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 its population in 1989. The species may be locally extinct in some areas of Guadeloupe.
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.[2] 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.[4]
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). 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.[3]
Some individuals have a distinct white stripe down their backs.[2] In some individuals, the coloration of individual hairs is distinctly tricolored. Fur on its belly is grayish-brown, with individual hairs tipped in white.[3]
It has been documented on the islands of Guadeloupe and Montserrat, both of which are part of the Lesser Antilles of the Caribbean Sea.[3] 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).[7]
It is currently evaluated as endangered by the IUCN. The 2016 listing as endangered was an uplisting from its 2008 listing as vulnerable.[1] In 2008, individuals of this species were captured in Montserrat, alleviating fears that it had gone extinct.[8] 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.[5]
^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. JSTOR1382550.
^ abPedersen, 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.
^Young, R. P. (2008). "Topic 9: Species recovery including captive breeding"(PDF). A biodiversity assessment of the Centre Hills, Montserrat (Report). Durrell conservation monograph. Vol. 1. Durrell Wildlife Conservation Trust. pp. 323–324. Retrieved October 12, 2017.
