Molossus rufus É. Geoffroy St.

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 : 146-147

Molossus rufus É. Geoffroy St. -Hilaire, 1805

Figure 37B

VOUCHER MATERIAL (TOTAL = 13): Jenaro Herrera (MUSM 6973), Nuevo San Juan (AMNH 273084, 273091, 273114, 273121, 273168; MUSM 15235–15239), Quebrada Betilia (MUSA 15194), Quebrada Sábalo (MUSA 15231); see table 64 for measurements.

UNVOUCHERED OBSERVATIONS: Ten individuals of Molossus rufus were captured, and others were detected using acoustic methods, during the CEBIO bat course at Jenaro Herrera in 2012.

IDENTIFICATION: The larger species of Molossus were recently revised by Loureiro et al. (2020), who split the taxon previously recognized as Molossus rufus into three species: M. rufus sensu stricto, M. nigricans , and M. fluminensis . As restricted by Loureiro et al. (2020), Molossus rufus can be distinguished from congeneric species by its dark dorsal pelage (varying from dark brown to blackish); dorsal hairs unicolored or, when bicolored, with a pale basal band covering no more than ¼ of the total length of each hair; dorsal hairs reaching 4.0 mm; forearm length averaging 50.3 mm in males (47.7–55.2) and 50.0 mm in females (46.7–54.0); greatest length

TABLE 64

External and Craniodental Measurements (mm) and Weights (g) of Molossus rufus

and Promops centralis from the Yavarí-Ucayali Interfluve

of skull averaging 22.9 mm (20.8–23.8) in males and 21.3 mm (19.9–22.6) in females; skull with inflated rostrum and elongated braincase; mastoid process directed laterally in posterior view; well-developed sagittal crest, particularly in males; basioccipital pits moderately deep; rostrum triangular in frontal view; and pincerlike upper incisors with converging tips (Loureiro et al., 2020).

Descriptions and measurements of Molossus rufus (which in the older literature was sometimes referred to by its junior synonym, M. ater ) were provided by Husson (1962, 1978), Dolan (1989), Barquez et al. (1999), Simmons and Voss (1998), Gregorin and Taddei (2000), Lim et al. (2005), Nogueira et al. (2008), Peters et al. (2012), Rengifo et al. (2014), Giménez and Giannini (2016), and Loureiro et al. (2018a, b, 2019, 2020). No subspecies are currently recognized (Loureiro et al., 2020).

Ascorra et al. (1993) identified the Jenaro Herrera specimen as Molossus ater , but they mistakenly reported its catalog number as MUSM 6974. Fleck et al. (2002) and Medina et al. (2015) correctly identified their specimens from Nuevo San Juan, Quebrada Betilia, and Quebrada Sábalo as Molossus rufus . Most of the voucher material we examined from the Yavarí-Ucayali interfluve conforms to previous descriptions and measurements of the species, but one specimen (MUSM 15235) has a supernumerary pair of lower incisors.

REMARKS: Of 10 recorded nocturnal captures of Molossus rufus accompanied by ecological information from our region, two were made in ground-level mistnets and eight in elevated nets; one individual was captured in primary forest, but the rest were netted in clearings.

We found five roosts of Molossus rufus near Nuevo San Juan (table 65), all of them in cavities

Figures

FIG. 37. Photographs of A, an adult Molossus molossus and B, an adult M. rufus, both captured at Jenaro Herrera. Photographs by Marco Tschapka.