Macrotus californicusCalifornia leaf-nosed bat

Geographic Range

The California leaf-nosed bat, the most northern member of the Phyllostomidae, lives in Northen Mexico, Baja California, southern Arizona, southern California and southern Nevada (Constantine 1998).


This species can be found in the caves and abandoned mines in deserts of South West North America. In the winter, they choose roosts that are geothermically heated (Tuttle 1998).

Physical Description

The Macrotus californicus has short broad wings and huge ears and eyes (Tuttle 1998). It's skull has no post orbital processes and a complete premaxillae.

  • Average mass
    8-17 g
  • Average mass
    11.7 g
    0.41 oz
  • Average wingspan
    33-35 cm
  • Average basal metabolic rate
    0.082 W


During the summer, most males form separate colonies close to female groups of around 100-500 members. However, a handful of dominant males stay within the female colony and have harem groups consisting of 5-25 females and young (Tuttle 1998).

Mating takes place in the fall. For the first several months of gestation, the embryo develops extremely slowly. Development speeds up in the spring, and young are born in June. (Tuttle 1998).

  • Breeding season
    Mating takes place in the fall, birth in the spring
  • Range number of offspring
    1 to 2
  • Average number of offspring
  • Average number of offspring
  • Average gestation period
    8 months
  • Average gestation period
    270 days
  • Average weaning age
    1 months
  • Average age at sexual or reproductive maturity (female)
    6 months
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    120 days
  • Average age at sexual or reproductive maturity (male)
    12 months

Infants are born with open eyes and ears and a full coat of fur. Infants nurse for one month. While females become sexually mature their first fall, males take a full year to reach sexual maturity (Harris 1999).



These bats have year long activity and do not migrate or hibernate. Members of this species are nocturnal, generally emerging 90-120 minutes after sunset during the summer, returning to their roost approximately one hour before sunrise (Harris 1999).

Communication and Perception

Food Habits

M. californicus is an insectivore. It uses its unuusal hovering ability to capture insects from the ground instead of from the air. It also uses its keen sense of vision over echolocation whenever light is adequate (Bell 1986). They feed up to 1.3km from their roost (Harris 1999).

Foods eaten include: crickets, moths, beetles, and grasshoppers, cicadas and caterpillars.

  • Animal Foods
  • insects

Ecosystem Roles

M. californicus plays an important role in insect control.

Economic Importance for Humans: Positive

M. californicus, an insectivorous bat, helps to control pest populations.

  • Positive Impacts
  • controls pest population

Conservation Status

Populations of this species are definitely decreasing. Human disturbances in caves and the reestablishment of mines is driving these animals out of their homes.

Temperate North American bats are now threatened by a fungal disease called “white-nose syndrome.” This disease has devastated eastern North American bat populations at hibernation sites since 2007. The fungus, Geomyces destructans, grows best in cold, humid conditions that are typical of many bat hibernacula. The fungus grows on, and in some cases invades, the bodies of hibernating bats and seems to result in disturbance from hibernation, causing a debilitating loss of important metabolic resources and mass deaths. Mortality rates at some hibernation sites have been as high as 90%. While there are currently no reports of Macrotus californicus mortalities as a result of white-nose syndrome, the disease continues to expand its range in North America. (Cryan, 2010; National Park Service, Wildlife Health Center, 2010)


Sarah Abbott (author), University of Michigan-Ann Arbor, Ondrej Podlaha (editor), University of Michigan-Ann Arbor.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


an animal that mainly eats meat


Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.


uses smells or other chemicals to communicate


used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females


An animal that eats mainly insects or spiders.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night


having more than one female as a mate at one time

seasonal breeding

breeding is confined to a particular season


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


uses touch to communicate


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.


Bell, Gary P., February 1986. Visual Acuity Sensitivity and Binocularity in a Gleaning Insectivouous Bat Macrotus californicus Chiroptera Phyllostomidae. Animal Behaviour, 34: 409-414.

Constantine, D. August 1998. Range Extensions of Ten Species of Bats in California. Bulletin Southern California Academy of Sciences, 97: 49-75.

Cryan, P. 2010. "White-nose syndrome threatens the survival of hibernating bats in North America" (On-line). U.S. Geological Survey, Fort Collins Science Center. Accessed September 16, 2010 at

Harris, J. 1999. "California Leaf-Nosed Bat" (On-line). Accessed October 11,2001 at

National Park Service, Wildlife Health Center, 2010. "White-nose syndrome" (On-line). National Park Service, Wildlife Health. Accessed September 16, 2010 at

Tuttle, Merlin, Winter 1998. "The California Leaf-nosed Bat, Sophisticated Desert Survivor" (On-line). Accessed October 11, 2001 at