sites for their pro­tec­tion. (Ben­nett and Hoff­mann, 1999; Boyd and King, 2014; Lin­klater, et al., 1999; Lin­klater, et al., 2000)

Com­mu­ni­ca­tion and Per­cep­tion

In horses, the nos­trils, muz­zle, whiskers, and cheeks all have whiskers that are used to per­ceive the en­vi­ron­ment through touch. Vi­sion is the pri­mary means of per­ceiv­ing the en­vi­ron­ment in horses. Ears are long, slen­der, and up­right, which aid in au­di­tory per­cep­tion. Al­though their sense of smell is im­por­tant, it is not the chief means of per­cep­tion and pro­vides a smaller role than vi­sion or the sen­si­tive re­cep­tors on the nos­trils, muz­zle, whiskers, or cheeks. (Ben­nett and Hoff­mann, 1999)

The pri­mary means of com­mu­ni­cat­ing with other horses is through vo­cal­iza­tions and ges­tures, par­tic­u­larly fa­cial ges­tures. Dur­ing the breed­ing sea­son, males may grunt or scream at one an­other, in ad­di­tion to stomp­ing and paw­ing at the ground in an ag­gres­sive man­ner. Males may neigh to fe­males in es­trous and fe­males may squeal and kick if they are re­fus­ing a rut­ting male. Grunt­ing and ag­gres­sive ges­tures, in­clud­ing bit­ing, shov­ing, and kick­ing, may occur among herd mem­bers to es­tab­lish or re­in­force the hi­er­ar­chy struc­ture and ex­press dom­i­nance. Sub­mis­sive in­di­vid­u­als will let the win­ner lay their head on the loser’s back-end, which is seen in equids. (Ben­nett and Hoff­mann, 1999)

In ad­di­tion to body ges­tures, horses have an array of fa­cial ges­tures. Pos­i­tive re­ac­tions in­clude rais­ing of the lips to ex­pose upper teeth, sim­i­lar to a smile, and head bob­bing or point­ing the ears for­ward and erect. Ag­gres­sive fa­cial ges­tures in­clude the ears being laid back and the nos­trils closed while ex­pos­ing the same teeth. (Ben­nett and Hoff­mann, 1999)

• Communication Channels
• visual
• tactile
• acoustic
• chemical

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Pri­mar­ily fo­li­vores by na­ture, horses pri­mar­ily graze on true grasses. Do­mes­tic horses are often fed var­i­ous amounts of grains, in­clud­ing oats, bar­ley, corn, wheat, flax, soy­beans, al­falfa, clover, Tim­o­thy hay, and John­son grass. In ad­di­tion to this diet, they may also be pro­vided vi­t­a­min and min­eral sup­ple­ments. Feral horses eat a sim­i­lar diet, in­clud­ing Russ­ian this­tle, dropseed grasses, mesquite, prairie june­grass, green spran­gle­top, and salt­bush, and likely varies de­pend­ing on lo­ca­tion and sea­son. (Ben­nett and Hoff­mann, 1999; En­s­minger, 1969; Hansen, 1976)

• Primary Diet
• herbivore
  • folivore

• Plant Foods
• leaves
• wood, bark, or stems
• seeds, grains, and nuts

Pre­da­tion

Nat­ural preda­tors of wild horses are likely to have been mainly wolves, coy­otes, and moun­tains lions. Preda­tors mainly prey on el­derly, ill, or young an­i­mals. When a herd is threat­ened by a preda­tor, the alpha male may at­tack it through bit­ing and kick­ing with the hooves. Fe­males pro­tect their young in a sim­i­lar man­ner. Hu­mans are also preda­tors of horses, both his­tor­i­cally and cur­rently. Wild pop­u­la­tions were prob­a­bly hunted by hu­mans and horse meat is con­sumed in some places. (Ben­nett and Hoff­mann, 1999)

• Known Predators

  • gray wolves (Canis lupus)
  • coyotes (Canis latrans)
  • mountain lions (Puma concolor)
  • humans (Homo sapiens)

Ecosys­tem Roles

The do­mes­ti­ca­tion of horses con­tributed to the de­vel­op­ment of agri­cul­tural so­ci­eties and changed the mo­bil­ity and po­lit­i­cal re­la­tion­ships be­tween dif­fer­ent human pop­u­la­tions. As graz­ing an­i­mals, horses in­flu­ence di­ver­sity and struc­ture of the ecosys­tems in which they live. In some places horses have been im­por­tant in seed dis­per­sal of cer­tain trees. There are over 150 species of par­a­sites doc­u­mented in horses. (Ben­nett and Hoff­mann, 1999; Hardin, 1997)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Horses are eco­nom­i­cally very im­por­tant to hu­mans now and his­tor­i­cally. They have been used as a food source, have been crit­i­cal in the trans­porta­tion of peo­ple and goods, have played im­por­tant roles in mil­i­tary cam­paigns, in sport and recre­ation, and in agri­cul­tural de­vel­op­ment. Horses are also beloved com­pan­ion an­i­mals and widely used in ther­a­peu­tic ap­proaches. In agri­cul­ture, horses are used to pull plows and car­riages and their ma­nure is an im­por­tant fer­til­izer. Horse hairs are used in var­i­ous prod­ucts. (En­s­minger, 1969)

