There are three subspecies of dwarf dog-faced bats: Molossops temminckii sylvia, Molossops temminckii temminckii, and Molossops temminckii griseiventer.
The primary method of communication and perception in bats, including dwarf dog-faced bats, is echolocation , which allows bats to hunt and navigate without light. Bats emit a short, high frequency, ultrasonic pulse to help determine the direction, distance, and features of objects in their environment from biaural cues such as arrival time, amplitude, and spectrum of sonar reflections. Bats modify these pulses to change duration, repetition rate, and intensity of calls. Dwarf dog-faced bats have an unusual ability to manipulate their use of echolocation, modifying their pulse emissions to a high degree. The echolocation cycles of bats can be broken down to a few general types of pulses. The first is the search phase, which has a count of 1 pulse per wing beat, and the emission is occasionally broken. The second phase is the approach phase, where the pulse rate increases to 2 pulses per wing beat. This higher frequency allows for more precise information about prey and surrounding area and structures. The next phase is the buzz or terminal phase, which occurs just before the capture of prey and is marked by a short pulse with a high rate of repetition, approximately 14 to 28 pulses. After the buzz phase, there is generally a period of silence, which is thought to occur while bats consume their prey. Dwarf dog-faced bats also use scent marking as a form of communication in order to maintain recognition of their home colony.
Communication Channels: acoustic ; chemical
Other Communication Modes: scent marks
Perception Channels: tactile ; ultrasound ; echolocation ; chemical
Dwarf dog-faced bats are abundant and are listed as a species of "least concern" on the IUCN Red List.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Dwarf dog-faced bats are considered pests when they roost in buildings used by humans. A fungus Histoplasma capsulatum can also grow on bat guano when left unchecked, which can release toxic spores. When these spores are inhaled, humans can contract Histoplasmosis, a disease that primarily affects the lungs and can become fatal. Bats also have a notoriously bad reputation for being carriers of the disease rabies. Although the percentage of rabies contraction from bat bites is very low, the ensuing cost of medical treatments can be an economic burden on an individual level.
Negative Impacts: injures humans (bites or stings, causes disease in humans )
Dwarf dog-nosed bats control insect populations, including crop pests. The nitrogen-rich bat guano of the family Molossidae is also harvested commercially for use in fertilizer.
Positive Impacts: produces fertilizer; controls pest population
Dwarf dog-faced bats help control some insect populations. They are also hosts to a variety of parasitic organisms, such as members of the family Nycteribiidae, or flies that feed on the blood of bats, and members of the genus Ornithodoros, or neotropical ticks common in bats.
Commensal/Parasitic Species:
Dwarf dog-faced bats are insectivorous bats that forage in groups to exploit large patches of insects in locations that attract high densities of insects such as near rotten wood or near streetlights. Their diet primarily consists of small beetles in the order Coleoptera as well as swarms of termites, winged ants, and moths. One captured and photographed individual had pollen on its lips from a bat-pollinated flower Bauhinia rufa, which may suggest consumption of pollen. Indeed, other insectivorous bats are expected to expand their diet to include pollen. It is also possible, however, that this bat was foraging for insects that visit flowers.
Animal Foods: insects
Primary Diet: carnivore (Insectivore )
Occurring exclusively in the neotropical region of the world, Molossops temminckii, or dwarf dog-faced bats, can be found in nearly every country in South America. This New World bat ranges in the north from Colombia and Venezuela to Brazil and Argentina in the south.
Biogeographic Regions: neotropical (Native )
Dwarf dog-faced bats have a large variety of habitats spanning many diverse geographical regions. They are primarily found in Amazonian rainforest and semi-deciduous forests, often near the forest edge and among dispersed trees near savannah or grasslands. They can also be found in dry lowland environments. Dwarf dog-faced bats roost in a variety of places, including caves, rock crevices, tree cavities, underneath tree bark, in rotting logs, foliage, and even holes in the ground. They also commonly inhabitant man-made structures, finding their way into attics and open spaces above human living areas. They are frequently found in roofs made of overlapping palm logs. Dwarf dog-faced bats can be found at sea level near the Atlantic ocean to elevations of over 1000 m at the base of the Andes Mountains.
Range elevation: 0 to > 1000 m.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; rainforest ; scrub forest
Other Habitat Features: suburban ; agricultural ; caves
The lifespan of dwarf dog-faced bats is not known. In general, bats are estimated to live a maximum of 20 to 30 years in extreme cases and, in most species, average 4 to 5 years of life.
