Animal Diversity Web

Geographic Range

The lesser bulldog bat is a neotropical mammal. Its range extends from southern Mexico, to eastern Brazil then south into northern Argentina and Peru (Wilson and Reeder 1993).

• Biogeographic Regions
• neotropical
  • native

Habitat

This species is found in a variety of vegetation types throughout its range, but it is always located near streams, bodies of water or other moist places. Bulldog bats typically roost in hollow trees, foliage and man-made structures. Members of this species have been found in association with the mastiff bat Molossus molossus; the roost can easily be identified by the musky odor of the lesser bulldog bat (Nowack 1994).

• Habitat Regions
• tropical

Physical Description

Forearm length: 54-70 mm.

The upper parts of N. albiventris are grayish brown to yellowish in color or bright red. Typically color is sexually dimorphic, with males being bright red and females dull brown and drab. Individuals have a paler middorsal line and paler underparts. The nose of these bats is very pointy, but has no nose leaf or other projections. The tail extends about half of the length of the well-developed uropatagium. The relatively short hind limbs are almost completely free from the wing membrane. The wings of N. albiventris are long and narrow in comparison to other families within Microchiroptera. Noctilio albiventris can be distinguished from its close relative N. leporinus by its smaller size, smaller hind limbs and smaller claws on the hind feet (Nowak 1994).

• Other Physical Features
• endothermic
• bilateral symmetry

• Range mass

  18 to 44 g

  0.63 to 1.55 oz

• Range length

  57 to 85 mm

  2.24 to 3.35 in

Reproduction

Little else is known about the reproductive strategy of N. albiventris, however the mating system of its close relative N. leporinus is documented. Noctilio leporinus live in single-male/multiple-female groups in year-round harems with stable female composition (Walker 1964).

The reproductive behavior of N. albiventris is highly synchronous. These bats have a well defined breeding season with mating occurring in late November or December and birth occurring in late April or early May (Hooper and Brown 1968). Lactation continues for 3 months, and then juveniles are weaned. Only 1 young is born per year (Walker 1964). Young probably reach sexual maturity after their first year of life. At birth lesser bulldog bats have eyes that are barely open, ears that are incompletely developed and a distinct lack of hair. The baby bats are relatively slow to acquire fur and to attain the proportions of an adult. Most are able to fly 35 to 44 days after birth. Although echolocation is an important tool utilized in flight by adult bats, baby bats cannot fly and therefore do not emit echolocation signals. Newborn bats do not even show a behavioral or physiological response to sound until they are a week old. Vocal, auditory and motor systems appear to develop at a similar rate, resulting in a juvenile bat that is able to forage 3 to 6 weeks after birth (Brown et al. 1983).

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• viviparous

• Breeding season

  Mating occurs from November to December and births occur from April to May.

• Average number of offspring

  1

• Range gestation period

  4 to 5 weeks

• Average weaning age

  3 months

• Average age at sexual or reproductive maturity (female)

  1 years

• Average age at sexual or reproductive maturity (male)

  1 years

This species is relatively altricial. Young are born helpless and are nursed and cared for by their mother until they reach independence.

• Parental Investment
• altricial
• female parental care

Lifespan/Longevity

Noctilio albiventris individuals can live 10-12 years in the wild (Brown et al. 1983).

Behavior

Noctilio albiventris have been noted foraging with 8-15 conspecifics. Studies of the activity pattern of this species show a peak in activity immediately after sundown (Hooper and Brown 1968). This social and nocturnal mammal has developed an intricate communication system that is discussed below.

• Key Behaviors
• nocturnal
• motile
• social

Communication and Perception

• Perception Channels
• tactile
• chemical

Food Habits

Noctilio albiventris individuals use echolocation to locate insects near the surface of the water. Although the other member of this genus, N. leporinus, is piscivorous, N. albiventris is primarily insectivorous. The feeding behavior of N. albiventris is flexible. Aerial capture is used as the primary foraging strategy, but if an insect falls to the surface of the water, N. albiventris is able to quickly change its foraging strategy to capture the insect by scooping it up from the surface of the water (pointed dip) or by raking the surface of the water with its hind claws (directed random rake) (Lewis-Oritt et al. 2001). This behavioral plasticity is thought to be a precursor to the evolution of piscivorous feeding behavior in N. leporinus (Kalko et al. 1998). In laboratory studies, N. albiventris has been trained to take floating fish from the surface of the water (Suthers and Fattu 1973) and researchers have identified fish scales in N. albiventris guano. There have been limited observations of these bats taking fish in the wild (Galileu Coelho, pers. comm.). Based on studies of the stomach contents of N. albiventris, most of the diet is derived from insects (Nowak 1994).

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• fish
• insects

Predation

Predators of bats are typically either terrestrial predators that take young from roosts, such as snakes, raccoons, ringtail cats, or small cats, or avian predators that take adults on the wing, such as falcons, hawks, or owls.

Ecosystem Roles

Lesser bulldog bats are important predators of insects in the ecosystems in which they live.

Economic Importance for Humans: Positive

Direct economic impact of this species has not been determined. However, these bats serve an important pest management function throughout their range and can produce commercially valuable guano.

• Positive Impacts
• produces fertilizer
• controls pest population

Conservation Status

This species is currently not listed.

• IUCN Red List

  Least Concern
  More information

Contributors

Barbara Lundrigan (author), Michigan State University, Amy Kamarainen (author), Michigan State University.

References

Brown, P., T. Brown, A. Grinnell. 1983. Echolocation, development, and vocal communication in the lesser bulldog bat, *Noctilio albiventris*. Behavioral Ecology and Sociobiology, 13(4): 287-298.

Crichton, E., P. Krutzsch. 2000. Reproductive Biology of Bats. Academic Press.

Hooper, E., J. Brown. 1968. Foraging and Feeding in two sympatric species of neotropical bats, genus *Noctilio*. Journal of Mammalogy, 49: 310-312.

Kalko, E., H. Schnitzler, I. Kaipf, A. Grinnell. 1998. Echolocation and foraging behavior of the lesser bulldog bat, *Noctilio albiventris*: preadaptations for piscivory?. Behavioral Ecology and Sociobiology, 42(5): 305-319.

Lewis-Oritt, N., R. Van Den Bussche, R. Baker. 2001. Molecular evidence for piscivory in *Noctilio* (Chiroptera: Noctilionidae). Journal of Mammalogy, 82(3): 749-759.

Nowack, R. 1994. Bats of the World. The Johns Hopkins University Press.

Suthers, R., J. Fattu. 1973. Fishing behavior and accoustic orientation by the bat (*Noctilio labialis*). Animal Behaviour, 21: 61-66.

Wilson, D., D. Reeder. 1993. Mammal Species of the World: Second Edition. Washington, D.C.: Smithsonian Institution Press.