, Santa Rita Mountains, southeastern Arizona Pallid bats are typically found in arid or semi-arid habitats, often in mountainous or rocky areas near water. They are also found over open, sparsely vegetated grasslands. During the day time, pallid bats typically roost in cracks and crevices, which may include tile roofs, exfoliating bark of trees, or rocky outcrops. During the night, this species will often use a night roost that is closer to their foraging grounds than their day roost. A night roost is usually less protected than a day roost; open porches may be used as night roosts by this species. In the winter time, this species may dip into shallow bouts of
torpor, often in buildings, caves, or cracks in rocks. Although pallid bats are primarily insectivores, they exhibit some flexibility in their diet when seasonally feeding on Mexican columnar cacti (particularly
cardón cactus) nectar in spring, and even cactus fruit in summer. Pallid bats are also more effective pollinators than some of the nectarivorous bats with whom they compete for cacti. Like many other bat species, pallid bats are
heterothermic, meaning they can be either
poikilothermic or
homoeothermic ( cold blooded and warm blooded) depending on the time of year. They have the ability to control their body temperature and equilibrate it with the environment during winter
hibernation and whenever they rest. Pallid bat size varies greatly depending on their habitat. Bats in areas of low
primary productivity, such as the desert, tend to be smaller due to less availability of resources. The bats that reside in areas with more primary productivity, such as coastal regions tend to be on the larger side. Larger pallid bats also have craniums that allow them to eat larger, harder prey more easily. == Behavior and natural history ==