To calculate the population density, you use the formula:
\[ \text{Population Density} = \frac{\text{Number of Individuals}}{\text{Area}} \]
In this case, you have:
- Number of Individuals = 16 giraffes
- Area = 1 square kilometer
Now, substitute the values into the formula:
\[ \text{Population Density} = \frac{16 \text{ giraffes}}{1 \text{ km}^2} = 16 \text{ giraffes/km}^2 \]
So, the population density is 16 giraffes per square kilometer.