Chaerephon pumilus

68. Little Free-tailed Bat Chaerephon pumilus French: Petite Tadaride / German: Kleine Bulldogfledermaus / Spanish: Caerepon pequeno Other common names: Lesser Free-tailed Bat, Little Wrinkle-lipped Bat, White-bellied Free-tailed Bat Taxonomy. Dysopes pumilus Cretzschmar in Ruppell, 1830, Massawa, Eritrea. The taxonomic limits of Chaerephon pumilus remain uncertain, and many named forms are currently synonymized within it. Until recently, populations from Madagascar and the western Seychelles were included, but recent molecular studies have proposed they be split as distinct species, under the names leucogaster (Madagascar, Comoro and Pemba islands, and parts of the African mainland) and pusillus (Seychelles). Furthermore, eastern Madagascan populations formerly attributed to C. pumilus have been described as another distinct species, C. atsinanana. Given the wide variability in morphology and echolocation-call structure among mainland African populations of C. pumilus, it has been suggested that several cryptic species remain to be described. While distinct molecular clades of African mainland C. pumilus can be distinguished, these do not correspond exactly with groups defined based on morphological or acoustic evidence. Molecular patterns revealed in the broader species complex (including pumilus sensu stricto, leucogaster, and pusillus) are partly suggestive of a “ring species” with different forms occurring down the eastern coast of Africa and in the western Indian Ocean islands including Madagascar. Monotypic. Distribution. Widely but disjunctly from Senegal E to Eritrea, Ethiopia, and Somalia, and S (including Bioko I) through DR Congo, Uganda, Kenya, Rwanda, Burundi, Tanzania (including Pemba and Unguja Is in Zanzibar Archipelago), Angola, Zambia, Malawi, Namibia (Caprivi Strip), Botswana, Zimbabwe, Mozambique, Swaziland, and E South Africa (Limpopo, Mpumalanga, and KwaZulu-Natal provinces); also in SW Arabia (extreme SW Saudi Arabia and W Yemen). Descriptive notes. Head-body ¢.42-67 mm, tail 24-40 mm, ear 9-19 mm, hindfoot 5-10 mm, forearm 32-42 mm; weight 6-16 g. Pelage of the Little Free-tailed Bat is short and velvety, highly variable in color, from almost black or brown to grayish brown or reddish brown above, without grizzling or white spots; slightly paler below, with highly variable mid-ventral markings (white belly-stripe broad to narrow to absent) and variable flank-stripe (white to off-white to absent). Upperlip has 5-7 or more well-defined wrinkles on each side and many spoon-hairs. Ears are black or dark brown, relatively short, not reaching snout when laid forward, and joined by interaural band of skin that covers interaural pocket, which contains erectile hairs giving rise to a short crest in males. Tragusis very small, squarish or sometimes with small lobe at top of posterior margin, and concealed by antitragus. Antitragus is much larger than tragus, roughly semicircular. Wing membranes may be blackish brown or white (two distinct forms, with intermediates), and tail membrane is blackish brown. Anterior palatal region is either closed or emarginated, and basisphenoid pits are moderately deep. M? has third ridge nearly as long as second ridge. Chromosomal complement has 2n = 48 and FNa = 58 (Uganda, Cameroon, Somalia) or 2n = 48 and FNa = 66 (Namibia, South Africa). Habitat. Little Free-tailed Bats occur throughout a wide variety of savanna types including undifferentiated woodlands, Isoberlinia (Fabaceae) woodland, rainforest grassland mosaics (Guinea savanna), wetter and drier miombo woodlands, coastal mosaics, Acacia (Fabaceae)— Commiphora (Burseraceae) bushland and thicket, and other thicket bushlands. They are not found in lowland rainforest but have been recorded from swamp forests in DR Congo. They also forage actively over agricultural areas including sugarcane fields and macadamia orchards, as well as urban and suburban areas. Food and Feeding. Little Free-tailed Bats are open-air foragers having long, narrow wings with high wing loading (11-8 N/m?