Saccopteryx bilineata (Temminck, 1838)

Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, Bulletin of the American Museum of Natural History 2021 (451), pp. 1-201 : 22-25

Saccopteryx bilineata (Temminck, 1838)

Figure 7A

VOUCHER MATERIAL (TOTAL = 28): Isla Muyuy (MUSM 20978), Quebrada Blanco (MUSM 20980), Estación Biológica Madre Selva (MUSM

TABLE 8

External and Craniodental Measurements (mm) and Weights (g) of Saccopteryx bilineata

and S. canescens from the Yavarí-Ucayali Interfluve

30885, 30886), Jenaro Herrera (AMNH 278510; CEBIOMAS 87; MUSM 5499), Nuevo San Juan (AMNH 272672, 272673, 272811, 272863, 273082, 273102, 273127, 273152, 273166; MUSM 13252–13256, 15267–15271), Quebrada Pantaleón (MUSA 15250), Río Blanco (MUSA 15076); see table 8 for measurements.

UNVOUCHERED OBSERVATIONS: During the Sierra del Divisor Rapid Biological Inventory, 15 individuals of Saccopteryx bilineata were captured at Divisor (Jorge and Velazco, 2006). Additionally, three individuals were captured at Quebrada Buenavista during the Yavarí Rapid Biological Inventory (Escobedo, 2003), and another was captured at Frog Valley. Saccopteryx bilineata was also recorded using acoustic methods during the CEBIO bat course at Jenaro Herrera.

IDENTIFICATION: Saccopteryx bilineata is easily distinguished from other species in the genus by the following combination of traits: dorsal pelage and wing membranes blackish brown, paired longitudinal dorsal stripes white and conspicuous, forearm> 44 mm, maxillary toothrow usually> 7 mm, greatest width across molars (M3–M3)> 7 mm (Emmons and Feer, 1997; Hood and Gardner, 2008; López-Baucells et al., 2018). Descriptions and measurements of S. bilineata were provided by Sanborn (1937), Goodwin and Greenhall (1961), Husson (1962, 1978), Brosset and Charles- Dominique (1990), Jones and Hood (1993), Simmons and Voss (1998), Yancey et al. (1998a), and Lim et al. (2005).

There is some disagreement concerning the recognition of subspecies in Saccopteryx bilineata . Koopman (1994) recognized two subspecies: S. b. bilineata (west-central Mexico to Colombia, Ecuador, eastern Peru, northern Bolivia, northern and eastern Brazil, southern Venezuela, and the Guianas) and S. b. perspicillifer (northern Venezuela and the island of Trinidad). By contrast, Yancey et al. (1998a), Simmons and Voss (1998), and Simmons (2005) did not recognize any subspecies for S. bilineata . Simmons and Voss (1998) noted that although significant geographic variation may exist among some populations of S. bilineata ,

TABLE 9

Roosting Groups of Saccopteryx bilineata Observed near Nuevo San Juan

none of the subspecies recognized by other authors (e.g., Hood and Gardner, 2008) appear to be justified by specimens they examined. For a more complete description of the trinomial history of S. bilineata , see Simmons and Voss (1998); we follow those authors in not recognizing subspecies in S. bilineata .

Ascorra et al. (1993), Fleck et al. (2002), and Medina et al. (2015) correctly identified their material from Jenaro Herrera, Nuevo San Juan, Quebrada Pantaleón, and the Río Blanco as Saccopteryx bilineata . The voucher material we examined from the Yavarí-Ucayali interfluve conforms to previous descriptions of the species, with measurements that fall within the known range of intraspecific size variation.

REMARKS: Twenty recorded captures of Saccopteryx bilineata at Jenaro Herrera were made in ground-level mistnets, five in elevated nets, and two at a roost (between buttresses of a standing tree). Of the 25 mistnet captures at this locality, 15 were made in primary forest, 5 in secondary vegetation, 4 in clearings, and 1 on a river beach. At Nuevo San Juan, all of our captures were made at roosts (table 9), where this species was invariably found in deeply shaded but not completely dark situations—for example, just inside rotted-out central cavities in standing trees. Most roosts were in well-drained primary forest (often on hillsides or hilltops), but two were found in seasonally inundated floodplain forest. Recorded heights of roosting groups were between 3 and 15 m above the ground (the single roosting group encountered on a fallen tree was sheltered among the buttresses of a huge trunk several meters above the ground). Saccopteryx bilineata was usually found roosting without other species nearby, but one roosting group shared a fallen tree with a roosting group of Peropteryx pallidoptera . At Divisor, a colony of about 15 individuals was found roosting in a cave (Jorge and Velazco, 2006).

Our observations from Nuevo San Juan are consistent with other descriptions of the roosts of this very widespread species, which are typically found either in the rotted-out central cavities of standing trees or in recesses between the buttresses of standing trees (Goodwin and Greenhall, 1961; Bradbury and Emmons, 1974; Bradbury and Vehrencamp, 1976; Voss et al., 2016). In both situations, Saccopteryx bilineata occupies half-enclosed vertical concavities that are more heavily shaded than those occupied by its sympatric congener, S. leptura .

Figures

FIG. 7. Photographs of A, an adult female (ROM 122081) Saccopteryx bilineata and B, an adult male (ROM 122160) S. leptura, both captured at Jenaro Herrera. Photographs by Burton Lim.