Red fruit vampire
| Red fruit vampire | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Stenoderma | ||||||||||||
| É. Geoffroy Saint-Hilaire , 1818 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Stenoderma rufum | ||||||||||||
| Desmarest , 1820 |
The red fruit vampire ( Stenoderma rufum ) is the only species of the genus Stenoderma from the subfamily of the fruit vampires of the bats . The frugivorous animals are endemic to a few islands in the Antilles in two subspecies .
description
Appearance and dimensions
The fur of the red fruit vampire comes in different shades of brown, whereby it is always lighter on the back than on the belly. The animals are marked with characteristic white spots on the neck and on the dorsal, front wing base. The hair length varies between 6 and 8 mm. The fur of the young is lighter, grayer and stubby. The color of the coat is the most important distinguishing feature between the two subspecies. Adult animals of the Puerto Rican subspecies St. r. darioi have tan to dark chocolate brown fur, while the dorsal fur of the subspecies from the Virgin Islands St. r. rufum have lighter shades of brown to tan.
| 2 | · | 1 | · | 2 | · | 3 | = 32 |
They are around 65–70 mm long and weigh around 25–30 g. In the Puerto Rican subspecies, the females are larger than the males. This sexual dimorphism is significant, but weak (depending on the measurement parameter, 0% to 4% in adult animals); it is weaker to be observed even in young animals.
In the population on the Virgin Island of Saint John, this dimorphism is less pronounced, the females are the same size as the males from Puerto Rico, the males are only slightly smaller.
behavior
The red fruit vampire is a purely frugivore way contrary to the English common names Red Fig-eating Bat (Red coward ness end bat) has never been observed that the animals fig fruits devour. The main components of the fruits of the balata tree , the ant tree Cecropia schreberiana and the Prestoea palm Prestoea montana were found in the stomach contents of specimens caught in Puerto Rico . The food supply is very constant regardless of rainy and dry seasons and is so rich that even with grazed trees a large proportion of the fruit falls to the ground without being eaten.
The animals live solitary and stationary in relatively small action areas , which are significantly larger in young animals than in adult specimens. The red fruit vampire does not show territorial behavior , not even with regard to food sources. The animals choose their resting places opportunistically close to the current food supply; a resting place is rarely used more than once. The species shows less nocturnal activity than usual with fruit vampires , in general its movement pattern is strongly characterized by the strongest possible energy economy, since there are neither significant predators nor significant food competition.
Reproduction
The females are fertile and polyestrial year round , they can suckle and be pregnant with one at the same time . Birth is head first and takes about 15 minutes. Newborns weigh 4–7 g. Females lose up to 30% of their weight at birth.
The males do not keep harems and do not take part in the brood care. They do not defend any territories.
The sex chromosomes of the species are organized according to a XX / XY 1 Y 2 scheme.
distribution
The red fruit vampire occurs in two subspecies at the transition from the large to the Lesser Antilles in a distribution area of significantly less than 20,000 km². The western subspecies Stenoderma rufum darioi is mainly known from Puerto Rico, a catch of a young animal on the westernmost of the Spanish Virgin Islands, Vieques, indicates a population there. Overall, the animals are considered rare in Puerto Rico, only in the forest on and around the Luquillo Mountains are they considered common to very common. The eastern subspecies Stenoderma rufum rufum occurs on the American Virgin Islands , where it is known from all three main islands of Saint Croix , Saint John and Saint Thomas , but is very rare.
The animals appear on the islands of their occurrence in different habitats; in Puerto Rico they are typically found in dense rainforest , the only catch from Saint Croix comes from a secondary rainforest; the habitat on Saint John and Saint Thomas, on the other hand, is dry and has tree-like vegetation. In the Puerto Rican rainforest, the red fruit vampire is the most important carrier of endochoria for certain fruit-bearing trees.
Predators and parasites
There are no major predators of the species. However, it is attacked by the usual types of bat ectoparasites, known by name are a predatory mite , Periglischus iheringi , and several astigmata mites of the genus Paralabidocarpus . 35% of the specimens examined in Puerto Rico were infected with mites and carried an average of four mites. Young animals showed a significantly higher mite infestation than adult specimens, which is attributed to greater experience in removing the parasites. Overall, however, the animals are less affected by the mite infestation than the other bats in their habitat. This is attributed to the loneliness of the red fruit vampire.
