Flora and Fauna of the Libyan Desert

The Libyan Desert is one of the aridest places on earth. In places decades may pass without any rain, and even in the highlands rainfall happens erratically, once every 5-10 years. At Uweinat, the last recorded rainfall was in September 1998. With such dryness, one would expect the desert to be totally lifeless. Yet there is a surprising abundance of lifeforms, sometimes in the most unexpected places.

In the northern part of the Great Sand Sea (50-100 km south of Siwa) one may find clusters of a sturdy shrub, Calligonum commosum, incredously growing out of the sand far above any permanent water table. How it survives is a mystery, it must capture the very meagre moisture from the air.

A colony of Calligonum commosum among dunes in the Great Sand Sea, about 70 kilometres south of Siwa (the southernmost vegetation noted among the dunes)

Further south plant life outside the oasis depressions is strictly limited to the bed of the larger wadis of the uplands and mountains. The dominant tree is Akacia raddiana, intermingled with fewer Akacia tortilis. (The former has a single thick trunk and erratic, generally rounded foliage, while the latter branches at ground level, and has a characteristic flat top).

"Forest" of Acacia raddiana in Karkur Talh		Karkur Talh, A. raddiana with tufts of Panicum turgidum in foreground		Grove of A. tortilis in Wadi Hamra
Large A. raddiana in Karkur Ibrahim		Fruit bearing A. raddiana in upper Karkur Talh		Thorns & leaves of A. raddiana in upper Wadi Abd el Melik

There is a further akacia species, the low bush-like Akacia ehrenbergiana growing at the sandy bottom of wadis. Probably the solitary group of bushes in a small depression near the airfield at Wadi Sora, and the low dome shaped akacias encountered in the main wadi of the "Unnamed Plateau" belong to this species.

Incredulously a few Acacia ehrenbergiana(?) manage to survive in a shallow depression near Wadi Sora		Appearing dry and dead from afar, the bushes actually bear fruit		An unidentified Acacia species grows in low dome shaped bushes in the main wadi of the "Unnamed Plateau"

Aside the akacias Maerua crassifolia lives in the upper reaches of the wadis of both Uweinat and the Gilf Kebir, and we have noted a single tamarisk Tamarix nilotica (?) growing near the spring at Jebel Arkenu.

Maerua crassifolia in a small side wadi of upper Wadi Abd el Melik		Leaves of Maerua crassifolia		Tamarix nilotica(?) near the spring at Arkenu
Flowering solitary Maerua crassifolia on the low plateau at the northern foot of the main mass of Jebel Uweinat, where no other vegetation was observed (March, 2004)

A bright green leaved Ficus species grows only in the upper reaches of Karkur Ibrahim at Jebel Uweinat, at an altitude between 800-1000 metres, in sheltered shady spots at the bottom of the deep and narrow wadi. The vegetation along wadi beds reaches up all the way to the summit, we have noted a solitary Maerua crassifolia at the head of a small wadi just under the peak at an altitude of 1800 metres. The highest elevation plant noted was a heavily grazed Fagonia thebaica just 70 metres under the summit.

Ficus teloukat(?) in Karkur Ibrahim at an altitude of 800 metres		Maerua crassifolia near the peak of Jebel Uweinat, at 1800 metres.		Fagonia thebaica on Jebel Uweinat, at 1850 metres the highest elevation plant noted.

The bottom of the wadis and karkurs support a number of grasses and shrubs. The grass Panicum turgidum grows in tufts, and covers much of the valley floors among the akacias at Uweinat. The shrub Zilla spinosa grows in dome like clusters, and can stay green for several years after rains. It is more common in the valleys in the Gilf Kebir. The "desert melon", Citrullus colocynthis grows in many lower lying areas of the wadis, usually at places where the rain runoffs end in shallow pools.

Bright green clusters of Zilla spinosain Wadi Hamra. Despite the lack of any rain, these have been green for the past two years.		Flowering Z. spinosa in upper Wadi Abd el Melik, where all other vegetation was dry		Thousands of dry Citrullus colocynthis in the lower course of Karkur Talh

Ripening Citrullus colocynthys in a small wadi near Wau Namus

In the low plateau to the north of Wadi Gubba in the Northern Gilf Kebir, we encountered a single example of a shrub, Cocculus pendulus that is common in the Sinai, Eastern Desert and Sahel, but it has been hitherto unreported from the hyperarid central Libyan Desert. It appears to be a very ancient plant, possibly a living fossil legacy of the earlier wetter periods, totally unexpected in the dry wadis that presently do not support any other trees or shrubs.

