Tadarida brasiliensis (I. Geoffroy, 1824)

Don E. Wilson & Russell A. Mittermeier, 2019, Molossidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 598-672 : 664

106.

Brazilian Free-tailed Bat

Tadarida brasiliensis

French: Tadaride du Brésil / German: Brasilianische Bulldogfledermaus / Spanish: Murciélago rabudo de Brasil

Other common names: Mexican Free-tailed Bat

Taxonomy. Nyctinomus brasiliensis 1. Geoffroy Saint-Hilaire, 1824 ,

“le district de Curityba [= Curitiba],” Parana, Brazil.

Recent genetic analyses suggest that subspecies designations need to be reevaluated, and that there are potential cryptic species requiring further study. Nine subspecies recognized.

Subspecies and Distribution.

T. b. brasiliensis I. Geoffroy Saint-Hilaire, 1824 — Costa Rica and Panama, SouthAmerica W of the Orinoco Basin and W & S of Amazon Basin, and Trinidad I.

T.b. antillularum G. S. Miller, 1902 — Puerto Rico S through the Lesser Antilles to Tobago I.

T. b. bahamensis Rhen, 1902 — Bahamas.

T. b. constanzae Shamel, 1931 — Hispaniola I ( Haiti and Dominican Republic).

T. b. cynocephala Le Conte, 1831 — E USA.

T. b. intermedia Shamel, 1931 — S Mexico (Chiapas) to Honduras.

T. b. mexicana Saussure, 1860 — W USA S to S Mexico (Oaxaca and Veracruz).

T. b. murina J. E. Gray, 1827 — Jamaica.

T. b. muscula Gundlach, 1861 — Cuba and Grand Cayman I.

Descriptive notes. Head—body 46-62 mm, tail 28-42 mm, hindfoot 7-11 mm, ear 14— 20 mm,forearm 36-47 mm; weight 8-15 g. Females are slightly heavier than males. Dorsal pelage ranges from light to dark brown, with hairs uniformly colored and short (2-3 mm) on trunk and head; ventral pelage is paler with slight frosting on tips and hairs slightly longer (3—4 mm). Cave-roosting bats may have light-colored fur because of effect of ammonia-fume bleaching. Albinism has also been reported in this species. Upper lip has deep vertical grooves, and overhangs lower lip. Ears are medium brown, rounded with small bumps on leading edge, reach nose tip when laid forward, and do not connect medially on forehead. Tragus is blunt and short, whereas antitragusis larger and rounded. Both sexes have a gular gland, but it is well developed only in adult males. Wing and interfemoral membranes are dark brown. Distal one-half oftail extends beyond uropatagium. Basisphenoid pits are undeveloped and anterior border of palate is emarginated. Upper incisors are not in contact. Dental formulais11/2,C1/1,P2/2,M 3/3 (x2) =300r11/3, C1/1,P2/2,M 3/3 (x2) = 32. Chromosomal complement has 2n = 48 and FN = 56.

Habitat. Dry forest, montane forest, pine-oak forest, thorn scrub, desert, and urban areas, but not in primary rainforest, as in the Amazon Basin. The Brazilian Free-tailed Bat occurs from sea level to 3000 m elevation.

Food and Feeding. The Brazilian Free-tailed Bat feeds mainly on moths ( Lepidoptera ), but also beetles ( Coleoptera ), ants ( Formicidae ), and flies ( Diptera ). It also forages at high altitudes to feed on migrating moths ( Noctuidae ).

Breeding. Most information is from populations in North America with few data from South America. In Florida, spermatogenesis begins in September, with mature spermatozoa present in the testes and epididymides primarily in February and March. Ovulation occurs chiefly during a 1week period in late March, which is followed by mating within the next 5 weeks, and births in June. In Mexico, mating season is probably in spring, and migration to the USA occurs in summer, with offspring born in late June and early July after a c.11week gestation period. In Ecuador, pregnant females have also been documented in August.

