Abiotic, biotic and human influences are factors that can affect animal home ranges. We calculated home range sizes of adult giraffes in the Tarangire-Manyara region of northern Tanzania (N ¼ 132 giraffes with data collected over 6 years), and investigated correlations between home range sizes and environmental and anthropogenic factors (for a subset of N ¼ 71 giraffes). We used a 95% kernel utilization distribution to define home ranges and modelled home range size as a function of environmental and