Glossophaga soricina

53.

Pallas’s Long-tongued Bat

Glossophaga soricina

French: Glossophage murin / German: Pallas-Blitenfledermaus / Spanish: Gloséfago de Pallas

Taxonomy. Vespertilio soricinus Pallas, 1766,

type locality not given. Restricted by G. S. Miller in 1912 to Suriname.

Prossible specific distinction of subspecies valens has been discussed by some authors, but no systematic assessment has been proposed. Five subspecies currently recognized.

Subspecies and Distribution.

G.s.soricinaPallas,1766—SouthAmericaEoftheAndesStoBolivia,Paraguay,SBrad,andNAching,eatinSorenandTrinidadIs.

G.s.antillarumRehn,1902—Jamaica.

G.s.handleyiWebster&J.K.Jones,1980—fromW&EMexicolowlandsthroughCentralAmericatoNWSouthAmerica(NW&WColombia).

G.s.muticaMerriam,1898—MariasIs,offPacificcoastofMexico.

G. s. valens G. S. Miller, 1913 — South America W of the Andes in W Ecuador and W Peru.

Descriptive notes. Head-body 45-59 mm, tail 5-12 mm, ear 9-15 mm, hindfoot 7-11 mm, forearm 32-38 mm; weight 7-12 g. Fur of Pallas’s Long-tongued Bat ranges from gray-brown to reddish brown (seldom dark brown); underparts are slightly paler, gray-brown with pale frosting. In more arid areas,it occasionally has yellowish fur from carotenoids associated with pollen of the tree Ceiba pentandra (Malvaceae). Pallas’s Longtongued Bat has moderately elongated rostrum that encloses tongue with hair-like papillae that can reach ¢. 40 mm into flowers. Nectar is extracted by dipping this hairy tongue repeatedly into nectar source at a high frequency of c.12 dips/second. Lowerjaw is about the same length as upper jaw. Lower incisors are small but well developed and in contact with each other; upper incisors are moderately procumbent.

Habitat. Wide variety of subtropical and tropical habitats ranging from arid thorn forests to rainforests and savannas up to elevations above 2500 m. Pallas’s Long-tongued Bat thrives in primary and secondary vegetation and readily occupies heavily modified agricultural and even urban areas, and it uses many man-made structures for roosting. Dueto this flexibility, it is probably the most widely distributed nectarfeeding bat in the Neotropics.

Food and Feeding. As nectarfeeding specialists, Pallas’s LLong-tongued Bats visit many flowering species—in fact, the most on record—and manyfruits throughout their large distribution. Food requirements of these small nectar specialists are enormous and can be 150-200% of body weight in nectar each night. Generally with rapid hovering flight, they visit many bat-pollinated plant species such as Crescentia spp. (Bignoniaceae), Agave spp. (Asparagaceae), various species of columnar cacti (Cactaceae), and trees such as Pseudobombax ellipticum (Malvaceae) and C. pentandra. Being extremely opportunistic, they occasionally exploit flowers from other pollination syndromes that offer larger amounts of nectar or pollen (e.g. insect-pollinated flowers of coconut palm, Cocos nucifera, Arecaceae), and they also regularly fed from hummingbird feeders. There are only a few reports of species of Glossophaga defending floral resources against conspecifics and other flowervisitors; resource defense seems to occur only at inflorescences offering particularly rich nectar supplies that will satisfy a significant part of nightly energy requirements. Pallas’s Long-tongued Bats are often the dominant nectarfeeding bat in commercial banana (Musa acuminata, Musaceae) plantations. Bananas are not native to the Neotropics, and although flowersstill producing significant quantities of nectar, cultivated plants no longer need pollination for fruit production. Consequently, Pallas’s Long-tongued Bats and other nectarfeeding bats sometimes have been regarded as pests because they were suspected to scratch young bananas with their claws while visiting flowers; these scratches increase in size during growth of the banana and can reduce their market value. Nevertheless, this species and other nectar specialists (Glossophaginae and Lonchophyllinae) are probably not the origin of such claw marks because they visit flowers almost always in hovering flight and therefore their claws only rarely touch and damage flowers or fruit. More probably, omnivorous spear-nosed bats (Phyllostomus) that can also be quite common are the culprits; they are much larger and heavier and always perch on banana inflorescence when drinking nectar. Although all morphological adaptations of Pallas’s Long-tongued Bats point to specialization on a nectar diet, they regularly eat soft fruits (e.g. Cecropia, Urticaceae and Piper, Piperaceae) and smaller fruits of Ficus spp. (Moraceae). Mastication with premolars and molars extracts primarily fruitjuices, but some fruit pulp and seeds are swallowed. Pallas’s Long-tongued Bats regularly eat insects (e.g. moths and small beetles) that they capture in flight. At some locations, they switch seasonally between diets dominated by nectar and diets with increased use offruit and insects.

Breeding. Reproduction of Pallas’s Long-tongued Bat is generally bimodal, often with birth peaks in dry and wet seasons. Parturition dates vary throughout the distribution and seem to depend locally on plant phenology and resource availability. Young are not born naked but have short gray fur. They are nursed for c.2 months and startto fly at ¢.20-25 days. A few weeks after birth, non-volant young start to regularly lick their mothers’ snouts to be fed regurgitated nectar.

Activity patterns. Pallas’s Long-tongued Batis strictly nocturnal, leaving roosts after full darkness. Some evidence suggests bimodal night activity pattern, with first peak just after dusk and second peakjust before dawn. Other evidence suggests a unimodal pattern, with greatest activity occurring three hours after sunset. Emergence is inhibited by high light intensities (daytime or intense moonlight). Pallas’s Long-tongued Bat roosts in many natural and anthropogenic structures such as hollow trees, caves, abandoned houses, mines, and culverts.

Movements, Home range and Social organization. Roosts range from small groups of 5-10 individuals in small tree hollows up to several hundred individuals in cave roosts and abandoned buildings. Because of their wide distribution, Pallas’s Long-tongued Bats can share roosts with as many as 30 bat species but most commonly with Seba’s Short-tailed Bats (Carollia perspicillata) in natural roosts and man-made structures.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Pallas’s Long-tongued Bat is probably the most abundant and widely distributed small nectarfeeding bat in the Neotropics.

Bibliography. Alvarez et al. (1991), Bonaccorso (1979), Clare et al. (2014), Geiselman & Defex (2015), von Helversen & von Helversen (1975), von Helversen & Winter (2003), Hoffmann & Baker (2001), Knérnschild etal. (2010), Lemke (1984), MacSwiney et al. (2012), Miller (1912), Reid (2009), Rose et al. (2019), Stephens & Tyson (1975), Tschapka (2003), Winter & von Helversen (2003).