努比亚北山羊种

努比亚羱羊是体型最小的一种羱羊，肩高约为70公分，为两性异形的物种，雄羊（52—74.7公斤）体型大于雌羊（25.3—32.7公斤）。本种主要以相思树与金合欢树叶为食，取食时可爬到树上；这种山羊具社会性，羊群由雌羊与小羊组成，羊群中的雌羊具阶级之分，成年雄羊则大多独立生活。

希伯来圣经即有许多关于努比亚羱羊的记载，圣经人物雅亿名称的意思即为羱羊。努比亚羱羊现为以色列自然公园管理局的标志。也门也将努比亚羱羊视为国家象征之一。

The Nubian ibex (Capra nubiana) is a desert-dwelling species of goat (genus Capra) found in mountainous areas of northern and northeast Africa, and the Middle East. Historically considered a subspecies of the Alpine ibex (C. ibex), it is now recognized as a distinct species. The wild population is estimated at 4,500 mature individuals, and it is classified as vulnerable by the International Union for Conservation of Nature.

Taxonomy

Classification

The Nubian ibex was first identified in modern science by Frédéric Cuvier in his 1825 Histoire naturelle des mammifères: avec des figures originales, coloriées, dessinées d'aprèsdes animaux vivans, in which he illustrated the animal with the label "Bouc sauvage de la Haute-Égypte" ("Wild goat of Upper Egypt"). It was initially classified as Capra ibex nubiana, a subspecies of the Alpine ibex (C. ibex) identified by Carl Linnaeus in 1758. Other early researchers classified it as a now-defunct synonym, C. sinaitica, or the Sinai ibex. While it was referred to as its own species, C.

Description

Nubian ibex are the smallest ibex species, following Bergmann's rule. They stand around 65–75 cm (26–30 in) tall at the shoulder. They are sexually dimorphic: males are significantly larger than females, with males averaging 52–74.7 kg (115–165 lb) and females 25.3–32.7 kg (56–72 lb).

They are a light tan color, with a white underbelly; males also have a dark brown mane down their backs. Their legs have a black and white pattern. They have a lighter rump with a dark brown tail. Males begin growing a beard at age 2 or 3, which continues to grow longer and darker as they age.

Distribution

Historically, Nubian ibex were distributed across the Middle East and Northeastern Africa.

Its range today is within Egypt, Jordan, Oman, Israel, Palestine, Saudi Arabia and Sudan. It was extirpated in Lebanon, though a captive breeding and reintroduction process is underway. It has been extirpated in Syria. Its presence is uncertain in Ethiopia, Eritrea and Yemen.

Ecology and behavior

Feeding

Nubian ibex live in rough, dry, mountainous terrain, where they eat mainly grasses and leaves, especially from Acacia trees (Genus Vachellia). They forage for food on the ground and may also rear up on their hind legs to reach leaves in trees. They can climb into trees while feeding. They reduce feeding on plants with strong defenses, such as tannins and thorns. Preferred plants vary depending on the amount of rain; rainy winters result in higher feeding preference for annual plants over perennials.

Physiology

Eyes and vision

Nubian ibex vision is adapted to navigating visually on mountainous terrain. A study of their retinal ganglion cell density shows that they share many traits with other artiodactyls: a temporal area, horizontal streak, and dorsotemporal extension. They have a potentially unique dorsotemporal area of high ganglion cell density that benefits vision in the lower visual field, helpful for navigating varied terrain. Additionally, they have a more loosely organized horizontal streak than other hoofed animals. Their tapetum lucidum is morphologically similar to that of goats.

Human impacts and conservation status

Human impacts

The International Union for Conservation of Nature (IUCN) has classified the Nubian ibex as "vulnerable" on the basis that fewer than 10,000 mature individuals remain and the population is declining. Threats faced by the animal include competition with livestock for water and fodder, hunting pressure, climate change, habitat fragmentation, chemical pollution, and habitat destruction.

Ecotourism and outdoor recreation may disturb ibex in nature reserves, causing them to change their behavior in order to avoid people.

Cultural significance

Ancient Middle Eastern cultures

Nubian ibex played an important role in cultures of the ancient Near East. They have been a common image in petroglyphs (rock art), metal work, pottery, and other artwork across the Middle East for thousands of years, with some artwork dating back to the late Pleistocene. One example is a life-sized image carved in sandstone in Egypt, dated to the Upper Paleolithic. In petroglyphs, ibex are often portrayed as hunted by dogs and human archers. They are also frequently depicted alongside celestial imagery such as a star, sun, cross, or circle.