Hylonycteris underwoodi Thomas 1903

73. Underwood’s Long-tongued Bat Hylonycteris underwoodi French: Hylonyctére d’Underwood / German: Underwood-Blattnase / Spanish: Hilonicterio de Underwood Taxonomy. Hylonycteris underwood: Thomas, 1903, “Rancho Redondo [San José], Costa Rica.” "Two subspecies are recognized. Subspecies and Distribution. H. uw. underwoodi Thomas, 1903 — disjunct from 8S Mexico (Veracruz) to E Guatemala, S Belize, and N & W Honduras, and from SE Nicaragua to W Panama. H. u. minor C. J. Phillips &J. K.Jones, 1971 — Pacific slope in Mexico, from Nayarit and Jalisco to S Oaxaca. A.p. discontinuous distribution with gap in Nicaragua might just reflect lack of data because Underwood's Long-tongued bat always occursat rather low densities and is therefore not very often captured. Descriptive notes. Head-body 48-60 mm, tail 3-10 mm, ear 9-13 mm, hindfoot 7-11 mm, forearm 31-5-36 mm; weight 6-5-8-5 g (adult, non-reproductive). Females are notably larger than males. Underwood’s Long-tongued Batis very small and delicate. Dorsal hairs are dark brown or blackish, faintly three-banded with bases dark gray, middles pale gray, and tips dark. Muzzle is greatly elongated and tapering, and lower jaw extends well beyond upper jaw. Noseleaf is short (3-4 mm) and narrow. Tail is present and shorter than naked uropatagium. Wing membranes attach to ankles. Underwood’s Long-tongued Batis characterized by absence of lower incisors and elongated snout that encloses long tongue. Dental formula is I 2 /0, C 1/1, P 2/3, M 3/3 (x2) = 30. Chromosomal complement has 2n = 16 and FN = 24. Habitat. Almost exclusively in vicinity of primary and older secondary forests, ranging from lowland rainforests at sea level up to cloud forests and higher to elevations of 2640 m. In Mexico, Underwood’s Long-tongued Bats were captured in pine forests while visiting large flowers of a thistle (Cirsium sp., Asteraceae). Food and Feeding. Underwood's Long-tongued Batis a nectar specialist and uses its long tongue to harvest nectar from a wide variety of flowers. It depends on year-round flower supply and visits flowers that occur in rather low densities scattered throughout forests. All individuals captured in north-eastern Costa Rica throughoutthe year carried pollen and more than 80% of pollen from the hemi-epiphyte Merinthopodium neuranthum (Solanaceae) and ¢.70% from canopy liana (Marcgravia, Macgraviaceae); both flower over rather long periods. Underwood’s Long-tongued Bat very rarely feeds on small and particularly soft fruits, such as those of Conostegia xalapensis (Melastomataceae) or Coussapoa oligocephala (Urticaceae). Breeding. In north-eastern Costa Rica, Underwood’s Long-tongued batis bimodally polyestrous, with pregnant females found in January-April and August—-October. A female in Guatemala had an enlarged uterus from a recent pregnancy in early March. Activity patterns. Underwood’s Long-tongued Batis nocturnal. It often roosts under rotting fallen logs or among buttresses of fallen trees that offer more than one exit. It also roosts in caves or anthropogenic tunnels or culverts. Movements, Home range and Social organization. Underwood’s Long-tongued Bat never occurs at high densities. It roosts alone or in very small groups of 1-4 individuals. Status and Conservation. Classified as Least Concern on The IUCNRed List. Underwood’s Long-tongued Bat probably depends on forests that provide year-round sufficient supplies of flowers for nectar, so habitat loss could become a conservation concern. Bibliography. Castro-Luna & Sosa (2009), Jones & Homan (1974), McCarthy et al. (1993), Reid (2009), Simmons (2005), Tschapka (1998, 2004), Turcios-Casco & Medina-Fitoria (2019).
Published as part of Don E. Wilson & Russell A. Mittermeier, 2019, Phyllostomidae, pp. 444-583 in Handbook of the Mammals of the World – Volume 9 Bats, Barcelona :Lynx Edicions on page 522, DOI: 10.5281/zenodo.6458594