Activity patterns. Brazilian Free-tailed Bats emerge from cave roosts at dusk and large colonies may take several hoursto exit, all returning around dawn. The species roosts in caves, bridges, mine tunnels, culverts, and buildings. The search-phase echolocation call structure is QCF averaging c.26 kHz with a downward modulation, butis variable based on the local ambient noise produced by insects. Avian predators include American kestrels (Falco sparverius), Mississippi kites (Ictinia mississippiensis), red-tailed hawks (Buteo jamaicensis), greater roadrunners (Geococeyx californianus), great horned owls (Bubo virginianus), and common barn-owls (7yto alba). Mammalian predators include skunks (Mephitis mephitis and Conepatus mesoleucus), Northern Raccoons (Procyon lotor), and Northern Black-eared Opossums (Didelphis marsupialis). Snake predators include Texas rat snakes (Pantherophis obsoletus), coachwhips (Masticophis flagellum), copperheads (Agkistrodon contortrix), and eastern coral snakes (Micrurusfulvius).

Movements, Home range and Social organization. Colony size can reach up to 20 million individuals, in maternity cave roosts. There is partial segregation in roosts with females and their young, but some males may be present. Mothers recognize their young by scent and auditory cues. Smaller numbers of bats may also use a night roost. Individuals may fly long distances of 50 km or more to forage each evening. Of four migratory populations in the USA, two migrate south as much as 1840 km to Mexico for autumn and winter seasons. Other bat species found roosting with the Brazilian Free-tailed Bat include Peters’s Ghost-faced Bat (Mormoops megalophylla), the Big Brown Bat (Eptesicus fuscus), Rafinesque’s Big-eared Bat (Corynorhinus rafinesquii), the North American Evening Bat (Nycticeius humeralis), the South-eastern Myotis ( Myotis austroriparius), and the Cave Myotis (M. velifer).

Status and Conservation. Classified as Least Concern on The [UCN Red List. However, some caves with colonies of millions of bats have experienced population collapses due to human disturbance.

Bibliography. Arita & Ortega (2014), Eger (2008), Gamboa & Diaz (2018), Gillam & McCracken (2007), Jung et al. (2014), Krauel et al. (2018), Lee Yafu & McCracken (2001), Morales et al. (2018), Reid (1997), Russell et al. (2005), Speer et al. (2017), Tirira (2017), Wilkins (1989).

Figures

On following pages: 105. Roberts's Flat-headed Bat (Sauromys petrophilus); 106. Brazilian Free-tailed Bat (Tadarida brasiliensis); 107. European Free-tailed Bat (7adarida teniotis); 108. Egyptian Free-tailed Bat (7adarida aegyptiaca); 109. Kenyan Big-eared Free-tailed Bat (Tadarida lobata); 110. African Giant Free-tailed Bat (Tadarida ventralis); 111. Malagasy Free-tailed Bat (7adarida fulminans); 112. East Asian Free-tailed Bat (7adarida insignis); 113. La Touche's Free-tailed Bat (Tadarida latouchei); 114. New Guinea Free-tailed Bat (Austronomus kuboriensis); 115. White-striped Free-tailed Bat (Austronomus australis); 116. East Coast Free-tailed Bat (Micronomus norfolkensis); 117. Beccari's Free-tailed Bat (Ozimops beccaril); 118. Northern Coastal Free-tailed Bat (Ozimops cobourgianus); 119. Cape York Free-tailed Bat (Ozimops hall); 120. South-western Free-tailed Bat (Ozimops kitchener); 121. Loria’s Free-tailed Bat (Ozimops loriae); 122. Lumsden'’s Free-tailed Bat (Ozimops lumsdenae); 123. Inland Free-tailed Bat (Ozimops petersi); 124. Southern Free-tailed Bat (Ozimops planiceps); 125. Ride's Free-tailed Bat (Ozimops ride); 126. Hairy-nosed Free-tailed Bat (Setirostris eleryi).

Subspecies and Distribution. T. b. brasiliensis I. Geoffroy Saint-Hilaire, 1824 — Costa Rica and Panama , SouthAmerica W of the Orinoco Basin and W & S of Amazon Basin, and Trinidad I. T.b. antillularum G. S. Miller, 1902 — Puerto Rico S through the Lesser Antilles to Tobago I. T. b. bahamensis Rhen, 1902 — Bahamas . T. b. constanzae Shamel, 1931 — Hispaniola I ( Haiti and Dominican Republic ). T. b. cynocephala Le Conte, 1831 — E USA . T. b. intermedia Shamel, 1931 — S Mexico (Chiapas) to Honduras . T. b. mexicana Saussure, 1860 — W USA S to S Mexico (Oaxaca and Veracruz). T. b. murina J. E. Gray, 1827 — Jamaica . T. b. muscula Gundlach, 1861 — Cuba and Grand Cayman I.