Obtaining reliable estimate for wildlife population sizes is highly desirable for management and conservation purposes but it is rarely a straightforward exercise… However sometimes, nature makes it a bit easier for us, as some species have pelage patterns that allow for identifying individuals. Such is the case for giraffes, zebras and leopards for instance, and based on pictures, one can count how many different individuals can be recognised.
We set out to do just that for our giraffe images collected from camera traps deployed for 16 consecutive days at waterholes in the height of the 2016 dry season. With just over 30 000 images of giraffes, it was a time-consuming activity, for which we used a clever piece of software named HotSpotter to help us in the recognition of the coat patterns.
So, how many giraffes did we have on Ongava in 2016? Well, we identified a total of 101 individuals, among which 41 adult males, 58 adult females and 2 juveniles of unknown sex. Assuming that we have seen all the individuals (which is unlikely to be the case- for instance in some pictures it was not possible to identify the individual), that would give a density of 0.3 giraffes per km2 on Ongava.