Dwarf dog-faced bats are free tailed bats in the family Molossidae, members of which have a bony tail that is lacking a tail sheath. The genus Molossops, or dog-faced bats, is so named for the protruding nature of the snout that is dog-like in appearance. Dwarf dog-faced bats are the smallest in their genus, and may also be the smallest bats in Paraguay with an average length of less than 33 mm. Their skulls are distinctly broad and dorsoventrally (back to front) flattened. They have small eyes, and their ears are not joined at the midline of the skull but rather are well-separated and usually short and erect. Their tragus is short and triangular, while their antitragus is square and broad. Dwarf dog-faced bats have smooth upper lips and a dental formula of - 1/1-2 I, 1-1 C, 1-2/2 P, 3/3 M = 26-30 teeth. Like other Microchiroptera, dwarf dog-faced bats have a relatively short wingspan of .222 m +/- .004 m in males and .221 m +/- .004 m in females. Despite their small size, they are well adapted for flight. A ring of cartilage slides along the vertebrae in the tail by muscle contractions, stretching and retracting the tail membrane, and provides greater maneuverability in flight. Dwarf dog-faced bats have relatively long pelage, with hairs that extend beyond the claws of the toes. The dorsal side varies in color from dark brown, with the base of individual hairs yellowish with black membranes, to sandy brown, with whitish base color and light membranes. Pelage on the ventral side is usually lighter in color. In arid environment, the general color of their pelage is also lighter. Dwarf dog-faced bats exhibit sexual dimorphism, with males about 5% larger and more robust than females. Males also posses a scent gland used to mark members of their colony with a distinctive odor; this gland is typically rudimentary or absent in females.
Range mass: female 4.0 g, 4.1 male to female 6.6 g, 7.0 male g.
Range length: 33 (high) mm.
Average wingspan: 0.222 m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Predators of dwarf dog-faced bats include owls, falcons, specifically the bat-falcon, and other raptors. Carnivorous bats, and snakes that manage to find a roosting site may also prey on dwarf dog-faced bats. When near humans, they may also be preyed upon by domestic cats.
Known Predators:
Dwarf dog-faced bats are thought to be polygynous, in which a male mates with more than 1 female during a single breeding season.
Mating System: polygynous
The breeding patterns of Dwarf dog-faced bats seem to vary with environment. Breeding begins ranging from July in southeastern Brazil to late August and early September in Paraguay. During pregnancy and lactation, females generally roost in maternity colonies separate from adult males. Females dwarf dog-faced bats give birth to a single offspring each year called a pup, however occasionally twins are born. The gestation period is approximately 2 to 3 months in length and offspring typically weigh 20 to 30% of the parents mass at birth. Weaning usually occurs at 5 to 6 weeks of age.
Breeding interval: Dwarf dog-faced bats breed once per year.
Breeding season: Dwarf dog-faced bats breed in mid to late winter.
Average number of offspring: 1.
Range gestation period: 2 to 3 months.
Range weaning age: 5 to 6 weeks.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual
Females dwarf dog-faced bats nurse their pups until they are weaned.
Parental Investment: pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female)
The dwarf dog-faced bat (Molossops temminckii) is a species of free-tailed bat from South America. It is found in Argentina, Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Paraguay and Uruguay, typically at lower elevations. It is one of two species in the genus Molossops, the other being the rufous dog-faced bat (M. neglectus). Three subspecies are often recognized, though mammalogist Judith Eger considers it monotypic with no subspecies. It is a small free-tailed bat, with a forearm length of 28.9–32.5 mm (1.14–1.28 in) and a weight of 5–8 g (0.18–0.28 oz); males are larger than females. It is brown, with paler belly fur and darker back fur. Its wings are unusual for a free-tailed bat, with exceptionally broad wingtips. Additionally, it has low wing loading, meaning that it has a large wing surface area relative to its body weight. Therefore, it flies more similarly to a vesper bat than to other species in its own family. As it forages at night for its insect prey, including moths, beetles, and others, it uses two kinds of frequency-modulated echolocation calls: one type is to navigate in open areas and to search for prey, while the other type is used for navigating in cluttered areas or while approaching a prey item.
