Rock Hyrax - Closest living relative to the elephant.
Hyraxes typically live in groups of 10â80 animals, and forage as a group. They have been reported to use sentries: one or more animals take up position on a vantage point and issue alarm calls on the approach of predators.
The rock hyrax has incomplete thermoregulation, and is most active in the morning and evening, although their activity pattern varies substantially with season and climate.
Prominent in and apparently unique to hyraxes is the dorsal gland, which excretes an odour used for social communication and territorial marking. The gland is most clearly visible in dominant males.
The head of the rock hyrax is pointed, having a short neck with rounded ears. They have long black whiskers on their muzzles. The rock hyrax has a prominent pair of long, pointed tusk-like upper incisors which are reminiscent of the elephant, to which the hyrax is distantly related (see below). The forefeet are plantigrade, and the hindfeet semi-digitigrade. The soles of the feet have large, soft pads that are kept moist with sweat-like secretions. In males, the testes are permanently abdominal, another anatomical feature that hyraxes share with their relatives elephants and sirenians.
Thermoregulation in the rock hyrax has been subject to much research, as their body temperature varies with a diurnal rhythm. However, animals kept in constant environmental conditions also display such variation and this internal mechanism may be related to water balance regulation.
Rock hyraxes are very noisy and sociable. Adults make use of at least 21 different vocal signals. The most familiar signal is a high trill, given in response to perceived danger. Rock hyrax calls can provide important biological information such as size, age, social status, body weight, condition, and hormonal state of the caller, as determined by measuring their call length, patterns, complexity, and frequency. More recently, researchers have found rich syntactic structure and geographical variations in the calls of rock hyraxes, a first in the vocalization of mammalian taxa other than primates, cetaceans, and bats.
The rock hyrax also makes a loud grunting sound while moving its jaws as if chewing, and this behaviour may be a sign of aggression. Some authors have proposed that observation of this behavior by ancient Israelites gave rise to the misconception given in Leviticus 11:4-8 that the hyrax chews the cud; in fact, hyraxes are not ruminants.
The rock hyrax spends approximately 95% of its time resting. During this time, they can often be seen basking in the sun, which is thought to be an element of their complex thermoregulation.
- Hell's Gate National Park, Kenya