Olorgesailie Pre-Historic Site: Archaeology, Paleontology, and Birdwatching

The hot dry air engulfed us upon disembarking from the car. I could hear an African mourning dove call in the distant. One of the guides directed us to the entrance to register and make payments. The reception was cool and provided the much needed shade from the scorching sun. Upon payment, our assigned guide narrated more on the murals on the wall. She explained that the site was once a lake basin and due to faulting; the lake level rose and fell several times causing changes to the lake basin. Eventually the ancient lake and stream beds were elevated and erosion cut deep to expose a portion of an elephant site which was then excavated and further elaborated that numerous handaxes are also found in this area.

Olorgesailie prehistoric site is famed for vast accumulations of Stone Age tools known as handaxes. Handaxes were made by early humans who lived here between 500,000 and 1 million years ago. The handaxes were a basic part of early human technology and was used in Africa, Asia and Europe for over 1 million years – starting around 1.5 million years ago.

One of the signage read, “Olorgesailie is one of the best known hand axes sites in Africa. Besides handaxes, this site also has evidence of fossil animals and ancient habitats where early humans lived. First discovered in 1919, prehistoric artifacts have been excavated at Olorgesailie during the 1940s, 1960s and again since 1986 with the cooperation of the local people and the Government of Kenya.”

A red-yellow barbet near the reception area seemed to guide us along a footpath before branching off into a bush as we set off on our pre-historic walking tour; armed with a wide-brimmed hat and a bottle of water. Our guide explained that the Olorgesailie area experienced many volcanic eruptions in the past. Many volcanic layers were deposited at Olorgesailie and the oldest volcanic layers are over 1 million years old. The youngest are less than 50,000 years old. The ages of many layers in between are also known.

As we approached the next excavation site, a von der decken’s hornbill flew off one of the nearby bushes as we entered the tin-roof Elephant Humerus site that is about 992, 000 years old. Remains of the extinct (Elephas Recki) can be viewed here and its remains indicate that it is more closely related to the Indian Elephant that the modern African species. We later walked to the next site, the Hippo Banda Site that is about 992,000 years old; here stone cutting tools and scattered bones of a single hippopotamus can be seen.

The Mid Site is about 780,000 years old and in the original excavation; more than half of all artifacts found here were handaxes. These are now at the national museum. The small stone flakes are left as exhibit at the site. Many of the handaxes were found oriented northeast – southwest indicating the direction of water flow in the old stream. As we left, a flock of blue-naped mousebirds flew above us as we walked along to the designated footpath. According to our guide, studies show that Olorgesailie is the most precisely dated site in Africa that preserves human stone tools, animal bones and environmental clues of the past 1 million years.

On the raised semi-circular catwalk platform was a slate-coloured boubou that flew off immediately upon realizing our presence. We could see Mount Olorgesailie in the background and our guide explained that the core of the volcano was already extinct by the time humans occupied this region. The catwalk has a concentration of stone handaxes found in 1942 by Dr. Mary Leakey. These handaxes were exposed by natural erosion and led to the initiated prehistoric research at Olorgesailie that unraveled stone tools and fossils bones.

After a short walk, we came about site DE/89 (East side) that is about 780,000 years old. Here, concentrations of stone tools and animal bones occur in three main layers. About 500 handaxes, 7,500 other stone artifacts and fossils of over 100 large baboons were associated with sands in this area. Flowing water would have altered the original distribution of the remains. The excavations show that this was a popular area for early humans to leave handaxes and it has even been suggested that the fragmented bones were food remains of the hominid toolmakers.

We found a flock of grey-capped social weavers busy foraging on the ground under a bush. The tour offered us views of picturesque landscapes, rolling mid-sized grass at offers the perfect contrast against the blue sky. Our guide narrated that site DE/89 (West side) is about 780,000 years old and comprises of three layers of stone tools in the of excavation. She elaborated that over 100 stone artifacts and fossils of zebras, pigs, hippos, antelopes and a single baboon tooth were uncovered in this excavation; however, all but those seen here are conserved in the National Museum in Nairobi.

Of the more recent excavations it the trial trench that is about 662,000 years old. It was dug in 1943 and this excavation site shows stone tools and animal bones in volcanic sands, gravels and pieces of volcanic pumice in this sediment layer. Handaxes, cleavers and other artifacts were also found in this layer and indicate that early hominids lived in this area. Here, the remains are found on the floor of an old stream. The eroded hollows contained large stone handaxes, flakes, cores and a cluster of rounded stones. Fossils found here included a partial hippo carcass and pig tusks. Coarse sandy sediments and rounded edges of some stone tools suggest that flowing water disturbed the original positions of these remains.

Other interesting birds we spotted during our walk included: African-grey Hornbill; a Taita fiscal perched on a bush was a lifer to most of us, White-bellied canary, Chestnut weaver, Scarlet-chested sunbird, Common drongo, Laughing dove, Vitelline  masked weaver, Common bulbul,  and a female Chestnut sparrow.

After the walk to took our refreshments at the open-dining area and adjacent was a huge tank that offered effortless birdwatching opportunities from the sun under the comfort of our chairs and shade. Birds seemed to take turns in taking bath in a shallow puddle of water under the tap that included; Black-necked weaver, a Cut-throat finch perched on a bush seemed to wait the longest and underneath was a White-browed scrub robin, an African firefinch, and Purple grenadier were foraging on the wet ground.

The Olorgesailie Pre-historic is a haven for archaeology, geology and paleontology lovers who are keen on learning more on the diverse types of sediments, history and livelihood of the people living in that area. Contact us via tours@beadsafariscollection.co.ke to book for a day trip or overnight stay at the site.