Thyroptera discifera ( Lichtenstein & Peters , 1854 ) ( Chiroptera : Thyropteridae ) : first record in the state of Sergipe , northeastern Brazil

In Brazil, Thyroptera discifera, Peters’ Discwinged Bat, occurs in the Amazon basin, Cerrado, and Atlantic Forest. A lactating female was captured in an Atlantic Forest fragment in Sergipe, northeastern Brazil. This specimen represents the first record for this species from the state and increases to 46 the number of bat species known from Sergipe. Our record extends the northeastern distribution limit of the species by approximately 317 km (from the nearest previous record at Salvador, Bahia). This record also supports a rainy season to lactation period for this species.

Thyroptera discifera can be distinguished from other thyropterids by being among the smallest members of the genus, and is most similar to T. wynneae.However, T. discifera has unicolored ventral pelage, whereas T. wynneae presents tricolored ventral pelage.The coloration of the pelage of T. discifera is yellow-brown and differs from other Thyroptera species, which vary from grayish to light brown (Velazco et al. 2014).Thyroptera discifera and T. lavali have one well-defined lappet but differ by a large body, bicolored ventral pelage, and a unicuspid third lower incisor in T. lavali (Pine 1993).Compared with T. devivoi, T. discifera has a tail with a short free portion, long and densely whitish hairs over the uropatagium, and long and non-woolly hairs between the shoulders (Gregorin et al. 2006).The circular disks on the thumbs are similar in T. discifera and T. tricolor, but this species differs in that T. tricolor has a calcar with two well-defined lappets, and the ventral pelage is paler than the dorsum (Wilson 1978).
An adult female of T. discifera (Figure 1) was collected during a survey of the bat fauna of Refúgio da Vida Silvestre Mata do Junco (RVSMJ) in Capela municipality (10°32′ S, 037°03′ W), eastern portion of the state of Sergipe, northeastern Brazil (Figure 2).The RVSMJ corresponds to one of the largest fragments of the Atlantic forest in the state (1,520 ha), and is classified as a subdeciduous forest remnant in different successional stages (Santos et al. 2007).It is surrounded by an anthropogenic matrix that is mostly includes sugar cane (Saccharum spp.) plantations.The rainy period in area is concentrated between the months of April and August (SINDA 2015).Morphological measurements obtained for the female of T. discifera in RVSMJ, falls within the range of variation for this species in Brazil (Pine 1993;Bezerra et al. 2005;Gregorin et al. 2006) (Table 1).
In Brazil, T. discifera has a disjunctive geographic distribution, having been recorded in the Amazon basin (Mok et al. 1982;Pine 1993;Sampaio et al. 2003;Velazco et al. 2014), Cerrado (Bezerra et al. 2005), and Atlantic Forest (Gregorin et al. 2006) (Figure 2).Our specimen represents the first record for the state of Sergipe and the second record from the Atlantic Forest (the previous record in Salvador, Bahia, in 1896), and this new record extends the distribution of T. discifera by approximately 317 km from the previously known northeastern limit (Figure 2).With this addition, the bat species richness for the RVSMJ and the state of Sergipe is increased to 20 and 46, respectively (according to Brito and Bocchiglieri 2012;Leal et al. 2013;Mikalauskas et al. 2014;Rocha et al. 2014).
The specimen, a lactating female, was captured with a mist net (7 × 3 m) about 1.6 m above the ground on 18 May 2012 at 20:00 h (license number 2011.05.0108/00113-011SEMARH/SE).After the capture, the skull of the specimen was removed and cleaned, while the body was preserved in 70% alcohol.The specimen was deposited at the Coleção de Mamíferos da Universidade Federal de Sergipe (CMUFS 0079).
The specimen was identified based on the characteristics described in Wilson (1978), Gregorin et al. (2006), and Velazco et al. (2014).The external and cranial measurements (in mm) were obtained using calipers (0.02 mm precision).Our specimen presented an unicolored, yellow-brown ventral pelage, a short forearm (34.6 mm) with slight hairiness, a calcar with one well-defined lappet, a tail with a short free portion (1.5 mm), and circular disks on the thumbs.Additionally our specimen presents a small foramen ovale.The first and second upper incisors are not in contact, the cusps on upper I2 are obliquely arranged relative to the long axis of the toothrow, and the lower I3 is taller than the others and has two small accessory cusps on each side.Similar to observed by Gregorin A B Thyroptera discifera has a slow and maneuverable flight that makes it difficult to capture in mist nets (Tschapka et al. 2000;Bezerra et al. 2005).In Venezuela and Bolivia, this species was captured in a banana plantation, inside dry leaves (Wilson 1978;Torres et al. 1988).The thyropterids often take shelter in leaves of species of Heliconiaceae, Marantaceae, Musaceae, and Urticaceae (Findley and Wilson 1974;Wilson 1978;Torres et al. 1988;Tschapka et al. 2000;Vonhof and Fenton 2004;Velazco et al. 2014).The abundance of species of Thyroptera, including T. tricolor, is probably limited by the availability of shelters (Findley and Wilson 1974;Vonhof and Fenton 2004).
The capture of this lactating female of T. discifera at Sergipe in May, seems to supports that lactation in this genus apparently is restricted to the rainy season (Findley and Wilson 1974;Solari et al. 2004;Dechmann et al. 2006).
Since the study of Rocha et al. (2010), the richness of bats in Sergipe increased from 27 to 46.However, different localities in this state have never been sampled or are undersampled.The intensification of inventories in the region will likely contribute to records of bat species new to northeastern Brazil and a better understanding of the distribution patterns of Brazilian bats.

Table 1 .
Measurements of Thyroptera discifera females from Brazil.The weight is expressed in grams and the external and cranial measurements are in millimeters.Bocchiglieri et al. | Thyroptera discifera in Sergipe, Brazil