Molossus pretiosus, G. S. Miller, 1902

Don E. Wilson & Russell A. Mittermeier, 2019, Molossidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 598-672 : 626

18.

Miller’s Mastiff Bat

Molossus pretiosus

French: Molosse de Miller / German: Mille-rSamtfledermaus / Spanish: Moloso de Miller

Other common names: Miller's Free-tailed Bat

Taxonomy. Molossus pretiosus G. S. Miller, 1902 ,

“La Guaira [Distrito Federal], Venezuela.”

This species is monotypic.

Distribution. Known from scattered localities in S Mexico (Guerrero and Oaxaca ), E Honduras, Nicaragua, Costa Rica, Colombia, Venezuela, Guyana, and CW & E Brazil; also on Trinidad I.

Descriptive notes. Head-body 72-80 mm, tail 39-44 mm, ear 16-17 mm, hindfoot 10-13 mm, forearm 44-51 mm; weight 20-28 g. Miller’s Mastiff Batis larger than all its congeners, except the Black Mastiff Bat ( M. rufus ). Dorsal hairs of Miller's Mastiff Bat are dark brown or black, with or without very thin pale band at bases, not covering more than one-quarter the hair length. Reddish orange dorsal pelage also occurs in some populations. Dorsal pelage is short (2-3 mm). Ventral pelage is lighter than dorsal pelage. Ears are rounded and arise from same point on forehead. Tragusis small, and antitragus is constricted at its base. Upperlip and snout are smooth and lack any medial ridge. Face, wings, and uropatagium are dark brown to black. Skull has elongated braincase, quadrangular occipital region, and infraorbital foramen opening laterally in frontal view. Basioccipital pits are very deep. I” is elongated, with parallel or convergenttips, but rarely thick and spatulated. Chromosomal complement has 2n = 48 and FN = 66.

Habitat. Dry and semideciduous forests, tropical dry forests, riparian forests, grassland savannas, caatinga, cerrado, dry woodlands, and cactus and thorn scrub.

Food and Feeding. Miller’s Mastiff Bat is an aerial insectivore, and Coleoptera , Lepidoptera , Hemiptera , and Hymenoptera have been found inits feces.

Breeding. Miller’s Mastiff Bat is polyestrous, and females can be simultaneously pregnant and lactating. In Nicaragua, pregnant females were reported in March-April and June and pregnant females with juveniles in mid-August. In Costa Rica, pregnant females were captured in May, July, and October, and young were present in July and October.

Activity patterns. Miller's Mastiff Bats have been observed leaving their roosts 5-15 minutes after sunset. They roost in caves, buildings, and hollow trees. Black-and-white owls (Ciccaba nigrolineata) are known to prey on Miller’s Mastiff Bats.

Movements, Home range and Social organization. Miller’s Mastiff Bat forms small groups of up to ten individuals. Colonies can be composed of individuals of only one sex, which are usually sexually inactive, or adults of both sexes and young. In reproductive colonies, females are more abundant than males, indicating a polygynous mating system. It has been found roosting with other congeners such as Pallas’s Mastiff Bat ( Molossus molossus ) and other genera such as the Broad-eared Free-tailed Bat ( Nyctinomops laticaudatus ).

Status and Conservation. Classified as Least Concern on The IUCN Red List. Miller’s Mastiff Bats occurs in a number of protected areas, has a wide distribution, and is tolerant of some habitat modification.

Bibliography. Claudio, Silveira, Farias & Lapenta (2018), Dolan (1989), Dolan & Carter (1979), Eger (2008), Freeman (1979, 1981), Ibanez et al. (1992), Jennings et al. (2000), Jones, Smith & Turner (1971), LaVal (1977), LaVal & Fitch (1977), Loureiro, Gregorin & Perini (2018), Marinkelle & Cadena (1972), Nogueira et al. (2008), Pineda et al. (2008), Simmons (2005), Timm & LaVal (1998).

Figures

1. Blunt-eared Bat (Tomopeas ravus), 2. Lesser Naked Bat (Chewromeles parvidens), 3. Greater Naked Bat (Chewromeles torquatus), 4. Peters’s Little Mastff Bat (Mormopterus jugularis), 5. Reunion Little Masuft Bat (Mormopterus francoismoutoui), 6. Mauritian Little Mastiff Bat (Mormopterus acetabulosus), 7. Sumatran Little Mastift Bat (Mormopterus doriae), 8. Least Little Mastiff Bat (Mormopterus minutus), 9. Kalinowski’s Little Mastiff Bat (Mormopterus kalinowskii), 10. Incan Little Masuft Bat (Mormopterus phrudus), 11. Alvarez’s Mastff Bat (Molossus alvarez), 12. Aztec Mastff Bat (Molossus aztecus), 13. Coiban Mastuff Bat (Molossus cotbensis)

Distribution. Known from scattered localities in S Mexico (Guerrero and Oaxaca ), E Honduras , Nicaragua , Costa Rica , Colombia , Venezuela , Guyana , and CW & E Brazil ; also on Trinidad I.