| Alpine Ibex | |
|---|---|
| Male | |
| Female | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Family: | Bovidae |
| Genus: | Capra |
| Species: | C. ibex |
| Binomial name | |
| Capra ibex Linnaeus, 1758 |
|
| Range map in the Alps | |
The Alpine ibex, (Capra ibex), is a species of wild goat that lives in the mountains of the European Alps. In its habitat region, the species is known as bouquetin (French), Steinbock (German), and stambecco (Italian).
The Spanish ibex (Capra pyrenaica) and the Middle Eastern Nubian ibex (Capra nubiana) are very close relatives of the Alpine ibex, and were formerly considered to be subspecies. Fossils of Alpine ibex dating back to the late Pleistocene, when it and the Spanish ibex probably evolved from the extinct Pleistocene species Capra camburgensis.[2]
Contents |
Compared with other members of its genus, the Alpine ibex has a short, broad head and a duller coat pattern. It has brownish grey hair over most of the body, with slightly darker markings on the chin and throat, and in a stripe along the back, and a pale abdomen. They moult twice a year, firstly in April or May, and then again in September, when they replace the short summer coat with thicker hair and a woolly undercoat. As with all goats, males have beards, while females do not.[2]
Males commonly grow to a height of 90 to 101 centimetres (35 to 40 in) at the withers, with a body length of 149 to 171 centimetres (59 to 67 in) and weigh from 67 to 117 kilograms (150 to 260 lb). Females are noticeably smaller, with a shoulder height of 73 to 84 centimetres (29 to 33 in), a body length of 121 to 141 centimetres (48 to 56 in), and a weight of 17 to 32 kilograms (37 to 71 lb). Both male and female Alpine ibexes have large, backwards-curving, horns with numerous ridges along their length. At 69 to 98 centimetres (27 to 39 in), those of the males are substantially larger than those of females, which reach only 18 to 35 centimetres (7.1 to 14 in) in length.[2]
The Alpine ibex was, at one point, restricted only to the Gran Paradiso national park in northern Italy, but in recent years it has recolonised most of the European Alps, and is found in Italy, France, Germany, Switzerland, Austria, and Slovenia.[1] There are currently no recognised subspecies.
Being an excellent climber, its habitat is the rocky region along the snowline above alpine forests, where it occupies steep, rough terrain at elevations of 1,800 to 3,300 metres (5,900 to 10,800 ft).[3] Alpine ibex tend to avoid large woodland areas.[2] However, in areas of high population densities, adult males will use larch and mixed larch-spruce woodland most of the year.[4] In one area they are also found in areas of coniferous forest.[2] Males and females tend to use different habitats most of the year.[5] Females are more reliant on steep terrain than males.[6] Males use meadows of low-elevation during the spring, which is when snow melts and green grass appears.[6] They then move to alpine meadow of higher elevation during the summer.[4] When winter arrives, both sexes move to steep rocky slopes that amass minimal amounts of snow.[7] During this time, ibex inhabit slopes of 30-45° and will use small caves and overhangs for shelter.[8] The home ranges of herds are highly variable, depending on the availability of resources, and may also vary in size throughout the year. Figures of anything from 180 to 2,800 hectares (440 to 6,900 acres) have been recorded.[2][7] Home ranges tend to be larger during summer and autumn, smaller in spring and smallest in winter.[2] Female home ranges tend to be smaller than those of males.
Alpine ibexes are strictly herbivorous, with over half of their diet consisting of grasses, and the remainder being a mixture of moss, flowers, leaves, and twigs.[2] If leaves and shoots are out of reach, they often stand on their rear legs to reach this food. Grass genera that are the most commonly eaten are Agrostis, Avena, Calamagrostis, Festuca, Phleum, Poa, Sesleria and Trisetum.[2] The need to drink every few days in the summer causes the animals to seek permanent residence close to a dependable water source during this season. Alpine ibexes will hide in the rocks of the steep cliffs when pursued by predators. The climbing ability of the Alpine ibex is such that it has been observed standing on the sheer face of a dam, where it licks the stonework to obtain mineral salts.[9]
Although the Alpine ibex is gregarious, there exists sexual and spatial segregation depending on the season.[6] Four types of groups exist. Adult male groups, groups made of females and their dependent offsping, groups made of young individuals of 2–3 years old and mixed sex groups.[2][10] Young groups are common at the beginning of summer and are displaced by females about to give birth. Female and offspring groups can be sighted throughout the year, at least in an area of the French Alps.[10] Mixed sex groups of adult males and female occur during breeding, which lasts from December to January. By April and May, the adult of both sexes completely segregate.[10] The largest aggregations of either sex, occur in late spring and summer, during June and July. Aggregations of males decrease in autumn, during October and November, and are lowest from the rut to early spring, from December to March.[10] The males then aggregate again from their separate wintering areas.[11]
There is a linear dominance hierarchy among males. In small populations, male ibex know their place in the hierarchy based on memories of past encounters in cohesive social units[2] while in mobile and large groups, where encounters with strangers are common, rank is based on horn length.[12] Ibex males display two types of antagonistic behavior: direct and indirect aggression. With direct aggression, a male will make physical contact with another, whether with the blunt parts of the horns or tips or by jumping on its hind legs in front of its opponent and them coming down forward thrusting the horns. This may signal that it is ready to clash or it may be attempting a real clash.[2] Clashing requires synchronization of both combatants and is most common between males of the same age class. Indirect aggression including displays such as an individual holding up its head to make itself look bigger or when two individuals walk in parallel with their horns tipped towards each other. Males of equal rank will run shoulder to shoulder, but if one is subordinate, he will take the lead.[2]
The breeding season starts in December, and typically lasts around six weeks. During this time, male herds break up into smaller groups that travel in search of females. The rut takes place in two phases. In the first phase, the male groups interact with the females who are all in estrous. The males approach the females in a low stretch and stand at a distance proportional to their social rank.[2] They will also perform other courtship displays. In the second phase of the rut, a male will detach himself from this group and follow an individual female. He performs the low stretch and will threaten any male that approaches. Before copulation, the female will move her tail and courtship becomes more intensive. The male will then copulate with the female and then join his group and revert back to the first phase.[2] Gestation lasts around 167 days, and results in the birth of one or two kids, with twins making up about 20% of births.[13]
Alpine ibex reach sexual maturity at eighteen months, but females do not reach their maximum body size for five to six years, and males not for nine or eleven years. The horns grow throughout life, growing most rapidly during the second year of life, and thereafter by about 8 centimetres (3.1 in) a year, eventually slowing to half that rate once the animal reaches ten years of age. Alpine ibex have been reported to live for up to nineteen years in the wild[14]
The Alpine ibex has historically ranged though France, Italy, Switzerland, Lichtenstein, Bavaria, Austria and Slovenia. Starting in the early 1500s the overall population declined due to overexploitation and poaching and the ibex became extinct in Switzerland, Germany and France by the 18th century. By the 19th century, ibexes became extinct in Austria and northeastern Italy. They remained only in the area of the Gran Paradiso Massif in the western Italian Alps.[2] The Gran Paradiso was established as a royal hunting reserve in 1854 by Vittorio Emanuele II. The ibex were protected from poaching and their population increased to about 3,020 by 1914. In 1922, Gran Paradiso was made into a national park to protect the ibex. Animals from this stock where introduced to other areas. By 1976, the number of extant populations in the European Alps was about 104.[2] Today, the total population of Alpine ibex is over 20,000[15] and is considered to be of Least Concern.[1]