®) and intermediate aspect ratio (8-6). Based on various studies involving microscope analyses of fecal pellets and stomachs, Little Free-tailed Bats typically feed on Coleoptera, Hemiptera, Lepidoptera, Hymenoptera, and Diptera. A 2011 molecular study (59 fecal pellets), conducted by K. Bohmann and coworkers in a sugarcane monoculture in Swaziland, yielded six orders (and 27 families) of insects (Coleoptera, Hemiptera, Isoptera, Lepidoptera, Diptera, and Trichoptera). Another molecular study, conducted by P. J. Taylor and coworkers in South African macadamia orchards in 2017, identified five orders (Coleoptera, Hemiptera, Lepidoptera, Orthoptera, and Blattodea), bringing to nine the number of insect orders known to be consumed by this species. A tenth order, Neuroptera, has also been identified based on microscopic examination of fecal pellets. Both aforementioned molecular studies revealed the presence in the diet of agricultural pest insects such as stinkbugs (Heteroptera, Pentatomidae) from agricultural ecosystems. The Swaziland molecular study also showed the prevalence of mosquitoes (Diptera, Culicidae, 27% prevalence in fecal pellets) in the diet. Diet varies geographically and seasonally, and in Durban, eastern South Africa: in summer, estimated volume percentages present were Coleoptera (47-7%), Hemiptera (32:8%), Lepidoptera (99%), Diptera (5-4%), and Trichoptera (4:2%); in winter, Lepidoptera (30-3%), Diptera (24%), Coleoptera (19-5%), Hymenoptera (11-:8%), Hemiptera (8%), and Trichoptera (6:5%) were present. In Kenya and also in the Kruger National Park in north-eastern South Africa, diet comprised mainly Hemiptera and Coleoptera, with some Lepidoptera. However, elsewhere in Kenya at Lake Naivasha, more than 50% of the diet comprised Diptera, with Coleoptera and Hemiptera consumed to a lesser extent; and at Amani Nature Reserve in north-eastern Tanzania, Blattodea was the major insect order in the diet (over 60% prevalence), with Hemiptera the only other insect order consumed. Breeding. After a c.60day gestation, the female gives birth to a single young (very rarely twins). There is a postpartum estrus, which allows three births per year in southern Africa (early November, late January, and March-April). A third parturition event in May occurs in Malawi. Indeed, Little Free-tailed Bats can breed up to five times within a year in equatorial forest habitat. Growth rates vary geographically. In Ghana, juveniles become volant by 19 days, are weaned at 21-28 days, reach adult weight by c.3 months, and attain sexual maturity at c.3 months (females) to five months (males). In Malawi, females attain sexual maturity in the following breeding season after their birth. Activity patterns. Little Free-tailed Bats are nocturnal. They emerge soon after dusk and forage throughout the night, with two activity peaks at dusk and dawn. Their natural roosts include crevices in rocks, trees and the crowns of palm trees, but they are very commonly recorded in the roofs of buildings in urban and rural areas. Echolocation calls are FM with narrow bandwidth, low frequency (typically peak frequency of 25 kHz), and long duration (c.10 milliseconds). Echolocation call structure and frequency vary geographically but some of the variation may be due to the use of different bat-detector systems. Movements, Home range and Social organization. Little Free-tailed Bats roost communally in groups that may number in the hundreds. Social organization of colonies may vary. In a 16month study in Ghana, colonies were organized into harems (female defense polygyny) occupying different day roosts and comprising one male with up to 21 adult females and their young. There was also an element ofterritoriality (resource defense polygyny). In a nine-month study of a colony at a day roost in Malawi, colony size varied from 20 to 30 bats and composition was variable; on average a ratio of approximately four females to one male was determined from individuals captured at emergence. In a study in Swaziland, the species traveled up to 4: 2 km from the roost to the foraging areas over sugarcane fields, and mean activity area varied from 976 ha to 1319 ha. In scent-choice experiments, males but not females were able to distinguish roost-mates from strangers, and conspecifics from non-conspecifics. Little Free-tailed Bats frequently share roosts in houses with Angolan Free-tailed Bats (Mops condylurus). Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. ACR (2017), Aspetsberger et al. (2003), Bohmann et al. (2011), Bouchard (1998, 2001b), Goodman & Ratrimomanarivo (2007), Goodman, Buccas et al. (2010), Happold, D.C.D. & Happold (1989), Happold, M. (2013a0), Lehmkuhl Noeret al. (2012), McWilliam (1988a), Mickleburgh, Hutson, Racey et al. (2014), Monadjem, Taylor et al. (2010), Naidoo, T., Goodman et al. (2016), Naidoo, T., Schoeman, Goodman et al. (2016), Naidoo, T., Schoeman, Taylor et al. (2013), Peterson et al. (1995), Taylor, Lamb et al. (2009), Taylor, Matamba et al. (2017), Taylor, Monadjem & Steyn (2013).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 648, DOI: 10.5281/zenodo.641827