Little is known about its reproduction, with pregnant females documented July through December in various parts of its range. Females might be capable of becoming pregnant multiple times per year, unlike some bats which have an annual breeding season. It roosts in small groups, typically three or fewer, which can be found under tree bark, in rocky outcrops or buildings, or even within holes in fence posts. Its predators may include owls, though the extent of owl depredation is unknown. It has a variety of internal and external parasites, including nematodes, cestodes, trematodes, mites, ticks, and bat flies.
The dwarf dog-faced bat was first named by Danish zoologist Peter Wilhelm Lund in 1842, who placed it in the now-defunct genus Dysopes, with a scientific name of Dysopes temminckii.[2][3] However, Lund's name was deemed a nomen nudum ("naked name", or unaccepted due to inadequate taxon description), and thus Lund is not recognized as the taxonomic authority. Instead, the authority is given as German zoologist Hermann Burmeister, who was judged to have adequately described the taxon in 1854.[4][3] The holotype had been collected in Lagoa Santa, Minas Gerais, Brazil.[5] American zoologist Gerrit Smith Miller Jr. was the first to use its present name combination, placing it in the genus Molossops in 1907.[6][5] The eponym for the species name "temminckii " is Dutch zoologist Coenraad Jacob Temminck.[7]
A variable number of subspecies are recognized. Four subspecies of Molossops temminckii have been named: M. t. temminckii, M. t. griseiventer, M. t. sylvia, and M. t. mattogrossensis. The former three are still recognized as subspecies by some, though M. t. mattogrossensis is now most frequently recognized not only as a distinct species, but also in a separate genus, Neoplatymops mattogrossensis.[3] Mammalogist Judith Eger, however, did not recognize any subspecies in Mammals of South America (2008).[3][5] The dwarf dog-faced bat and the rufous dog-faced bat (M. neglectus) are the only two species in the genus Molossops. Genetic analysis suggests that the Molossops species are closely related to those in the genus Cynomops; they are in a clade along with the genera Eumops, Molossus, Promops, Nyctinomops, and Neoplatymops.[3]
The dwarf dog-faced bat is considered small for the free-tailed bat family, Molossidae. Individuals have a total length of 60–84 mm (2.4–3.3 in), forearm length of 28.9–32.5 mm (1.14–1.28 in), and tail length of 21–34 mm (0.83–1.34 in). It weighs 5–8 g (0.18–0.28 oz). It is sexually dimorphic, with females smaller than the males; this is particularly noticeable in skull measurements. Its fur coloration is variable; back fur ranges from dark to light brown, with individuals found in forested areas darker than those in more arid ones. The belly fur is lighter in color and typically grayish. Its ears are small and triangular, with triangular tragi (cartilage projections in front of the ear canal). Its skull has a flattened top, with a weak sagittal crest. Its snout is long and flat, with a blunt tip and smooth lips. The nostrils are surrounded by wart-like bumps. Males have a gular gland used for scent marking members of a colony.[3] It has a dental formula of 1.1.1.31.1.2.3 for a total of 26 teeth.[10]
It has short thumbs with a well-developed pad at the base of each. It has distinct calcars (cartilage spurs) on the edge of its uropatagium (tail membrane); the calcars are more than half the length of the hind foot to the tail. Its wings attach to its hind limbs at the middle of the tibia. Its wings are large and broad, and it has low wing loading, meaning that it has a large wing area relative to its body weight.[3] Its wingtips are exceptionally broad for a free-tailed bat.[11] The dwarf dog-faced bat can differentiated from the rufous dog-faced bat by its smaller size; the latter typically has a forearm length greater than 36 mm (1.4 in).[12]
Overall, little is known about its reproduction. Pregnant females have been found in July in Venezuela, September and December in Brazil, September in Bolivia, and October and November in Argentina. Some authors have hypothesized that females may be polyestrous, or capable of becoming pregnant multiple times a year.[3] Two pregnant females found in Argentina each had a litter size of one offspring.[13]
The dwarf dog-faced bat is moderately social, typically roosting in small groups of no more than three individuals. Groups of up to fifteen have been found roosting under the bark of Pithecellobium trees. It has flexible roosting needs, and can use rocky outcrops, buildings, tree hollows, or hollow fence posts for roosting. It is nocturnal, with individuals leaving their roosts around dusk to forage.[3]
