Natalus tumidirostris G. S. Miller 1900
Creators: name: Don E. Wilson
name: Russell A. Mittermeier
Publisher: name: Lynx Edicions
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Chiroptera
Natalidae
Natalus
Natalus tumidirostris

description: 10.
Trinidadian Funnel-eared Bat
Natalus tumidirostris
French: Natalide a nez renflé / German: Trinidad-Trichterohr / Spanish: Natélido de Trinidad
Taxonomy. Natalus tumidirostris G. S. Miller, 1900,
“cave at Hatto, on north side of island of Curacao [Netherlands Antilles], West Indies.”
Three subspecies have been recognized, tumidirostrnis (Netherlands Antilles), continentis (mainland Venezuela), and haymantt (Trinidad), but they seem little more than color and body-size ecological variants: smaller and paler in more xeric habitats and larger and darker in wetter habitats. Monotypic.
Distribution. N South America (N Colombia, Venezuela, and the Guianas) and adjacent Is (Curacao, Bonaire, Trinidad, and Tobago); expected in N Brazil.
Descriptive notes. Ear 13-16-4 mm, forearm 35-42 mm (males) and 36-1-41-5 mm (females); weight 4-3-8-6 g (males) and 4-5-8-9 g (females). Dorsal pelage varies from whitish stramineous to rich orange-brown, usually unicolored, but if bicolored, hair bases are lighter than tips; venter is unicolored. There are dense mustache-like hair tufts along lateral margins of upper lip and across muzzle. Nostrils are round, relatively large, and point forward (rostrally).Medial and lateral ear margins are deeply concave; there are 5-6 ear pleats; pinna is funnel-shaped, with markedly pointed tip. Natalid organ of males is relatively flat, elliptical to wedge-shaped, and extends onto crown. Wings attach to tibia above ankle; free margin of uropatagium has sparse fringe of thin hairs; ungual tufts are absent. Braincase is inflated, rising abruptly from rostrum; premaxilla is not inflated; maxilla dorsal to molars is convex and inflated; postorbital region of skull in dorsal view has sides widely diverging rostrally; palate is absent between pterygoids; caudal margins of maxilla in ventral view form acute angle with longitudinal axis of skull; basisphenoid pits are shallow; mesostylar crest on third molar is absent.
Habitat. From dry cactus scrub to wet forest but most commonly areas of deciduous to semideciduous forest at elevations of 0-1400 m. The Trinidadian Funnel-eared Bat roosts in small to large caves. It roosts in warm and humid caves but avoids warmest areas in caves. In one roost on Paraguana Peninsula, Venezuela,it selected areas of c.30°C but moved to warmer (33°C) or cooler (28°C) spots when disturbed. Most caves known used by the Trinidadian Funnel-eared Bat are formed in limestone, and some can have high levels of ammonia. Roosts are unknown in the Guiana Shield, and all twelve records of species of Natalus from this area correspond to captures with mist nets. In that area, however, other cave-dwelling bats such as mustached bats (Pteronotus) and sword-nosed bats (Lonchorhina) have been found in caves formed by the accumulation of large boulders around eroding Precambrian granite inselbergs. It is likely that the Trinidadian Funnel-eared Bat also roosts in these types of caves in the Guiana Shield. In one occasion, three individuals were found roosting in a hollow rubber tree near Tamana Caves, Trinidad Island.
Food and Feeding. The Trinidadian Funnel-eared Bat feeds on insects and is reported to eat mostly species of Lepidoptera and Diptera.
Breeding. The Trinidadian Funnel-eared Bat seems to have a single annual estrus and bear only one young. Timing of reproduction varies among localities. In northern Colombia, parturition takes place before late March, and in northern Venezuela, 65% of females were still pregnant by late April. Throughout lactation, several hundred juveniles can aggregate in compact clusters on cave ceilings, which are visited by adult females. By the end of lactation in early June, these clusters break up, and adult-sized, gray-colored juveniles capable of full flight disperse. If juveniles are experimentally relocated to a nearby spot in the same cave, they continue to be nursed by their mothers. Sex ratios appear widely skewed in some caves, which can even contain individuals of only one sex, suggesting a pattern of sexual segregation similar to that of other natalids.
Activity patterns. Trinidadian Funnel-eared Bats are nocturnal. Nightly foraging begins around sunset, with exodus peaking one-half an hour later. Individuals continuously leave and enter their roost at least until 22:00 h. Flight of the Trinidadian Funnel-eared Bat is slow and very maneuverable. On the ground, it seems unable to crawl but can initiate flight vertically with strong downward thrusts of wings. While roosting, individuals hang widely spaced and are generally quiet, sometimes allowing themselves to be caught by hand. When other bat species abandon certain areas of a cave due to the presence of people, the Trinidadian Funnel-eared Bat is the last to leave roosting spots. Nonetheless, it becomes more alert while roosting when people repeatedly visit its cave. The Trinidadian Funnel-eared Bat dies in less than 20 hours of starvation or dehydration when kept in captivity. Its basal metabolic rate (1-54 ml O,/g/h) is 30% below the expected value for a mammal of similar body mass. This might be an adaptation to reduce risk of starvation and water loss when foraging in dry habitats. Thermoneutral zone of the Trinidadian Funnel-eared Bat is 28-35°C. It can maintain a stable body temperature of ¢.32°C in ambient temperatures of 20-28°C,falling into torpor below 20°C. With a relatively low thermal conductance (0-41 ml O,/g/h/°C), perhaps afforded byits long hair, the Trinidadian Funnel-eared Batis able to survive lower temperatures than other small Neotropical bats. Nonetheless,it dies if exposed to temperatures below 10°C for more than two hours.
Movements, Home range and Social organization. Trinidadian Funnel-eared Bats probably have small home ranges like other species of funnel-eared bats. High geographical structure of mitochondrial gene trees of Trinidadian Funnel-eared Bats suggests limited movement and gene flow over large geographical areas. It is reported to move between nearby roosting caves throughout the year, probably associated with reproductive activity. Ten other bat species can share roosts with the Trinidadian Funnel-eared Bat, but it has been found often forming mixed groups with only Seba’s Short-tailed Bat (Carolia perspicillata).
Status and Conservation. Classified as Least Concern on The IUCN Red List. In northern Venezuela, the Trinidadian Funnel-eared Bat seems ubiquitous and locally abundant and therefore not threatened. In Curacao, on the other hand, with an islandwide population ofjust 50-60 individuals,it seems highly threatened. Hatto Cave, the source of the holotype, is now a tourist attraction and has lost its colony of the Trinidadian Funnel-eared Bat. Without appropriate management, this island population might become extinct.
Bibliography. Cadena (1974), Charles-Dominique et al. (2001), Genoud et al. (1990), Gémez-Laverde (1986), Goodwin & Greenhall (1961), Linares (1998), Miller (1900c), Petit (1996), Riskin et al. (2005), Tejedor (2006, 2011).
description: Published as part of Don E. Wilson & Russell A. Mittermeier, 2019, Natalidae, pp. 589-596 in Handbook of the Mammals of the World – Volume 9 Bats, Barcelona :Lynx Edicions on page 595, DOI: 10.5281/zenodo.6811090