California Leaf-nosed Bat, Macrotus californicus

California Leaf-nosed Bat, Macrotus californicus

The California leaf-nosed bat (Macrotus californicus) is common to the United States and Mexico. The range of this leafed nose bat includes New Mexico, Nevada, Arizona, and in the scrub habitats located in the Mohave and Sonoran deserts in California. They can also be found in western Mexico.

The California leaf-nosed bat is brown in color. It can weigh up to .7 ounces and has a wing span of over eleven inches. The long ears can be up to .9 inches and it has a body length of up to 2.4 inches. The leaf-nosed bat has a fleshy, triangular growth of skin just above its nose.  Because of its shorter wingspan, this bat is adept at maneuvering through the air, but it is not suited for migrating. It does not hibernate during the winter either. The breeding method of this bat is similar to other bats. It will mate in the fall, storing the sperm until around March, and will not give birth until May or June. It is common for the California leaf-nosed bats to have twin pups.

Preferring to roost in caves, grottos, or tunnels (including abandoned mineshafts), the California leaf-nosed bat will live relatively close to an opening. They can roost anywhere from thirty to eighty feet from the entrance, and possibly even twenty feet. In order for the home to be suitable, there must be amble coverage from the weather, and plenty of space to fly and land. After landing on a slanting portion of the ceiling, the bat will hang upside down by one foot. The other foots is typically used for grooming or scratching. This activity produces an interesting swaying movement. Unfortunately, humans can be a danger to the leafed-nose bat habitats. During the summer months, when bats are raising young, humans can interrupt the natural process. If the bats are living in mineshafts, the restoration or re-working of the mines causes a complete loss of habitat. Luckily, the conservation status of this bat is of least concern.

The flight patterns of the California leaf-nosed bats are slightly different from other bats. Because of the short wingspan, this bat cannot fly long distances, but is extremely maneuverable. It is quieter than most other bats, and it flies at slower speeds while foraging. However, it is capable of more rapid flight. Upon landing, this bat will fly around eight inches below the ceiling of a cave and with a strong downward stroke of its wings, will push itself toward the ceiling. This forceful motion causes the bat to turn upside down, enabling it to latch onto its roost. The bat can take off again using two methods; it may swoop in a slightly curved manner down from the roost or it may fly directly off the roost. Bats differ from birds in the way they fly because, it is thought, they have different feeding methods. Bats will forage, therefore there is not a need for lifting food off the ground and they will fly nearly continuously to feed. Birds, on the other hand, need better lifting strength to hunt for food, and land more often than bats do.

In order for the bat to take off, it uses a number of membranes along its wings and body. The membrane known as the propatagium is the area in front of the bats arm, and these help shape each wing. The membrane that attaches the forelimb and hind limb together, called the plagiopatagium , is used when the bat flies or glides. This has a greater surface area than the membrane between the digits on the wings, called the chiropatagium . The under sides of the wings receive more air pressure when the bat takes off than the dorsal (or back) sides of the wings. This allows the bat to have an increased, curved “lift off” position.

This bat is capable of hovering for a short period, and when hunting for food, can hover three to four feet above the ground before descending to glean it. Gleaning is the process of picking food off a surface. This method is not common to birds, but is common in bats. After consuming a number of insects including moths, caterpillars, and beetles, the California leaf-nosed bat will return to its roost by sunrise.

Image Caption: The California Leaf-nosed Bat (Macrotus californicus) is a species of bat in the Phyllostomidae family. It is found in Mexico and the United States. Its natural habitat is hot deserts. It is threatened by habitat loss. Credit: United States National Park Service/Wikipedia