Ammotragus lervia (Pallas, 1777)

Don E. Wilson & Russell A. Mittermeier, 2011, Bovidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 444-779 : 670-671

173.

Aoudad

Ammotragus lervia

French: Aoudad de Barbarie / German: Mahnenschaf / Spanish: Arrui

Other common names: Arrui, Audad, Barbary Sheep

Taxonomy. Antilope lervia Pallas, 1777 ,

N Africa.

The Aoudad has been hypothesized to be the ancestral form of sheep ( Ovis ) or goat ( Capra ), but their evolutionary relationships remain in question. The Aoudad has a diploid chromosome number of 58, identical to the Ladakh Urial (O. vigner), but has anatomical similarities to goats. Immunoglobulin and seroprotein analyses and the sequence of amino acids of several hemoglobin chains do not reveal clear evolutionary relationships. Aoudads will interbreed with goats but not with sheep, and molecular data reveal a closer relationship to goats. Six subspecies have been described, but their validity needs clarification.

Subspecies and Distribution.

A.l.lerviaPallas,1777—Morocco,NA.l.,andNTunisia.

A.l.angusiRothschild,1921—NWNiger(Air&TermitMassifs).

A.l.blaineiRothschild,1913—SELybia,NEChad,andNW&NESudan(probablynowrestrictedtoRedSeahills).

A.l.fassiniLepri,1930—NWLibya,extremeSTunisia.

A.l.ornatus1.GeoffroySaint-Hilaire,1827—SE&SWEgypt.

A. l. sahariensis Rothschild, 1913 — S Morocco, Western Sahara, NW Mauritania, S A.l ria, extreme S Libya, NE Mali, SE Niger, and NW Chad.

Introduced, free-ranging populations occur in S Spain, the Canary Is, USA (California, New Mexico, and Texas), and NE Mexico. Subspecies of free-ranging introduced populations are unknown because they originate from zoo animals of uncertain origin or from hybrids. Most introduced populations are probably from subspecies lervia , derived from European zoos. The Aoudad has become a widespread invasive species.

Descriptive notes. Head—body means 128 cm (males) and 112 cm (females), tail 17-5— 20-5 cm, shoulder height 92-110 cm (males) and 80-85 cm (females); weight means 82 kg (up to 145 kg) for males and 41-3 kg (up to 86 kg) for females. Measurements and weights are from captive specimens; wild individuals probably are smaller. The Aoudad has a pale tawny brown or rufous body color and dark brown areas about the head and forequarters. The chin, undersides, and inside of legs are whitish. A short, erect hair line extends from the base of the neck to just behind the withers. Adult males have prominent long hairs on the cheeks, the throat, and the front of the neck, extending to the brisket. A unique feature is the long hair on the anterior of the upper part of the front legs. The hairs on the brisket and legs can extend to the ground. Long hair is not as well developed in females. The tail is terminally tufted and naked underneath. Males and females possess horns that grow upward and then curve downward. The longest recorded male horn length, basal circumference, and tip-to-tip spread of a specimen from Africa measured 87-9 cm, 33-2 cm, and 39-4 cm, respectively. Specimens have been recorded in the USA with horns up to 50 cm. Horns of females are less massive but can be equally long.

Habitat. No ecological studies have been conducted in Africa; ecological data are from introduced populations. Aoudads in Africa occur from arid to semi-arid mountainous, rugged, broken terrain to open forests with a precipitous component. Introduced populations do well in a variety of habitats, including montane habitats associated with canyons and gorges, level terrain with brushy vegetation, and woodlands and grasslands, but Aoudads prefer precipitous terrain. They can survive in areas without rainfall. In Africa, they are found at elevations from near sea level to 4000 m. In New Mexico, USA, they occur from less than 1000 m to 2312 m. In California, in a Mediterranean climate, Aoudads used woodlands in summer, grasslands in autumn and winter, and rugged terrain in spring, during the lambing period. In Spain, in an area consisting of three habitats (open with shrubs, closed formed by forests, and mixed habitats consisting of shrubs with scattered trees), neither adult females nor subadults showed preference for a particular habitat. During the parturition period, no animals of either sex were observed in closed forest; males were most frequently sighted in mixed habitats and females in open shrub habitats. During the mating season, in October, Aoudads were mostly observed in closed rather than open habitats. Population parameters and habitat use can be variable due to variability in population size, habitats, and rainfall and forage production within and between years.

