Guadeloupe big-eyed bat
|Guadeloupe big-eyed bat|
R.J Baker & Genoways, 1976
The Guadeloupe big-eyed bat (Chiroderma improvisum) is a species of bat in the family Phyllostomidae. It is found in Guadeloupe and Montserrat. It is threatened by habitat loss mostly because of Hurricane Hugo, which destroyed 90% of the population of this bat in 1989. The species may be locally extinct in some areas of Guadeloupe.
Taxonomy and etymology
The Guadeloupe big-eyed bat was described in 1976. The holotype was collected in July 1974 in Baie-Mahault commune of Basse-Terre Island. Its species name is of Latin origin and means "unforeseen" or "unexpected." Baker and Genoways chose this species name because they "did not expect to find Chiroderma on Guadeloupe because the nearest known representative from the Caribbean occurs on Trinidad and Tobago, 550 kilometers to the south."
Baker and Genoways, when initially describing the species, speculated that it might be closely related to the Brazilian big-eyed bat, and that the current two species were relicts of a single, once-widespread species. Conversely, in the same paper, they conceded that the two species may be similar to each other only through convergent evolution. However, in a 1994 study, Baker and others examined the mitochondrial DNA of the big-eyed bats and found that it is actually most closely related to the hairy big-eyed bat, which is its sister taxa. The Guadelouope big-eyed bat and the hairy big-eyed bat diverged from the Brazilian big-eyed bat and the little big-eyed bat around 2.6 million years ago. The Guadeloupe big-eyed bat then diverged from the hairy big-eyed bat 2.1 million years ago.
It is the largest member of its genus, Chiroderma. Its body length is 85–88 mm (3.3–3.5 in). Its forearm is 57.5 mm (2.26 in) long. Its nose-leaf is approximately 5.9 mm (0.23 in) long. Its hind foot is 15–17 mm (0.59–0.67 in) long, and its ear is 21–21.5 mm (0.83–0.85 in) long. Its fur has a woolly texture. Individual hairs are 10 mm (0.39 in) long on its back. Its hairs are mostly a pale brownish-gray; the bases of the hairs are darker, while the tips are a rich, dark brown. Some individuals have a distinct white stripe down their backs. In some individuals, the coloration of individual hairs is distinctly tricolored. Fur on its belly is grayish-brown, with individual hairs tipped in white.
It is a diploid species, with 26 chromosomes. Its fundamental number is 48. It is frugivorous. Little is known about its reproduction. A lactating female was once encountered in July. It is known to be parasitized by mites of the family Spinturnicidae (Periglischrus iheringi). This mite species is a common ectoparasite of leaf-nosed bats.
Range and habitat
It has been documented on the islands of Guadeloupe and Montserrat, both of which are part of the Lesser Antilles of the Caribbean Sea. In 2016, it was documented for the first time on Saint Kitts Island, which is also part of the Lesser Antilles. This discovery expanded the known range of the species by 80 km (50 mi).
It is currently evaluated as endangered by the IUCN. The 2016 listing as endangered was an uplisting from its 2008 listing as vulnerable. It meets the criteria to be listed as endangered because it is known from fewer than five locations, its extent of occurrence is approximately 4,000 km2 (1,500 sq mi), its area of occupancy is 1,000 km2 (390 sq mi), and there is an ongoing decline in the extent and quality of its habitat. In 2008, individuals of this species were captured in Montserrat, alleviating fears that it had gone extinct. Before this individual was captured, the last Guadeloupe big-eyed bat documented on Montserrat was in 1984. It is thought that the bat species of Montserrat could be threatened by dramatic natural events, such as hurricanes and volcanic eruptions.
- Solari, S. (2016). "Chiroderma improvisum". IUCN Red List of Threatened Species. IUCN. 2016: e.T4665A22037238. Retrieved 23 July 2016.
- Baker, R. J.; Genoways, H. H. (1976). "A new species of Chiroderma from Guadeloupe, West Indies (Chiroptera: Phyllostomidae)". Mammalogy Papers: University of Nebraska State Museum. 186 (39). Retrieved October 12, 2017.
- Jones, J. Knox; Baker, Robert J. (1980). "Chiroderma improvisum" (PDF). Mammalian Species. 134. doi:10.2307/3504068. Retrieved October 11, 2017.
- Baker, R. J.; Taddei, V. A.; Hudgeons, J. L.; Van Den Bussche, R. A. (1994). "Systematic relationships within Chiroderma (Chiroptera: Phyllostomidae) based on cytochrome b sequence variation". Journal of Mammalogy. 75 (2): 321–327. doi:10.2307/1382550. JSTOR 1382550.
- Pedersen, S. C.; Kwiecinski, G. G.; Larsen, P. A.; Morton, M. N.; Adams, R. A.; Genoways, H. H.; Swier, V. J. (2009). "Bats of Montserrat: population fluctuation and response to hurricanes and volcanoes, 1978–2005". In Fleming, Theodore H.; Racey, Paul A. (eds.). Island bats: evolution, ecology, and conservation. University of Chicago Press. pp. 302–340. Retrieved October 12, 2017.
- Larsen, R. J.; Boegler, K. A.; Genoways, H. H.; Masefield, W. P.; Kirsch, R. A.; Pedersen, S. C. (2007). "Mist netting bias, species accumulation curves, and the rediscovery of two bats on Montserrat (Lesser Antilles)". Acta Chiropterologica. 9 (2): 423–435. doi:10.3161/1733-5329(2007)9[423:mnbsac]2.0.co;2. Retrieved October 12, 2017.
- Beck, J. D.; Loftis, A. D.; Daly, J. L.; Reeves, W. K.; Orlova, M. V. (2016). "First record of Chiroderma improvisum Baker & Genoways, 1976 (Chiroptera: Phyllostomidae) from Saint Kitts, Lesser Antilles". Check List. 12 (2): 1854. doi:10.15560/12.2.1854. Retrieved October 12, 2017.
- Young, R. P. (2008). "Topic 9: Species recovery including captive breeding". A biodiversity assessment of the Centre Hills, Montserrat (PDF) (Report). Durrell conservation monograph. 1. Durrell Wildlife Conservation Trust. pp. 323–324. Retrieved October 12, 2017.