Ranging behaviours across ecological and anthropogenic disturbance gradients: a pan-African perspective of giraffe ( Giraffa spp . ) space use

One female giraffe ranged over nearly 4,000 square kilometres. Her estimated home range in Niger was at the expansive end of a continent-wide comparison; another female in Namibia used about 13 square kilometres. Such variation makes a single answer to how much space giraffes need misleading, even before roads, farms and fences reshape the available landscape.

Michael Brown, Julian Fennessy and colleagues combined GPS records for all four giraffe species. After excluding short records and animals without a stable home range, they analysed 148 giraffes at 22 study sites. Movement models accounted for the way successive locations depend on one another. The team then compared home ranges and daily travel with satellite measures of vegetation, human disturbance and their variation across space and time.

The estimated mean home range was 356 square kilometres, with daily movement averaging about 14 kilometres. Giraffes generally used less space in productive environments and more where resources were patchy or variable. Greater average human disturbance was associated with shorter movements and smaller ranges. These comparisons cannot show that every small range reflects confinement: plentiful food can also reduce travel. What matters is the landscape behind the number, including whether giraffes can still reach the resources they need.