Thyroptera discifera

Abstract: only one genus, Thyroptera Spix, 1823, and three extant species: T. tricolor Spix, 1823, T. discifera (Lichtenstein and Peters, 1854), and T. lavali Pine, 1993. The disk-winged bats inhabit the Neotropical region, from Mexico to Southern Brazil (Wilson, 1978; Koopman, 1993; Pine, 1993), and its main generic diagnostic character is the presence of circular suction disks with short stalks on the soles of the feet and at the base of the well-developed claw of the thumb, which are histological and anatomically different from the Old World sucker-footed bat (Myzopoda sp.; see Nowak, 1999). Thyroptera tricolor is widely distributed through the Neotropical region occurring from southern Mexico to Bolivia, Trinidad, and southern Brazil, whereas T. discifera occurs from Nicaragua southwards to the Guianas and to at least 10°S in Peru, at 13°10’S and 64°13’W in Bolivia, and Belém, Pará State, and Aripuanã, Mato Grosso State, Brazil (e.g., Wilson and Findley, 1977; Wilson, 1978; Mok et al., 1982; Torres et al., 1988; Pine, 1993; Anderson, 1997; Herrera-Bernal et al., 1999; Nowak, 1999; Tschapka et al., 2000). Both species apparently occur in lowland forest areas. Thyroptera lavali is known from a few localities, including the type locality, Yavari Mirim River, Loreto Department (Pine, 1993), and at Camisea, Cuzco Department, and Alto Madre de Dios River, in Manu Biosphere Reserve, Peru (Solari et al., 2004), Orinoco Delta, Venezuela (Linares, 1998), Yasuni National Park, Napo Province, Ecuador (Reid et al., 2000), and Alter do Chão, Pará State, Brazil (Bernard and Fenton, 2002). Thyroptera tricolor and T. discifera may be distinguished by their size, the number of cartilaginous projections in the calcar and their fur color (Wilson and Findley, 1977; Wilson, 1978). Thyroptera lavali differs from both T. tricolor and T. discifera mainly by its larger size, larger free tail portion, wrist suction disk oblong, and more or less Acta Chiropterologica, 7(1): 165–188, 2005 PL ISSN 1508–1109 © Museum and Institute of Zoology PAS

Abstract: We report the first record of the disk-winged bat Thyroptera discifera (Chiroptera: Thyropteridae) found in Costa Rica and present observations on morphology and echolocation behavior of this poorly known species. Diet analysis showed the presence of Lepidoptera scales and spider fragments in the bat's feces. Echolocation calls showed very low intensity and consisted of several frequencymodulated harmonics. Behavior and echolocation calls, together with data from fecal samples, suggest a gleaning insectivore lifestyle for the species.

Abstract: Recent reports on the bats of Bolivia (Anderson and Webster, 1983; Anderson et al., 1982; Barquez, 1984) have added numerous species to its fauna but do not include Peters' disk-winged bat, Thyroptera discifera. Collections of bats and other mammals were made between 16 January and 15 February 1985, in Magdalena and La Cayoba, province of Itenez, department of Beni, as part of a survey by the Servicio Nacional de Control de Fiebre Hemorragica Boliviana. Herein, we report the presence of T. discifera that to our knowledge has not been previously collected in Bolivia. T. discifera differs from T. tricolor in having ... "venter only slightly paler than dorsum; calcar with a single cartilaginous projection extending into posterolateral border of uropatagium. Thyroptera tricolor usually is much paler ventrally than dorsally and has two cartilaginous projections on the calcar" (Wilson, 1978:1). On 25 January a group of 15 T. discifera (one later escaped) was obtained in a banana plantation in La Cayoba, ca. 30 km N Magdalena on the E bank of the Itonamas River. The capture site is characterized by small-scale argicultural plots, and the general plant formation for the area is mixed thermophile forest with about 25% of the trees being deciduous (Birot, 1970). The bats were inside a dry, furled banana leaf suspended 1.6 m above the ground. The sex ratio of 14 individuals was four males and 10 females. Of 10 specimens studied in detail, three were young with cartilaginous, evenly tapered metacarpo-phalangeal joints and seven were adults with knobby joints (Davis and Hitchcock, 1965). Wilson (1976, 1978) and Koopman (1982) described the distribution of Thyroptera discifera. The nearest known localities to La Cayoba are Cumaria, Loreto, Peru (Tuttle, 1970), ca. 1,130 km away and Aripuana, Mato Grosso, Brazil (Mok et al., 1982), ca. 570 km distant. Ranges of selected measurements of three adult specimens, two males and one female, are: length of forearm, 34.7-35.1; greatest length of skull, 14.4-14.9; condylobasal length, 13.2-13.8; zygomatic width, 6.7-7.0; least interorbital width, 2.5-2.7; and length of maxillary toothrow, 5.6-5.9. The subspecies, according to values given by Wilson (1976), is T. d. discifera. The specimens are housed in the collection of the Departamento de Ciencias Naturales, Universidad Nacional de Rio Cuarto. We thank Elio Massoia for critical reading of the earlier draft of the manuscript. We also are grateful to Gordon L. Kirkland, Jr. and to two anonymous reviewers for many helpful suggestions for improving the manuscript.