Danger
The red fruit vampire is classified as endangered by the IUCN because of its small and shrinking habitat due to human influence.
Research history
The species was described in the 2nd decade of the 19th century using a specimen of unknown origin, first mentioned under the name Stenoderma rufum in 1816 by Lorenz Oken , the first scientific description of the genus followed in 1818 by Geoffroy, and the species two years later Desmarest. Since Geoffroy's work dealt with the first description of the zoology of Egypt, and the location of the holotype was unknown and is still today - after the red coat color it is now the subspecies St. r. rufum , more precisely attributed to the population on Saint John - the localization of the species was not possible for a long time. In the early 20th century, the species was located in the Caribbean because of its similarity to species there, which was confirmed by some bone finds in Puerto Rico in 1918 and 1925. It was not until the 1960s that living specimens were observed; first in Saint John, but very soon in Puerto Rico too.
Systematics
There are two recent subspecies - St. r. rufum (Virgin Islands) and St. r. darioi (Puerto Rico) - as well as a fossil-handed Puerto Rican subspecies - St. r. athonyi known.
The red fruit vampire forms together with the genera Ardops , Phyllops and Ariteus the Caribbean subtribe Stenodermatina of the tribe Stenodermatini of the fruit vampires .
Names
The generic name Stenoderma is derived from the two Greek words στενός / stenos = tight, narrow and δέρμα / derma = skin and refers to the very narrow interfermoral flight membrane ( uropatagium ). The type epithet rufum is derived from the Latin adjective rufus = red and refers to the red-brown color of the holotype . The name of the subspecies from the Virgin Islands rufum refers to the red coat color that is common in this subspecies, the two Puerto Rican subspecies are named in honor of two zoologists. The recent subspecies darioi according to Dario Valdivieso , the only fossil subspecies anthonyi according to Harold Elmer Anthony .
Individual evidence
- ↑ a b c d Hugh H. Genoways and Robert J. Baker: Stenoderma rufum . In: The American Society of Mammalogists (Ed.): Mammalian Species . No. November 18 , 1972 ( PDF , 407 kB).
- ↑ a b c J. Knox Jones Jr., Hugh H. Genowaysy and Robert J. Bakerz: Morphological Variation in Stenoderma rufum . In: Journal of Mammalogy . Vol. 52; No. 1, June 1971, p. 244-247 .
- ↑ a b c d e f Gary G. Kwiecinski and William C. Coles: Presence of Stenoderma rufum Beyond the Puerto rican Bank . In: Museum of Texas Tech University (Ed.): Occasional Papers . No. 266 , June 1, 2007 ( PDF , 488 kB).
- ↑ a b c d e f Michael R. Gannon: Bats of Puerto Rico: an island focus and a Caribbean perspective . Texas Tech University Press, Lubbock 2005, ISBN 0-89672-551-0 , pp. 108 ff .
- ↑ a b c d e Michael R. Gannon: Foraging ecology, reproductive biology, and systematics of the red fig-eating bat (Stenoderma rufum) in the Tabonuco Rain Forest of Puerto Rico (Diss.) . Texas Tech University , 1991 ( PDF , 8,278 kB).
- ↑ a b Michael R. Gannon, Michael R. Willig and J. Knox Jones, Jr .: Morphometric Variation, Measurement Error, and Fluctuating Asymmetry in the Red Fig-eating bat (Stenoderma rufum) . In: The Texas Journal of Science . No. 4 , 1992, pp. 391-404 .
- ↑ a b Stenoderma rufum in the IUCN Red List of Endangered Species . Posted by: A. Rodriguez, L. Dávalos, 2008. Retrieved February 10, 2010.
- ^ Rosser W. Garrison and Michael R. Willig .: Arboreal Arachnids . Appendix 6 - Foraging Status of Invertebrates in the El Verde Rain Forrest. In: Douglas P. Reagan and Robert B. Waide (Eds.): The Food Web of a Tropical Rain Forest . The University of Chicago Press, Chicago 1996, ISBN 0-226-70600-1 , pp. 117 ff .