The dwarf dog-faced bat is an insectivore, catching insects mid-flight. It is relatively slow for a free-tailed bat, which are generally adapted for high speeds, and has flight characteristics more similar to a vesper bat. Its predicted flight speed is 6.3 m/s (23 km/h; 14 mph). It uses echolocation to navigate and locate prey, utilizing two kinds of calls. The first kind of calls are upward-sloping, frequency modulated calls, starting at around 40 khz frequency and ending at 50 kHz. The calls' duration is relatively long, at an average of 7.8 miliseconds, and they are more spaced out, with 97 miliseconds between calls. These calls are used when searching for prey or navigating in uncluttered space. The second kind of calls are downward-sloping, frequency modulated calls, starting at around 65 – 70 kHz and ending at 30 – 35 KHz. These calls have a shorter duration (4.7 miliseconds) and occur closer together (interpulse interval of 50.8 miliseconds). They are used while navigating in more cluttered environments, or when approaching a prey item. Its echolocation characteristics are considered unusual for a free-tailed bat, as it uses short, frequency modulated calls at high frequencies spaced close together. These echolocation characteristics are adapted for differentiating small prey items from background clutter such as vegetation. Its diet includes beetles, moths, flies, true bugs, Hymenoptera species, and grasshoppers and katydids.[3]
Little is known about its natural predators, but its remains were once documented within the pellet of a barn owl in Argentina. Its endoparasites (internal parasites) include cestodes in the genus Vampirolepis; nematodes of the genera Allintoshius, Capillaria; and Molostrongylus, and trematodes of the genera Anenterotrema, Ochoterenatrema, and Urotrema. Its ectoparasites (external parasites) include the ticks Ornithodoros hasei and Amblyomma; the mites Chiroptonyssus venezolanus, Spinturnix americanus, Macronyssus, Trombicula, Steatonyssus, and Chiroptonyssus; the bat flies Basilia carteri (Nycteribiidae) and Trichobius jubatus (Streblidae); and true bugs of the genus Hesperoctenes.[3]
The dwarf dog-faced bat is found only in South America, with a wide range encompassing Argentina, Bolivia, Brazil, Colombia, Ecuador, Guyana, Paraguay, Peru, Uruguay, and Venezuela.[1] The proposed subspecies M. t. sylvia is known from Corrientes Province, Argentina and Uruguay. Molossops temminckii griseiventer is known from Colombia in the Magdalena River Valley, as well as the Tolima, Meta, and Cundinamarca Departments. The nominate subspecies, M. t. temminckii, has been reported from Paraguay, northern Argentina, and several Brazilian states.[14] The species is generally found in lower altitude areas. The greatest elevation record for this species is 770 m (2,530 ft) above sea level, which was in Colombia. It has been found in a variety of biomes and ecoregions, including the Amazonian lowlands, Cerrado (tropical savanna), Caatinga (dry shrubland), Pantanal (wetlands), Atlantic Forest, Alto Paraná Atlantic forests, and Argentine Espinal.[3]
{{cite journal}}: Cite journal requires |journal= (help) The dwarf dog-faced bat (Molossops temminckii) is a species of free-tailed bat from South America. It is found in Argentina, Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Paraguay and Uruguay, typically at lower elevations. It is one of two species in the genus Molossops, the other being the rufous dog-faced bat (M. neglectus). Three subspecies are often recognized, though mammalogist Judith Eger considers it monotypic with no subspecies. It is a small free-tailed bat, with a forearm length of 28.9–32.5 mm (1.14–1.28 in) and a weight of 5–8 g (0.18–0.28 oz); males are larger than females. It is brown, with paler belly fur and darker back fur. Its wings are unusual for a free-tailed bat, with exceptionally broad wingtips. Additionally, it has low wing loading, meaning that it has a large wing surface area relative to its body weight. Therefore, it flies more similarly to a vesper bat than to other species in its own family. As it forages at night for its insect prey, including moths, beetles, and others, it uses two kinds of frequency-modulated echolocation calls: one type is to navigate in open areas and to search for prey, while the other type is used for navigating in cluttered areas or while approaching a prey item.
Little is known about its reproduction, with pregnant females documented July through December in various parts of its range. Females might be capable of becoming pregnant multiple times per year, unlike some bats which have an annual breeding season. It roosts in small groups, typically three or fewer, which can be found under tree bark, in rocky outcrops or buildings, or even within holes in fence posts. Its predators may include owls, though the extent of owl depredation is unknown. It has a variety of internal and external parasites, including nematodes, cestodes, trematodes, mites, ticks, and bat flies.