Food and Feeding. In north-eastern New Mexico, diets from rumen analyses consisted of 64% browse in summer, 58:4% browse in autumn, 86% grass in winter, and 59-9% browse in spring. Mountain mahogany (Cercocarpus breviflorus) and wavyleaf oak (Quercus undulata ) were the browse species consumed. Mountain mahogany constituted 54-3% of diets in the summer and 31-5% in the autumn. Wavyleaf oak constituted 30% of forage in summer and 54-3% during autumn. On an annual basis, browse constituted 48%, grasses 41%, and forbs 9% of diets. In western New Mexico, annual diets were 42% browse, 38% forbs, and 10% grasses. In west-central Texas, diets consisted principally of forbs and grasses. Aoudads adjust to available forage, but browse is their principal food source in arid regions.

Breeding. Females usually first mate at 18 months. The main rut occurs in September— November. During rut, older males from formerly segregated herds search and court individual females and guard estrous females from other males. Prior to parturition, females isolate themselves in rugged terrain. After a gestation of 155-165 days, they give birth to one or two offspring. In New Mexico, twinning ranged from 22% to 58%. Only multiparous females produce twins. Birth weights are 3.1-4 kg. Females do not rejoin herds until the neonate is able to follow their mother, usually within two days. Most births occur in March-April but parturition can occur in other months within a population. In captive populations, high-ranking females have shorter interbirth intervals and produce a higher proportion of twins, male calves, and heavier calves. They wean their calves earlier, produce heavier male neonates, and only they have male twins.

Activity patterns. Aoudads are mostly diurnal, but their grazing periods can be equally divided between night and day. When disturbed by humans, feeding activity will shift to night. There is an increasing period of inactivity during the day from winter to summer. During warm weather, Aoudads rest in shaded areas. Rough, steep terrain is used significantly more for resting sites.

Movements, Home range and Social organization. Daily movements of three Aoudads ranged from 0-2 km to 3-4 km. Diurnal movements ranged from 0 km to 1-9 km, without significant differences between seasons. Annual home ranges of two rams averaged 1547 ha and the home range of one female was 764 ha, indicating that males have larger home ranges than females. Released animals dispersed 32-3 km within 5-7 months. Abrupt seasonal movements of up to 23-4 straight-line km are known. Aoudads are gregarious and develop a dominance hierarchy within herds, but individual female rank can change depending on age and reproductive history. Mixed herds composed of adult males and females, subadults, and young usually formed during rut, have 2-63 animals, with a mean size of 14-7. Nursery and mixed herds in a population of 500-600 have 2-45, with a mean of 7-9. In another study, mean group size declined from 25 after the rut to five in the summer and increased during the autumn and winter, especially during the rut, when adult males joined female herds. In a captive population study, the higher the relatedness and age similarity, the closer the distance between individuals, indicating an ability to recognize close relatives. One population consisted of 30% juveniles and subadults, 20% males, and 50% females. Survival rates were 35% for the neonate to one-year-old cohort, 77% per year for males 1-3-5 years of age, and 55% for males 3-5-10-5 years of age. Longevity in the wild is 10-12 years and in captivity 24 years. In the introduced populations in America predators include Coyotes (Canis latrans) and Pumas (Puma concolor ), but predation is usually not a significant mortality factor in the USA or Spain. Although diseases and parasites are usually insignificant causes of mortality, there have been population die-offs caused by a helminth nematode (Elaeophora schneideri) in the USA and mange (Sarcoptes scabiei) in Spain. The greatest adult mortality factor in the USA is sport hunting.

