Specimen of the Week: Week 161

Last week, my colleague Jack Ashby wrote in effort to promote the under-promoted in the animal kingdom –the non-superstars that do not, at first glance, appear to be particularly special or worthy of fame and fortune. This week I would like to advance this theme by highlighting an animal that is often overlooked as not only a superstar but a veritable animal superhero.

This week’s Specimen of the Week is…

**The Rock Hyrax**

Yes, the dynamism of this specimen brings to mind the soaring action of Superman, Supergirl, Red Tornado or Ironman. This pose, however, is a result of this rock hyrax specimen being a study skin. No, it’s not just bad taxidermy. Study skins (usually of birds or small mammals) are a way to preserve specimens. The skin is removed, dried (with heat or chemicals), treated with absorbents and filled with cotton or polyester batting (in the past, plant fibres or sawdust). Wooden or metal supports may be placed inside to support legs/tails. They retain useful morphological features and are easier to prepare and store than taxidermy.

Unnatural posture aside, the rock hyrax is a remarkable animal and shares undeniable traits common to all the greatest superheroes:

1). A secret identity At first glance, hyraxes appear to be no more than cute little balls of fur, a bit heftier than guinea pigs. They are most likely to be seen by us mere mortals basking in the sun on the rocky outcrops of Table Mountain in Cape Town. The ability to blend in and not be noticed is achieved by their brown/light grey coats, perfectly camoflaging the hyrax in their natural habitat of rocky scrubland and dry savannah. But don’t be fooled by their lazy demeanor and squat, short-legged build. Rock hyraxes are able to nimbly squeeze into rocky nooks and navigate sheer cliffs with ease.

2). Extraordinary powers and abilities and/or advanced equipment Rock hyraxes have special feet adapted for rock climbing. The bottom of each foot is bare and has a moist, rubbery pad that lifts up in the center for a suction-cup effect to help the hyrax cling to rocks and smooth surfaces. Hyraxes also have special feeler-like hairs used to help guide the animal in the same way a cat uses its whiskers as well as a special eyelid (umbraculum) which acts as a sunshade (1).Unique to hyraxes is the dorsal gland which excretes an odour used in communication and territorial marking (2).

3). A willingness to risk one’s own safety in the service of good Hyraxes live in harem groups consisiting of one territorial male and up to 20 females and their young. As leader of the group, the dominant male exhibits a strong sense of responsibility for his family – keeping watch for predators and fiercely protecting the group’s area from ill-meaning rival males. During feeding (whereby the group will eat in a circle formation with heads pointing out to keep watch for any possible threats), the dominant male will stand apart, unprotected, sounding alarm if needed (3).

4). Headquarters or base of operations Superheroes need their hideouts and the hyrax is no exception. Geographically, the range of rock hyraxes is throughout most of sub-Saharan Africa and extending along the coast of the Arabian peninsula up to Lebanon. As their name implies, the rock hyrax occupies habitats dominated by rocks and boulders whereby it can find cavities and crevices that are large enough to shelter in, but small enough to prevent entrance by predators. Given their poorly developed thermoregulation, hyraxes use basking and sheltering to control their body temperatures. Thus their lairs need access to both deep crevices to excape the heat and safe, sunlit areas when it is cold.

5). A backstory that explains the circumstances by which the superhero acquired his/her abilities Hyraxes are the only living members within the order Hyracoidea within the larger taxon Paenungulata which includes Proboscidea (elephants) and Sirenia (sea cows, dugongs and manatees). Sharing a common ancient ancestor, the hyrax’s closest cousins are elephants and as such, they share some unusual characteristics. Look closely and you’ll notice that hyraxes have mini tusks which have developed from their incisor teeth (not from canines like other tusked animals). They have flat, hoof-like nails on their toes rather than claws. Hyraxes (also like elephants) have testes that do not descend into a scrotum and remain in the abdominal cavity.

Hyraxes are also believed to be highly intelligent animals – their many vocalisations and songs are highly complex and use syntax (the order of different syllables put together in a song are significant) (4). They are even recognised in the bible as being exceedingly wise “the rock badgers are a people not mighty, yet they make their homes in the cliffs” (5).

Tannis Davidson is Curatorial Assistant at the Grant Museum of Zoology

References

1. Johnson, George L. 1900. ‘Contributions to the Comparative Anatomy of the Mammalian Eye Chiefly Based on Ophthalmoscopic Examination’, Communicated by H. Gadow, F.RM.
2. Olds, N., J. Shoshani. 1982. Mammalian Species Procavia capensis. American Society of Mammalogists, 171: 1-7.
3. Estes, R. 1991. The Behavior Guide to African Mammals. Berkeley: The University of California Press.
4. Kershenbaum, A., Ilany, A., Blaustein, L., and Geffen, E. 2012. Syntactic structure and geographical dialects in the songs of male rock hyraxes. Proc. R. Soc. B. 279: 2974-2981.
5. Proverbs 30:26, ESV