The Mountain Zebra Project aims to understand what causes changes in Hartmann’s mountain zebra population size in order to provide information needed for their conservation. This sub-species is classified as Vulnerable under the IUCN Red List and is specially protected in Namibia. Historical records show that they are vulnerable to extreme drought, particularly when fencing restricts their ability to find remaining patches of grazing. In this project I use two zebra characteristics to monitor their populations: 1) each mountain zebra can be recognised using fingerprint-like variation in stripe patterns and 2) they need to visit waterholes to drink. Using motion-sensitive camera traps at waterholes, I have photographed and identified large numbers of zebra in some key populations. For example, over 3,000 individuals are now known in the mountainous part of the Namib-Naukluft National Park. When I identify animals under two years old, I estimate their year of birth and then follow their progress throughout the rest of their lives using networks of camera traps. Individuals that are not seen for several years are assumed dead. Births and deaths in the population are then related to factors in their environment such as rainfall and consequent grass growth, and zebra population density. Rainfall is the main predictor of zebra birth and death rates in Gondwana Canyon Park in southern Namibia – in good rainfall years, there are more births and fewer deaths, and vice versa in years of drought.