Status and Conservation. CITES Appendix II. Classified as Vulnerable on The IUCN Red List. An estimated 5000-10,000 Aoudads occur in Africa. They have undergone widespread extirpations and population decreases throughout most of their former range, including Egypt, Sudan, Libya, Chad, and Western Sahara. Present distribution and status over much of their range is unknown. Major threats are illegal hunting and habitat degradation and destruction due to livestock overgrazing and human disturbance. Feral camels can be forage competitors. Conservation measures include reestablishing extirpated populations, establishing protected areas with strict law enforcement and exclusion of livestock, and developing monitoring programs. Free-ranging, introduced Aoudad populations are a major management concern because of their potentially deleterious impacts on native wildlife such as deer and especially native Bighorn Sheep ( Ovis canadensis ) in the USA and Mexico and the Iberian Ibex ( Capra pyrenaica ) in Spain. Estimates are 12,000 in Texas, 4000 in New Mexico, 400 in California, probably fewer than 1000 in Mexico, more than 1000 in Spain, and hundreds in the Canary Islands. Most introductions were for the purpose of developing sporthunting programs; they are protected in private game preserves, from which they can escape and spread. Their high birth rate, adaptability to a wide variety of habitats and foods, lack of significant predation, resistance to native and domestic animal diseases, and their potential for being vectors of diseases all pose management challenges. There is a high potential for space and forage competition with native wildlife. They are capable of dispersing widely within short periods. They are a concern to federal and state agencies in the USA because of their spread into national forests, parks, and wildlife refuges. Bighorn Sheep are susceptible to die-offs from diseases transmitted from domestic sheep. Because Aoudads can thrive in areas grazed by domestic sheep and other domestic ungulates and are potential vectors of domestic sheep diseases, they are a threat to Bighorn Sheep. Aoudads are highly effective colonizers and thrive in desert habitats of Bighorn Sheep. In areas where Bighorn Sheep were extirpated, the presence of Aoudads precludes the reintroduction of Bighorn Sheep. Because the Aoudad and the Mule Deer (Odocoileus hemionus) have similar food habits, there is potential for forage competition between the two species. The same concerns apply to the Aoudad relative to the Iberian Ibex and other native ungulate species in Spain. In some cases, Aoudads should be eradicated or controlled to limit negative effects on native fauna and plants.

Bibliography. Acevedo, Cassinello, Hortal & Gortazar (2007), Bird & Upham (1980), Bunch et al. (1977), Cabrera (1932), Cassinello (1996, 1998, 2000), Cassinello & Alados (1996), Cassinello & Calabuig (2008), Cassinelo & Gomendio (1996), Cassinello, Acevedo & Hortal (2006), Cassinello, Cuzin et al. (2008), Cassinello, Serrano, Calabuig, Acosta & Pérez (2007), Cassinello, Serrano, Calabuig & Pérez (2004), Dickinson & Simpson (1980), Gray (1985), Hight & Nadler (1976), Johnston (1980), Manwell & Baker (1975), Mereu et al. (2008), Mungall (2000), Nadler, Hoffmann & Woolf (1974), Ogren (1965), Pence (1980), Pirastru et al. (2009), Rangel-Woodyard & Simpson (1980), Simpson et al. (1980),Valdez & Bunch (1980), Wacher et al. (2002).

Figures

167. Chiru (Pantholops hodgsonii), 168. Rocky Mountain Goat (Oreamnos americanus), 169. Mishmi Takin (Budorcas taxicolor), 170. Bhutan Takin (Budorcas whitei), 171. Sichuan Takin (Budorcas tibetana), 172. Golden Takin (Budorcas bedfordi), 173. Aoudad (Ammotragus lervia), 174. Arabian Tahr (Avabitragus jayakari), 175. Himalayan Tahr (Hemutragus jemlahicus), 176. Greater Blue Sheep (Pseudois nayawr), 177. Dwarf Blue Sheep (Pseudois schaeferi)

Subspecies and Distribution. A.l.lerviaPallas,1777—Morocco,NA.l.,andNTunisia. A.l.angusiRothschild,1921—NWNiger(Air&TermitMassifs). A.l.blaineiRothschild,1913—SELybia,NEChad,andNW&NESudan(probablynowrestrictedtoRedSeahills). A.l.fassiniLepri,1930—NWLibya,extremeSTunisia. A.l.ornatus1.GeoffroySaint-Hilaire,1827—SE&SWEgypt. A. l. sahariensis Rothschild, 1913 — S Morocco , Western Sahara , NW Mauritania , S A.l ria, extreme S Libya , NE Mali , SE Niger , and NW Chad . Introduced, free-ranging populations occur in S Spain , the Canary Is, USA (California, New Mexico, and Texas), and NE Mexico. Subspecies of free-ranging introduced populations are unknown because they originate from zoo animals of uncertain origin or from hybrids. Most introduced populations are probably from subspecies lervia , derived from European zoos. The Aoudad has become a widespread invasive species.