Another endangered species that visitors hope to see is the San Joaquin kit fox. This small, dust-colored canid is one of the most endangered animals in California. The species was fairly common up until the 1930s when farming and human development took over the valley. Now there are fewer than 7,000 left, and spotting them is a matter of luck. Today, not only is the San Joaquin kit fox faced with human encroachment — which causes displacement in habitat, increased difficulty in finding food and an increase in rodent poisons, which also kill the foxes — but also climate change. The species' population rises and falls along with rainfall, and the increased severity of droughts and changes in weather patterns caused by climate change are serious problems.