Nyctinomops femorosaccus, Merriam, 1889

Don E. Wilson & Russell A. Mittermeier, 2019, Molossidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 598-672 : 637

44.

Pocketed Free-tailed Bat

Nyctinomops femorosaccus

French: Nyctinomope a poche / German: Taschen-Bulldogfledermaus / Spanish: Nycténimo de bolsillos

Taxonomy. Nyctinomus femorosaccus Merriam, 1889 ,

“Agua Caliente [= Palm Springs], Colorado Desert [Riverside County], California,” USA.

This species is monotypic.

Distribution. SW USA (S California, C & S Arizona, extreme S New Mexico, and SW Texas) S to W Mexico (Guerrero, Morelos, and Puebla).

Descriptive notes. Head—body 60-75 mm, tail 31-47 mm, ear 19-24 mm, hindfoot 8-12 mm, forearm 44-49 mm; weight 11-18 g. Females are slightly smaller than males in cranial dimensions. Furis short; dorsal pelage is brown with white bases, and ventral pelage is slightly paler. Ears are large, thick, and leathery, and anteriorly united at bases of inner margins. A small rectangular tragus is present. Wings are long and narrow. A membranous sac is present between uropatagium and leg; it is also present to varying degrees in other species in the genus. Tail extends well beyond edge of uropatagium. Gular gland is well developed in adult males. Crown of M' has anterior width nearly equal to posterior width. Chromosomal complement has 2n = 48 and FN = 58.

Habitat. Dry tropical and subtropical habitats of deciduous forest, thorny forest, and scrubland, from sea level to 2250 m elevation.

Food and Feeding. Primary food item of the Pocketed Free-tailed Bat in June and July is moths ( Lepidoptera ), but in March and September is bugs ( Hemiptera ). Beetles ( Coleoptera ) are also common in its diet. To a lesser extent, terrestrial insects such as orthopterans are probably captured at roost sites.

Breeding. Pregnant females have been documented from the USA in April, June, and July, which suggests that there is only one young born per year. Lactating females were found in July, and subadults in August, in Texas.

Activity patterns. Pocketed Free-tailed Bats typically leave their roosts well after dark, an average of 45 minutes after sunset. They roost in rock crevices, in granite boulders, cliffs, and caves, and also in buildings and under rooftiles. Owls and snakes are known to prey on this species.

Movements, Home range and Social organization. The Pocketed Free-tailed Bat roosts in colonies of up to 60 individuals. In California, it has been reported occupying the narrower upper end of a large granite boulder crevice while Western Bonneted Bats ( Eumops perotis ) were found in the wider lower end.

Status and Conservation. Classified as Least Concern on The IUCN Red Lust.

Bibliography. Arita (2014c), Easterla & Whitaker (1972), Kumirai & Jones (1990), Matthews et al. (2010), Warner et al. (1974).

Figures

42. Mato Grosso Dog-faced Bat (Neoplatymops mattogrossensis), 43. Peale’s Free-tailed Bat (Nyctinomops aurispinosus), 44. Pocketed Free-tailed Bat (Nyctinomops femorosaccus), 45. Broad-eared Free-tailed Bat (Nyctinomops laticaudatus), 46. Big Free-tailed Bat (Nyctinomops macrotis), 47. Equatorial Dog-faced Bat (Cabreramops aequatorianus), 48. Rufous Dog-faced Bat (Molossops neglectus), 49. Dwarf Dog-faced Bat (Molossops temmancku), 50. Freeman's Dog-faced Bat (Cynomops freemani), 51. Mexican Dog-faced Bat (Cynomops mexicanus), 52. Southern Dog-faced Bat (Cynomops planirostris), 53. Cinnamon Dog-faced Bat (Cynomops abrasus), 54. Greenhall’s Dog-faced Bat (Cynomops greenhalli), 55. Thomas's Dog-faced Bat (Cynomops mastivus), 56. Miller's Dog-faced Bat (Cynomops milleri), 57. Waorani Dog-faced Bat (Cynomops tonkigui)

Distribution. SW USA (S California, C & S Arizona, extreme S New Mexico, and SW Texas) S to W Mexico (Guerrero, Morelos, and Puebla).