The vine like stems of Cocculus pendulus appear to be a pile of discarded ropes from a distance.		Unlike blooming specimens in wetter areas, foliage is limited to tiny, 1-2 cm sized leaves, only in spots that remain in the shade most of the day.

During the February 2003 expedition, we have encountered a colony of Salsola cyclophylla (? possibly S. tetragona) shrubs in another wadi of the same dry plateau north of Wadi Gubba. Salsola species have not been reported before in the central Libyan Desert. In the upper reaches of Karkur Talh at Jebel Uweinat, we found several examples of two species of blooming green shrubs, Pergularia tomentosa and Cleome droserifolia, perhaps the product of some very localised rains, that we have not seen before.

The branches Salsola cyclophylla support tiny bud-like green leaves and five petalled flowers encased in a protective cluster of dry leaves. A single known colony exists in a wadi that had no other vegetation except a few dry Zilla spinosa.		Pergularia tomentosa supports large ripe pods, 1-2 cm leaves and white blooming flowers, secretes a white sticky fluid from leaves and pods at the lightest touch.		Cleome droserifolia forms a circular low dome of waxy, hairy leaves among the rocks of the wadi bed. All other vegetation in the area except Acacia trees were dry and lifeless.

In October 2003, two shrub species were noted in a southern side wadi of karkur Ibrahim, both supporting fresh growth. They were subsequently confirmed as Fagonia thebaica, and Aerva persica, both common in the afro-arabian desert zone.

The fresh growth of Aerva persica has a silver colour and a velvety texture, with long narrow leaves.		Fagonia thebaica showing fresh growth of bright green stems with tiny fleshy leaves, and small five petalled pink flowers.

Fagonia thebaica may be encountered at totally unexpected places, where no other vegetation exists. A colony was noted in a sheltered sandy valley along the western cliffs of the Gilf, and is also abundant in the valleys of the Hassanein Plateau at Uweinat.

F. thebaica growing out of sand in a small sheltered valley at the foot of the western Gilf		F. thebaica on the Hassanein Plateau, Uweinat		The pretty purple flowers of Fagonia thebaica, Hassanein Plateau

During our exploration of the Hassanein Plateau in March 2004, two plant species were noted which have not been seen elsewhere. Bright green Heliotropium bacciferum with white flowers were seen abundantly. Another low shrub was noted at a two location. Initially it was unidentified, but in March 2005 they were flowering, and this allowed their positive identification as Ochradenus baccatus.

Heliotropium bacciferum seemed to be the dominant vegetation on the Hassanein Plateau together with Fagonia thebaica.

Three individuals of Ochradenus baccatus were growing in close proximity to a dry guelta on the Hassanein Plateau. All showed signs of grazing by waddan (Ammotragus lervia) in both 2004 and 2005. In March 2005 they were all flowering (as well as a further individual at another location).

After rains, the generally dry appearance of the wadis changes dramatically. Dormant seeds spring to life, and a few weeks after the rain bright green fresh growth and a multitude of flowers cover the bed of the watercourse. The pictures below were taken at Karkur Talh in November 1998, about two months after it rained.

Bright green fresh growth in the bed of Karkur Talh, strictly localised to the path of the meandering watercourse.		Much of the new growth was Tribulus mollis, with bright yellow flowers		Fresh growth C. colocynthis with flowers and a growing fruit at upper right

It took seven years of patience to see this amazing transformation again. In October 2007, Karkur Talh and several other valleys were bright green once again. This time we were better prepared, and the aftermath of the rains are fully documented. About half of the plant species noted at Uweinat are only observable after rain. In the interim arid spells, the seeds lie dormant in the sand.

