183.

Argentine Serotine

Eptesicus furinalis

French: Sérotine tropicale / German: Argentinien-Breitfligelfledermaus / Spanish: Eptesicus de Argentina

Other common names: Argentine Brown Bat, Argentinian Brown Bat

Taxonomy. Vespertilio furinalis d’Orbigny & P. Gervais, 1847,

Corrientes, Argentina .

Based on the original description of E. dorianus by G. E. Dobson in 1885, it was previously considered a synonym of E. furinalis; however, later qualitative and quantitative morphological traits of the holotype of E. dorianus most resembled E. brasiliensis . Moreover, there is no certainty about origin of this holotype, or if it could have been changed with other specimens at some point. Therefore, the name E. dorianus was considered a nomen dubium (dubious name) that it could not be assigned to any taxon. Two subspecies recognized.

Subspecies and Distribution.

E.f.furinalisd’Orbigny&P.Gervais,1847—C,E,SE&SBrazil,C&SBolivia,Paraguay,Uruguay,andN&CArgentina.

E. f. gaumeri J. A. Allen, 1897 — from Mexico (Jalisco, Morelos, and Tamaulipas) S through Central America into South America, including Colombia, Venezuela, the Guianas, Ecuador, Peru, and Amazon Basin of Brazil and Bolivia.

Descriptive notes. Head-body 48-64 mm, tail 30-49 mm, ear 12-15 mm, hindfoot 5:6-11 mm, forearm 36-42-5 mm; weight 7-14 g. Females are larger than males. Dorsal hairs of the Argentine Serotine are bicolored, with blackish to dark brown bases and dark brown to yellowish brown tips; color of dorsal fur depends on season and habitat. Ventral hairs have dark brown bases and yellowish brown to whitish tips, sometimes washed with gray. Membranes are naked and dark brown to blackish. Ventral side of uropatagium is grayish, with scattered whitish hairs. Ears are dark brown, mediums-sized, and well separated, with rounded tips; tragus is long and pointed. Nose is broad. Skull is robust; rostrum is flattened, sloping upward to braincase; sagittal crest is poorly developed but visible; lambdoidal crest is visible; basisphenoid pits are absent; zygomatic arches are thin, strong, and slightly widened medially; pterygoids are well developed; and tympanic bullae are large. Upper inner incisors are separated, bilobed, and spatulated; I’ is reduced, conical, and separated from C' by small gap; P* is well developed, reaching one-third of C! height; M' and M? are almost square, with W-pattern; M? is reduced and triangular; lower incisors are trilobed and in contact, filling all space between canines; P, is small, reaching one-third of P, height; and lower molars have well-developed cusps, decreasing in size from M, to M,. Chromosomal complement has 2n = 50 and FN = 48, with acrocentric autosomes, large submetacentric X-chromosome, and small acrocentric Y-chromosome.

Habitat. Wide variety of habitats including evergreen forests, cloud forests, deciduous forests, riparian forests, temperate forests, savannas, swamps, and orchards from sea level up to elevations of ¢. 1800 m. The Argentine Serotine is commonly associated with water surfaces and moist habitats, but it is also known from drier habitats (e.g. shrubtree savanna and thorn-scrub associations).

Food and Feeding. The Argentine Serotine is insectivorous. At dusk, it has slow and erratic flight, with circular paths 6-9 m high and c.15-30 m in diameter. Later in the night, individuals fly low and at high speeds in open areas. Insects are captured over and through treetops and over streams and ponds.

Breeding. Pregnant Argentine Serotines with two embryos each were captured in April-May in Central America; pregnant females were also captured in January, March, and June in Central America and South America. Lactating females were captured in February, late May, late July, and August in Central America and South America. Newborns were observed in August andJanuary in Central America and South America. Available data suggest that breeding pattern is bimodal, with gestation of little more than two months and litter sizes of 1-2; parturition takes place during warmer months. Copulation occurs in May-June, and sperm is stored for 2-3 months before fertilization occurs. First pregnancies occur in July-November, and second pregnancies occur immediately after the first parturition during postpartum estrus. Second litter is born in January.

Activity patterns. Argentine Serotines are nocturnal. Individuals were observed flying right after sunset. Roosts have been found under loose bark and in hollow trees, holes in standing snags, caves, and buildings. They probably do not hibernate, but daily torpor possibly occurs. Echolocation calls are FM and sweep down from ¢.56 kHz to 35-45 kHz. Calls have durations of 5-9 milliseconds, mean interpulse interval of c.140 milliseconds, and frequency of maximum energy of c¢.40 kHz.

Movements, Home range and Social organization. The Argentine Serotine is usually found in colonies of 10-20 individuals, but colonies of 100 and even 100,000 individuals (Mexico) have been reported. It will share roosts with Jamaican Fruit-eating Bats (Artibeusjamaicensis), Great Fruit-eating Bats (A. lituratus), Toltec Fruit-eating Bats (A. toltecus), Little Yellow-shouldered Bats (Sturnira lilium), Common Vampire Bats (Desmodus rotundus), Black-winged Little Yellow Bats ( Rhogeessa tumida), and Mexican Dog-faced Bats ( Cynomops mexicanus).

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Argentine Serotine is widely distributed and locally common, occurs in protected areas, has a presumably large population, and seems to be tolerant to some degree of habitat modification.

Bibliography. Arias-Aguilar et al. (2018), Barquez, Mares & Braun (1999), Barquez, Perez et al. (2016b), Bianconi & Pedro (2017), Davis, W.B. (1966), Davis, W.B. & Gardner (2008), Dobson (1885), Medellin (2014b), Mies et al. (1996), Simmons (2005), Simmons & Voss (1998), Vizotto & Taddei (1973), Williams (1978).