The Great Grevy's Rally Returns

By Zoe Sims

Above, a Grevy's Zebra and Reticulated Giraffe are caught on camera together during the 2018 GGR.


How many Grevy’s Zebra remain in Kenya? Where do they live? And what is their population structure? In January 2018, hundreds of citizen scientists came together to help researchers answer exactly these questions.

Armed with cameras and simple instructions, participants in the second-ever Great Grevy’s Rally (GGR) took to the bush to photograph endangered Grevy’s Zebras and threatened Reticulated Giraffes across northern Kenya. Photos amassed from the two-day event are allowing scientists to construct an accurate estimate the total populations of the two species nationwide.

The 2018 GGR was the largest citizen science effort ever undertaken in Kenya, bringing together conservancy members, county officials, the Kenya Wildlife Service, and citizen scientists from across Kenya and around the world.


Above left, during a break in the search for wildlife, some of Mpala's youngest citizen scientists complete an exercise about Grevy's Zebra biology and conservation. 

The project grew out of the Mpala-based Grevy’s Zebra Project, which has studied the population, dynamics, and behavior of the endangered species for the last decade. The Grevy’s Project research contributed to the development of Wildbook, a technology that can “read” the unique stripes of a zebra or the patches of a giraffe, just like fingerprints, to distinguish between individuals. This technology empowers anyone with a camera to contribute to understanding the species and its conservation. 

-  Learn more: Watch a video about the Wildbook technology and how it is used in the GGR.  - 


Below, participants of all stripes roam Mpala as part of the Rally: at left, a group of visiting students from the Turkana Basin Institute's Field School program search near the Mpala airstrip; at right, scientists capture a Grevy's in northern Mpala.

In 2018, Mpala partnered with the GGR team in support of the event and, in collaboration with Wildlife Direct, hosted young students from across the country, as near as the Mpala Primary School and as far as Nairobi. The students traversed the Mpala landscape photographing Grevy’s Zebras and Reticulated Giraffes, and learning about the species, their habitats, and their conservation along the way.

In total, the Rally included over 170 teams of citizen scientists – from families from Nairobi, to Kenya Wildlife Service rangers patrolling the far northern reaches of the zebras' range, to Mpala staff. Each team traveled to a portion of the zebras' range, across the Laikipia, Samburu, Isiolo, Marsabit, and Meru Counties, and used GPS-enabled cameras to photograph every Grevy’s Zebra and Reticulated Giraffe they encountered.

Together, the teams captured over 55,000 photographs! These photos are now being sorted and analyzed to identify every unique individual spotted in the Rally. From this information, scientists will estimate the total size of the population by comparing the individuals photographed on the first versus the second day of the Rally, a photo-based adaptation of the common “sight-resight” (or “capture-recapture”) survey technique.

Above, a group of Grevy's Zebras visit a watering hole near Mukenya Rock on Mpala. 

The preliminary results of the Rally will be released in early June 2018, and the official results will first be announced at the Great Grevy's Ball, to be held on June 23, 2018, at the Mt. Kenya Safari Club in Nanyuki. For more information or to sign up for the Ball, visit, or contact the event organizers at or 0717-574-697.

The final results of the Rally will provide key insights into the species’ current status, population structure, and distribution after the past two years of drought and conflict in the region. The Rally’s ultimate aim is that this information will inform the species’ conservation, while, at the same time, the experience of participating in the scientific process and interacting with the species in their natural habitats will empower and engage citizens and youth in the conservation of these unique and threatened species.


Asante sana - thank you - to the many local and global partners who made the 2018 GGR possible!