Click on image for detailed account of the 2005 rains aftermath

The vegetation around permanent water sources can be dramatically different. Date palms (Phoenix dactylifera) grow near any permanent water source, while the banks of any open water surface are covered by a dense growth of reeds (Phragmites australis, Imperata cylindrica). Depressions near the water table are dotted with "tarfa" mounds, growth of tamarisk (Tamarix nilotica) on elevated sand hills supported by the plant's roots. The plant captures and anchors wind blown sand, and constantly grows above it, reaching heights of 10-15 metres.

Solitary Phoenix dactylifera beside well at Bir Terfawi. The well is just to the right of the palm, hidden by a dense growth of reeds.		Bir Terfawi. Clusters of P. dactylifera, tarfa mounds (Tamarix nilotica) in background. Foreground covered by dense clusters of Zilla spinosa		Dense growth of reeds around salt water lake at Wau Namus. Clusters of P. dactylifera and mounds of T. nilotica in background
Convulvulus prostratus on the wadi floor in Karkur Murr, near the spring		Phragmites australis growing from one of the rock pools at Ain Murr		Cluster of Phoenix dactylifera near the spring of Ain Murr

Animal life is the richest around vegetation, but amazingly one finds living creatures hundreds of kilometres from the closest plant and water. Even in the middle of the Sand Sea, the sand in the morning is covered by a multitude of tracks. In the daytime they are never seen, but at night the desert is alive.

Tracks on a dune at dawn at the edge of the Great Sand Sea

Insects are the most abundant, coming in all colors, sizes and flavors. The most abundant are the large black desert ants, that densely inhabit the akacia groves of Karkur Talh and the Gilf valleys, and incredulously butterflies, that seem to appear at any spot with the slightest green vegetation. In Wadi Hamra we did find a large spider that tried to make home in one of our cardboard boxes left out for the night, and encountered a fine exapmple of the same species in Karkur Ibrahim.

A young male desert locust, Schistocerca gregaria, caught in the "Gap" in November 1998.		A desert mantid of the Eremiaphila species. These small carnivore insects blend into the sand, and can dash an an incredible speed		Another mantid, Eremiaphila brunneri (?), in the Great Sand Sea.
In November 1998, after the rains, the flowers in Karkur Talh were engulfed in a swarm of millions of Painted Lady (Vanessa cardui) butterflies		A Vanessa cardui on flowering Zilla spinosa at a mini oasis along the North-eastern Gilf Kebir		A moth on the flower of Zilla spinosa in Wadi Hamra
A beetle making it's way accross the sand in Karkur Talh		A desert ant, Cataglyphis fortis in Karkur Talh (about 1 cm life size)		A large spider, Sparassus dufouri in Wadi Hamra, about 10cm in diameter with legs
An adult female S. gregaria at Arkenu in October 2003. Many solitary adults were noted, also at Uweinat.		A Sparassus dufouri in Karkur Ibrahim, October 2003		A common cricket, Gryllus bimaculatus in Karkur Ibrahim, October 2003

Scorpions do exist, but I have only encountered them near oases, not in the deep desert. One was seen near dakhla Oasis, having crawled under a tent. Another beautiful yellow Leirus quinquestriatus was seen in the Great Sand Sea south of Siwa. Per unit it's venom is more potent than that of a Cobra, however the amount of poison is so small that a sting is very rarely fatal for adult humans.

Freshly molted Leirus quinquestriatus, the deadliest of all scorpion species.

Many lizards live near vegetation in the NE Gilf Kebir valleys. The underside of the large Zilla spinosa bushes are an especially favored home.

Lizard, Acanthodactylus scutellatus in Wadi Abd el Melik		A. scutellatus under a Zilla spinosa in Wadi Hamra		An Agama mutabilis in the main wadi of the "Unamed Plateau" north of Uweinat

Snakes are abundant, but mostly their tracks and moulted skins are seen only. Tracks are frequent in areas far from any vegetation, even in the Great Sand Sea. They hide well among the rocks, only the trained eyes of Salama, our bedouin driver spotted them in places where we only saw rocks.

Partially mummified snake under a rock in Wadi Sora		A mildly venomous sand snake, Psammophis schokari near Wadi Sora.		Tracks leading to nowhere...(*)		Snake tracks in the sand, Great Sand Sea
* In fact the tracks are coming from nowhere. Many thanks to Uwe Moldzryk for spotting this !

