180.

Diminutive Serotine

Eptesicus diminutus

French: Petite Sérotine / German: Kleine Breitflligelfledermaus / Spanish: Eptesicus pequeno

Taxonomy. Eptesicus diminutus Osgood, 1915,

“Sao Marcello, Rio Preto, Bahia, Brazil.”

G. E. Dobson in 1885 considered E. diminutus a synonym of E. dorianus, but qualitative and quantitative morphological traits of the holotype most resemble E. brasiliensis . Moreover, there is no certainty about the origin of this holotype, or if it could be changed with other individuals at some point. Therefore, the name E. dorianus was considered a nomen dubium (dubious name), and the next available name, E. diminutus, was applied to the taxon. An isolated population in Venezuela is probably a new subspecies or species. Two subspecies recognized.

Subspecies and Distribution.

E.d.diminutusOsgood,1915—NVenezuelaandEBrazil.

E. d. fidelis Thomas, 1920 — S Brazil, Paraguay, Uruguay, and N & C Argentina.

Descriptive notes. Head-body ¢.45-63 mm,tail 33-42 mm, ear 11-13-6 mm, hindfoot 6-10 mm, forearm 30-37-8 mm; weight 4-5-7 g. Females are larger than males. Dorsal hairs of the Diminutive Serotine are bicolored, with dark brown bases and brown to yellowish brown tips; sometimes extreme distal parts of hairs can be much paler, giving slightly frosted appearance. Ventral hairs have dark brown bases and pale brown to whitish tips. Some populations in Argentina have generally brown to dark brown fur, with almost unicolored hairs and slightly lighter venter. Ears are medium-sized, with rounded tips, and are well separated; tragusis relatively broad and short. Membranes are dark grayish to blackish. Skull is short and slender; sagittal crest is poorly developed but visible; lambdoidal crests are visible; 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 onethird 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, a large submetacentric X-chromosome, and a small acrocentric Y-chromosome.

Habitat. Dry tropical and subtropical forests in primary and secondary forests, open areas, grasslands, dense forests, and urban areas from sea level up to elevations of c. 1157 m. Diminutive Serotines have been caught on forest edges, in clustered environments, and over streams.

Food and Feeding. The Diminutive Serotine is insectivorous. Stomach contents had fragments of Coleoptera, Lepidoptera, and Diptera .

Breeding. Lactating Diminutive Serotines and a juvenile were captured in late January in southern Brazil.

Activity patterns. Diminutive Serotines roost under loose bark, hollow trees, and buildings. Echolocation calls have high frequencies of ¢.80 kHz and low frequencies of c.40 kHz. Calls are c.1-8 milliseconds in duration, mean interpulse interval is 50 milliseconds, and frequency of maximum energy is c.66 kHz.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCNRed List. The Diminutive Serotine is widely distributed and found in protected areas, but it is not locally common.

Bibliography. Arias-Aguilar et al. (2018), Barquez et al. (1999), Bianconi & Pedro (2017), Davis, W.B. (1966), Davis, W.B. & Gardner (2008), Dobson (1885), Gonzalez & Barquez (2016a), Myers et al. (1983), Simmons (2005), Solari et al. (2013), Williams (1978).