In a year’s study of the giraffe population of the Arusha National Park we identified 462 individuals. The cumulative first sightings of individuals were fitted to a logistic model that gave an estimated total population of 471. Immatures accounted for only 24% of the population. Twenty-two calves were born during the period of study. The giraffe of the Park are divided into ‘North’ (more precisely northeastern) and ‘South’ (southeastern) subpopulations, and although there is no barrier between them, only 3%