During October 2003 it was unseasonably hot, with daytime temperatures nearing 40. This time we saw more snakes, than during all previous trips combined, all of them sand snakes (Psammophis schokari).

There are few permanent bird inhabitants. The most common is the "Zarzur" or White Crowned Wheatear (Oenanthe leucopyga), which is common all accross the Sahara. White wagtails (Motacilla alba) are also relatively frequent. As many of the great bird migration routes pass over the Libyan Desert, there are a great number of visiting species, and one may find many mummified corpses - the ones that did not make it accross the grueling route.

A Zarzur, Oenanthe leucopyga at Karkur Talh		A White Wagtail, Motacilla alba at Wadi Sora		Mummified remains on the Selima Sand Sheet
Perfectly preserved mummified Golden Oriole, Oriolus oriolus near Wadi Sora		Zarzur or White Crowned Wheatear (O. leucopyga) at Karkur Talh		A male Common Redstart, Phoenicurus phoenicurus at Wadi Sora
Mummified duck in the Great Sand Sea		Remains of an eagle (?) near Jebel Bahari		Mummified yellow wagtail in the Great Sand Sea

The few mammals that manage to survive in the great aridity are scarce and nocturnal, thus usually only their tracks are seen. The most common are various species of gerbils (Gerbillus) and jerboas (Jaculus) whose little padded feet and long tails leave distinct tracks in the sand. I've sat by the tripod, flash charged and bait set, for many hours during several nights, and none showed. In the morning when I woke up, the area around the tent was full of their tracks... Finally in march 2004 I've managed to take a few photos of a couple of gerbils at Wadi Sora.

A Lesser Egyptian Gerbil, Gerbillus gerbillus at Wadi Sora

There are many foxes in the valleys, not the cute fennec, but Rüppel's sand fox (Vulpes rueppeli), that can make a huge rattle with the empty dishes left around the camp fire after meals. They tend to be quite tame, and happily nibble away at left-over food in the blaze of torches shined at them from only a few metres away. Rarely they even approach a quiet camp in daylight. The photos below were taken at Karkur Talh in October 2002, from a distance of about 10 metres.

Only two species of larger mammals live(d) in the Libyan Desert. Dorcas gazelle (Gazella dorcas) inhabit the wadis on the plain to the south of Uweinat, and also live in the Karkurs. They have been hunted close to extinction by Italians and later the Libyans, but happily quite large numbers have found refuge in Karkur Talh, where they can often be seen in the early morning. The even rarer waddan, or barbary sheep (Ammotragus lervia) was relatively abundant in the Gilf and at Uweinat. Unfortunately indiscriminate hunting (primarily by poachers from Libya) have decimated their numbers, and today only the mummified corpses littering the wadis indicate their former presence, live sightings are very few. There is a particularly well preserved waddan mummy in Karkur Talh, obediently posing for visitor's cameras year after year.

Dorcas gazelle, Gazella dorcas at Karkur Talh. Photo by Francis Duranthon 2002 April 30, 19:00h		Mummified waddan (barbary sheep), Ammotragus lervia at Karkur Talh		A waddan at Karkur Talh. Photo by Yves Larboulette 2001 March 24, 17:00h

On the southern borders, near the Wadi Howar region, the Addax antelope (Addax nasomaculatus), White oryx and Ostrich were once abundant, but it's doubtful whether any numbers still survive. In 1935 Mason even reported a family of lions living in the Wadi Howar, and Almásy had a rather frightening encounter with a cheetah in the same region. Almásy reported tracking an addax between Uweinat and the Gilf Kebir, and we have found ourselves a very old looking addax skeleton near Wadi Sora, proving once it's range included the central Libyan Desert.

Salama with the addax horn near Wadi Sora. The heavily weathered horn was the only protruding part of the covered skeleton.		Almásy also reported seeing a mummified addax north of this location, thus two specimens are known from the Gilf area.		Most of the skeleton was covered by hardened dust at the floor of the shelter. The bones were very brittle, by appearance over 100 years old.

Fleeing herds of Addax nasomaculatus near Wadi Howar, Sudan. Photographs by Count Zsigmond Szechényi taken during the 1935 spring hunting trip with Almásy. Since then the species became almost extinct in the area.

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