• Positive Impacts
• pet trade
• food
• body parts are source of valuable material
• research and education
• produces fertilizer

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Feral horse pop­u­la­tions may be dis­rup­tive to ecosys­tems that are not adapted to the pres­ence of large equid graz­ers. They can com­pete with other graz­ing an­i­mals for re­sources and cause ex­ces­sive dam­age to na­tive veg­e­ta­tion. Stud­ies show horses suc­cess­fully out­com­pete other graz­ing species. Wild, feral, and do­mes­tic horses can also trans­mit zoonotic dis­eases, which can cause neg­a­tive im­pacts to local an­i­mal species, agri­cul­ture, and peo­ple. ("Pest an­i­mal risk as­sess­ment: Feral horse (Equus ca­bal­lus)", 2009; Ben­nett and Hoff­mann, 1999)

• Negative Impacts
• injures humans
• causes or carries domestic animal disease

Con­ser­va­tion Sta­tus

Do­mes­ti­cated horses are abun­dant in many areas around the world. Their clos­est rel­a­tives, Prze­wal­ski's wild horses were listed as en­dan­gered on the IUCN Red List, en­dan­gered under the U.S. En­dan­gered Species Act, and on Ap­pen­dix I of CITES. Some older stud­ies state that do­mes­ti­ca­tion and re­lease of do­mes­tic horses led to this de­cline in Prze­wal­ski's wild horse pop­u­la­tions and they were thought to no longer exist in the wild. Cur­rent con­ser­va­tion ef­forts in Prze­wal­ski's wild horses in­clude legal pro­tec­tion of the species in Mon­go­lia as well as rein­tro­duc­tion ef­forts in sev­eral areas. (Ben­nett and Hoff­mann, 1999; Boyd and King, 2014)

• IUCN Red List

  Endangered No special status

• US Federal List

  Endangered No special status

• CITES

  Appendix I No special status

Other Com­ments

It is im­por­tant to note that there have been some tax­o­nomic changes that may af­fect the va­lid­ity of in­for­ma­tion in the older lit­er­a­ture on horses. Many older lit­er­a­ture sources con­sider Prze­wal­ski’s wild horses as the wild sub­species of horses, and refer to it as E. c. prze­wal­skii; how­ever, re­cent sources and the IUCN Red List con­sider Prze­wal­ski's wild horses as Equus ferus prze­wal­skii and sug­gests that E. f. prze­wal­skii is not the an­ces­tor of E. ca­bal­lus due to a dif­fer­ence in chro­mo­some num­bers. It is thought that they de­scended from dif­fer­ent lin­eages, but this tax­o­nomic de­bate is on­go­ing. It is dif­fi­cult to make this clar­i­fi­ca­tion due to the near ex­tinc­tion of the Prze­wal­ski's wild horses, pro­duc­ing a bot­tle­neck in ge­netic di­ver­sity. The cur­rent pop­u­la­tion of Prze­wal­ski's wild horses is de­scended from 13 cap­tive in­di­vid­u­als, one being a do­mes­tic horse and one being a hy­brid be­tween a do­mes­tic horse and a Prze­wal­ski's wild horse. In the mean­time, much older lit­er­a­ture does not dis­tin­guish be­tween wild E. ca­bal­lus and Prze­wal­ski's wild horses. Much in­for­ma­tion avail­able might ac­tu­ally be for both sub­species. (Ben­nett and Hoff­mann, 1999; Boyd and King, 2014; Wall­ner, et al., 2003)

Con­trib­u­tors

Christo­pher Clement (au­thor), Uni­ver­sity of Alaska Fair­banks, Laura Prugh (ed­i­tor), Uni­ver­sity of Wash­ing­ton, Tanya Dewey (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Biose­cu­rity Queens­land. Pest an­i­mal risk as­sess­ment: Feral horse (Equus ca­bal­lus). PR09-4511. Bris­bane: The State of Queens­land, De­part­ment of Em­ploy­ment, Eco­nomic De­vel­op­ment and In­no­va­tion. 2009.

Ben­nett, D., R. Hoff­mann. 1999. Equus ca­bal­lus Lin­naeus, 1758. Mam­malian Species, No. 628: 1-14.

Boyd, L., S. King. 2014. "Equus ferus ssp. prze­wal­skii" (On-line). The IUCN Red List of Threat­ened Species. Ac­cessed No­vem­ber 02, 2014 at www.​iucnredlist.​org/​details/​7961/​0.

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