A few weeks ago, I went hiking in the mountains of Madrid (Spain) in the hope of encountering, with a bit of luck, a herd of Iberian ibex (Capra pyrenaica). At this time of year, ibex are particularly active because it is the mating season, which significantly increases the chances of observing them in their natural habitat. Fortune smiled upon me, and I was able to observe a very large herd. Inspired by this experience, I decided to write this post with everything you need to know about this remarkable animal.
Distribution and threats
The Iberian ibex is an ungulate—that is, an animal that walks on the tips of its toes, which are protected by hooves. It belongs to the family Bovidae, the same family as cattle and sheep.
Until the 19th century, the Iberian ibex was distributed across most of the mountain systems of the Iberian Peninsula. However, various pressures and threats drastically reduced its range, which is now limited to mountain ranges in the eastern, central, and southern parts of the peninsula. Fortunately, populations are currently expanding thanks to reintroduction efforts. According to the latest assessment by the International Union for Conservation of Nature (IUCN), its conservation status is Least Concern.
The main threats currently faced by Iberian ibex populations include habitat disturbance, poaching, competition for resources with domestic livestock and non-native wild ungulates such as the Barbary sheep (Ammotragus lervia), tourism pressure, imbalances in population age and sex structure, and the impact of diseases—especially sarcoptic mange (caused by the mite Sarcoptes scabiei), a highly contagious disease capable of drastically reducing populations.
Biology and sexual dimorphism
Like other bovids, the Iberian ibex is strictly herbivorous. Its diet includes a wide variety of plant species, both herbaceous and woody, some of them extremely fibrous. However, this poses little difficulty thanks to its ruminant digestion: its multi-chambered stomach and the mutualistic microorganisms it hosts allow it to break down even the toughest plant material.
The Iberian ibex has few natural predators. The main ones are the golden eagle and the red fox, which usually prey on unprotected young. Wolves were once significant predators as well, but today they pose little threat due to the limited overlap between their respective distribution ranges. As with many other species, humans remain its primary predator.
There is a pronounced sexual dimorphism between males and females, evident in several traits. One of the most notable is body size: males are larger and heavier than females, reaching up to 120 kg, compared to approximately 46 kg for females. Coat coloration also differs. Females tend to display cinnamon and ochre tones, whereas males develop black patches on their flanks and neck that expand with age, although these markings disappear when the coat is shed in summer.
Nevertheless, the most distinctive feature between the sexes is the horns, which are far more developed in males. Male horns are rough in texture, develop prominent knots, and tend to spread and curve into an S-shape, often reaching lengths of 70 to 90 cm. Female horns are much shorter, thinner, and straighter. In males, horn size and quality play a crucial role in competition for access to females. Typically, older males—with the most developed horns—enjoy priority access for mating. Horns also provide females with information about male reproductive quality. In fact, studies have found a strong correlation between horn quality and sperm motility. While females are not consciously aware of this relationship, well-developed horns are nonetheless associated with good genetic and reproductive quality, which explains why older males tend to be more successful during courtship.
Courtship and reproduction
One of the most fascinating aspects of the Iberian ibex is its complex courtship behavior and the wide range of displays it involves. The species is polygamous, meaning that a single male mates with multiple females. The mating season takes place between November and December.
Courtship begins with the establishment of a dominance hierarchy among males. Dominant individuals—typically the oldest—displace younger, less experienced males, thereby securing preferential access to females. Once dominance is established, males approach groups of females and begin courtship, often facing interference from rival males, which they must confront using their powerful horns to maintain their status.
Once rivals have been driven away and a potential mate selected, the male stretches his head and neck forward, tilts his horns backward, and raises his tail to expose the anal gland. This gland releases pheromones that stimulate ovulation and increase female receptivity. At the same time, the male stamps the ground with his foreleg, slowly approaches the female, and rapidly flicks his tongue up and down—often near the female’s genital area. This allows him to detect pheromones and determine whether the female is in estrus. This behavior, known as the Flehmen response, is common in many mammal species. Its purpose is to capture airborne chemical molecules and transfer them to the vomeronasal organ, a.k.a. Jaconsob’s organ, located between the nose and mouth, which is rich in nerve endings sensitive to these compounds. Through this mechanism, animals can assess the physiological state of their conspecifics, including whether a female is receptive.
Together, these actions form a sexual ritual that provides the male with information about the female’s reproductive state while allowing the female to assess the male’s intentions. When a female is not receptive, she may turn aggressively toward the male, threatening him with her small horns, and urination is also common. When receptive, she arches her back, slightly spreads her hind legs, and lifts her tail to expose her genitalia.
A common behavior among females in estrus is to make short runs to attract the attention of males, which respond by chasing them. When the female stops, males line up behind her according to the dominance hierarchy, from the oldest and most dominant to the youngest. Generally, the female will choose to mate with the oldest male. Younger males usually miss reproductive opportunities until they gain experience over several years.
Fertilized females give birth between April and June, usually to a single kid, although twins may occasionally occur. To give birth, females leave the herd and isolate themselves in steep, inaccessible areas that offer protection from predators. They later rejoin the group. Births are highly synchronized so that kids are born during the most favorable time of year, maximizing their chances of survival. If born too early, they may face late spring frosts; if born too late, they may fail to develop sufficiently to survive the following winter.
The Iberian ibex is one of the most emblematic inhabitants of our mountain landscapes. Its conservation—and that of its habitats—ultimately lies in our hands.
REFERENCES
Alados C.L., Escós J. (2017). Cabra montesa – Capra pyrenaica Schinz, 1838. Enciclopedia Virtual de los Vertebrados Españoles [online]. Available in: https://www.vertebradosibericos.org/mamiferos/cappyr.html
Ministerio para la Transición Ecológica y el Reto Demográfico (2007). Atlas y libro rojo de los mamíferos terrestres de España. Available in: https://www.miteco.gob.es/content/dam/miteco/es/biodiversidad/temas/inventarios-nacionales/ieet_mami_capra_pyrenaica_tcm30-99789.pdf
