Before I tell you the answer, you should know that there are many factors that affect the Average lifespan of a Gerbil. The most important ones are: Breed. There are about 110 different breeds of gerbil, with each having a slightly different life expectancy. Wild vs captivity. In general, pet gerbils live longer than wild gerbils. Quality of food and water. Healthy nutritious food, and access to clean drinking water, are important factors for a long life. Accidents and diseases. Accidents, like falling from the top of the cage or being taken by a predator in the wild, are ever-present