Merriam's Kangaroo Rat - Behavior

Behavior

Merriam's kangaroo rats live individually within a maze of underground burrows. Males and females each establish individual territories. They defend their territories against other male and female merriami, primarily to protect often scarce food resources. It is typical that they locate multiple entrances to their burrow complex at the base of shrubs near the middle of their territory. This allows more opportunities for them to escape from predators.

Most Kangaroo rats are exclusively nocturnal. Even so, they tend to avoid being outside their burrows when the moon is full. The greater the amounts of moonlight the less time they spend collecting food, defending their territory, or searching for mates. When the amount of moonlight is great they retreat underground in order to avoid predation. In some areas, above ground activity is limited to two hours or less. During the day, they remain in their cool burrows. They often seal entranceways to their burrows with soil to prevent exposure to heat. When they are active above ground they move about within their territory and attempt to fill their cheek pouches with seeds and plant material. When their cheek pouches are full they retreat to their burrows where they disgorge the seeds they have collected. Some of the food is eaten immediately while the remainder is stored (often building a seed cache of considerable size) in several chambers within the burrow system.

Kangaroo rats lose water mainly by evaporation during gas exchange, and so have developed a behavioural adaptation to prevent this loss. As they spend a lot of time within their burrows to escape the heat of the day, the burrows become much more humid than the air outside (due to evaporative loss). When collecting seeds, they store them in the burrows rather than eating them straight away. This causes the moisture in the air to be absorbed by the seeds, and the kangaroo rat regains the water it has previously lost when it then consumes them.