Taita tree hyrax – mysterious relict species

(Dendrohyrax sp.)

I will never forget fist time that I heard tree hyrax. I was sitting on a log. It was first time I was in the forest after dark. I was companied by Kenya Forest Service ranger Jonam Mwandoe. Startling call, that seemed to come just to my ear, almost dropped me from the log. I asked what an earth was that?

Jonam told me about tree hyraxes, but I really didn’t understand. I had no idea that there could be relatives of elephants in the trees. For some time I thought of them as some peculiar rodents, which they really are not!

Each night in the forest had been filled with their vocalizations, where individuals counter call to another. But it took weeks to see one. At the time I had no idea how special this event was.

This individual, probably young female was first tree hyrax I saw. It was resting just about 4 meters above the ground. Females have smaller and rounder tusks.

Researchers just don’t see tree hyraxes. And this is probably why these animals are so neglected in science. Studying animals that you can’t see in difficult and challenging conditions and producing scientific articles with real data even more difficult.

As time went on I gathered more pictures and tons of recordings of their vocalizations. I became more and more intrigued by these mysterious animals. Then it really hit me:

Tree elephants!!!!

Hyraxes belong to Paenungulata, their relatives are elephants and manatees. How amazing and unbelievable group!

My supervisor, emeritus professor Simon Bearder pointed out from recordings, that these tree hyraxes are new species for the science.

Special features of tree hyraxes

Belong to Paenungulata with elephants and manatees
Small tusks
Teeth like rhinos
Dense fur
Three toes
Round body
Eat leaves, fibrous, low calorie diet
Slow metabolic rate
Complicated digestion system
Low body temperature
Internal testes
Whiskers around the body
Scent gland
Spends days in tree holes
Use toilets
Extremely variable vocal communication
Solitary
Nocturnal

Variable vocal communication suggests that this species has complex social behavior, even though they are solitary. Knowledge of these species and their behavior is very limited.

*This male is much larger and has bigger tusks.*

Ecological niche of tree hyrax is the same as koala and sloth

In some two largest forests of Taita Hills, Ngangao and Mbololo tree hyrax density is high. However total area of these forests are only three square kilometers. As density is high, young animals are forced to move out of forest, where they easy food for dogs.

Tree hyrax only lives in indigenous forest. It is dependent on tree cavities for safety

*Tree hyrax jumping from branch to another. Thinking and hesitating took minutes before actual jump.*

How tree hyraxes can live in the canopy of tall mountain rain forest is amazing. Animal is heavy, it has only tree toes. It seems like species that is taken out of their real environment.

One form of protection for this species could be to build artificial nest in areas, where are trees, but no tree cavities. However replanting of indigenous forest and building corridors between fragments is necessary for long term survival of this species.

*This sweet female was observing us from close range, she was possibly moving on to new tree.*

These unknown tree hyraxes are in serious threat by human development all over Africa, not just in Taita Hills. Different species of tree hyraxes are possibly going extinct even before they are identified.

Mammals of Africa (2013):
“Major revision of this group is overdue”

*Eastern tree hyrax (Dendrohyrax validus) drawing from Mammals of Africa (Kingdon 2013).*

“Taita tree hyrax desperately needs taxonomic identification and conservation”

Sources:

Cordeiro, Norbert J., Nathalie Seddon, David R. Capper, Jonathan M. M. Ekstrom, Kim M. Howell, Isabel S. Isherwood, Charles A. M. Msuya, et al. 2005. “NOTES ON THE ECOLOGY AND STATUS OF SOME FOREST MAMMALS IN FOUR EASTERN ARC MOUNTAINS, TANZANIA.” Journal of East African Natural History 94 (1): 175–89. https://doi.org/10.2982/0012-8317(2005)94%5B175:NOTEAS%5D2.0.CO;2.

Hoeck, Hendrik. n.d. “Hyraxes, Order Hyracoidea. Biological Synopsis.” IUCN/SSC Afroteria Specialist Group. http://www.afrotheria.net/Hyracoidea.html (accessed 16.2.2020)

IUCN. 2013. “Dendrohyrax Arboreus: Butynski, T., Hoeck, H. & de Jong, Y.A.: The IUCN Red List of Threatened Species 2015: E.T6409A21282806.” International Union for Conservation of Nature. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T6409A21282806.en.

IUCN. 2014. “Dendrohyrax Validus: Hoeck, H., Rovero, F., Cordeiro, N., Butynski, T., Perkin, A. & Jones, T.: The IUCN Red List of Threatened Species 2015: E.T136599A21288090.” International Union for Conservation of Nature. https://doi.org/10.2305/IUCN.UK.2015-2.RLTS.T136599A21288090.en.

Kingdon, Jonathan, ed. 2013. Mammals of Africa. Vol. 1: Introductory Chapters and Afrotheria. London: Bloomsbury.

Maloiy, G. M. O., and R. M. Eley. 1992. The Hyrax. Nairobi, Kenya: R.M. Eley. THE HYRAX BOOK Lataa

Roberts, Diana. 2001. “GEOGRAPHIC VARIATION IN THE LOUDCALLS OF TREE HYRAX – DENDROHYRAX VALIDUS (TRUE 1890) – IN THE EASTERN ARC MOUNTAINS, EAST AFRICA: TAXONOMIC AND CONSERVATION IMPLICATIONS.” UNIVERSITY OF READING.

Topp-Jørgensen, Elmer, Andrew R Marshall, Henry Brink, and Ulrik Pedersen. 2008. “Quantifying the Response of Tree Hyraxes (Dendrohyrax Validus) to Human Disturbance in the Udzungwa Mountains, Tanzania.” Tropical Conservational Science 2008 (1 (1):63-74). https://tropicalconservationscience.mongabay.com/content/v1/08-03-03-Yopp-Jorgensen.htm.