“Citizen scientists” called on to help count Grevy’s zebras

Registrations for the Great Grevy's Rally are now open.
Registrations for the Great Grevy’s Rally are now open. In the late 1970s there were 15,000 Grevy’s zebra. Today fewer than 2500 remain in the wild.

If you’re in Kenya at the end of the month, there’s a chance to take part in a unique census of the endangered Grevy’s zebra.

Those taking part in the Great Grevy’s Rally over the weekend of January 30-31 are asked to photograph every Grevy’s zebra they see, and sophisticated stripe recognition software will be used to analyse the number of sighted and re-sighted individuals over the two days.

It is the first ever national census of Grevy’s zebra, and it was conceived by members of Kenya’s Grevy’s Zebra Technical Committee as a means to count the endangered population.

Grevy’s Zebra Trust, Mpala Research Centre, Lewa Wildlife Conservancy, Marwell Wildlife and Northern Rangelands Trust’s community conservancies constantly monitor Grevy’s zebra populations and demographics across northern Kenya. But in order to accurately estimate the population, a thorough ground census is needed.

The methodology used to count the zebras will also provide insights on the age and sex structure of the Grevy’s zebra population in each area to assess whether or not the overall Grevy’s zebra population is stable, growing or decreasing.

The population estimate and distribution determined by the GGR will inform future conservation and management initiatives.

Each Grevy’s zebra has a unique stripe pattern, which allows each individual to be identified. The photographs will then be processed by the Image Based Ecological Information System (IBEIS), which will identify the individual and its age and sex, and will record the observational time and location. The IBEIS results will estimate the size of the Grevy’s zebra population throughout Kenya.

Over the weekend of the Great Grevy’s Rally, scientists, landowners and conservancy managers will be joined by members of the public in driving through designated areas and photographing  the right side of each individual Grevy’s zebra observed with a provided GPS enabled digital camera.

In the late 1970s there were 15,000 Grevy’s zebra. Today fewer than 2500 remain in the wild. The Grevy’s zebra has suffered one of the most drastic population declines of any African mammal, because of climate change, habitat loss and competition with livestock.

“Now is our chance to come together to save this rare Kenyan heritage,” said Sheila Funnell, research manager of the Grevy’s Zebra Trust.

Each photograph will contribute to the current population age and sex structures. The age and sex structure of a population indicates its potential to grow. For example, if the total number of juveniles and foals account for 25% of the total population, then the population is on the rise. As for sex structure, if there are three females for every one male, then there is high potential reproduction and overall population growth. The population’s distribution and age and sex structures will indicate areas of high and low growth potential.

The Great Grevy’s Rally

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