38. Western Bonneted Bat Eumops perotis French: Eumope de Schinz / German: Schinz-Bulldogfledermaus / Spanish: Eumops de Schinz Other common names: Greater Bonneted Bat, Greater Mastiff Bat, Western Mastiff Bat Taxonomy. Molossus perotis Schinz, 1821, “ Brasilien.” Restricted by C. C. Sanborn in 1932 to “Villa San Salvador, Campos des Goaytocasas, Rio Parahyba, Brazil.” Distributions of the two subspecies of E. perotis are highly disjunct, which might suggest distinct species. Two species recognized. Subspecies and Distribution. E.p.perotisSchinz,1821—scatteredrecordsfromSouthAmericainNVenezuela,SWEcuador,SWPeru,NBolivia,Paraguay,NArgentina,andEBrazil. E. p. californicus Merriam, 1890 — SW USA and N Mexico. Descriptive notes. Head-body 100-120 mm, tail 53-71 mm, ear 34-52 mm, hindfoot 14-19 mm, forearm 72-83 mm; weight 52-76 g. See general characteristics of the genus under the Black Bonneted Bat (E. auripendulus). Fur of the Western Bonneted Bat is grayish brown on back and slightly paler on venter. Ears extend beyond nose tip. Tragus is well developed and square-shaped. Lips are smooth and thick. Gular gland is well developed in adult males. Chromosomal complement has 2n = 48 and FN = 56 in Mexico and 2n = 48 and FN = 58 in Brazil. Habitat. Open dry habitats, farmland, and urban areas from 60 m below sea level in California to elevations of ¢. 3200 m in the Peruvian Andes. The Western Bonneted Bat occurs in low-growing chaparral of California, similar scrublands mixed with riparian woodland in New Mexico, dense stands of mesquite (Prosopis, Fabaceae) and willow (Salix, Salicaceae) in Texas, wetter tropical vegetation in south-western valleys of Zacatecas State in Mexico, and montane subtropical forests in Argentina. Food and Feeding. In Mexico, fecal samples of Western Bonneted Bats contained locusts (Orthoptera), spiders (Araneae), and bees (Apoidea). It also feeds on ants, moths, grasshoppers, dragonflies, leaf insects, beetles, and cicadas. Breeding. Parturition of Western Bonneted Bats occurs in June-August in the USA. Pregnant females were found in January and nursing females in September in Mexico; pregnant females were found in June-July in Texas. Juveniles were caught in July in California and December in Argentina. Activity patterns. Western Bonneted Bats can be active in a roost at any time but begin to move closer to the opening during afternoon and become vocal. They usually emerge 50-75 minutes after dusk and drop from the roost before attaining lift to fly off. They usually forage for several hours before returning to roosts before sunrise. They roost in tree holes, rock crevices, palm trees, caves, tunnels, bridges, and roofs of houses at least 2 m aboveground to enable them to take flight. Predators include peregrine falcon (Falco peregrinus), red-tailed hawk (Buteo jamaicensis), and common barn-owl (7yto alba). Movements, Home range and Social organization. The Western Bonneted Bat has been documented to move among three day roosts in crevices on a cliff face in California. Colonies of up to 100 individuals have been reported in the USA, but it also roosts alone. It is also known to roost with other species of bats in Mexico, including the Common Vampire Bat (Desmodus rotundus), the Gray Sac-winged Bat (Balantiopteryx plicata), the Arizona Myotis (Myotis occultus), and the Brazilian Free-tailed Bat (Tadarida brasiliensis). It has not been caught in June-August and December in Mexico, which suggests absence in summer and winter and migratory behavior, but extent of movements is unknown. Most roosts are not occupied throughout the year, suggesting that dispersal is common; however, in southern California and Arizona, it has been documented in every month of the year except January. Status and Conservation. Classified as Least Concern on The IUCN Red Lust. Bibliography. Aragon (2014), Baker (1970a), Barquez & Diaz (2001), Barquez et al. (1999), Best et al. (1996), Eger (1977 2008), Krutzsch (1955), Mares et al. (1996), Morielle-Versute et al. (1996), Sanborn (1932b), Smith & Genoways (1969).

Published as part of Don E. Wilson & Russell A. Mittermeier, 2019, Molossidae, pp. 598-672 in Handbook of the Mammals of the World – Volume 9 Bats, Barcelona :Lynx Edicions on page 633, DOI: 10.5281/zenodo.6418279