Guadeloupean big-eyed bat  (Chiroderma improvisum)

The Guadeloupean big-eyed bat is classified as Vulnerable (VU) on the IUCN Red List (1).

The Guadeloupean big-eyed bat (Chiroderma improvisum) is the largest of the six species in the genus Chiroderma (2). Although this species was previously known as the Antillean white-lined bat, the bats in this genus are now known as the ‘big-eyed bats’, due to their unusually large eyes.

The Guadeloupean big-eyed bat has rich, dark brown ‘woolly’ fur with a hint of grey. Distinctive white lines run down the lower half of its back, as well as above and below the eyes (2).

The Latin name of the Guadeloupean big-eyed bat, improvisum, means ‘unexpected’ or ‘unforseen’, as when this species was discovered, its nearest known relative from the Caribbean was found on Trinidad and Tobago, over 550 kilometres away (2).

The Guadeloupean big-eyed bat is found in both Guadeloupe and Montserrat, in the Lesser Antilles (1).

Little is know about the habitat of the Guadeloupean big-eyed bat; however, in the past it has been collected in open fields next to gallery forest, and over streams (3).

Being a rare species (1), knowledge of the biology of the Guadeloupean big-eyed bat is limited, and despite ongoing surveys, no specimens were found between 1985 and 2004. However, a lactating female was caught and released during July on the island of Montserrat in 2005 (4).

Bats of the New World tropics typically give birth twice a year, at times when food is plentiful. The Guadeloupean big-eyed bat is thought to give birth to a single infant at a time, with the female mating again shortly after the birth. Young bats are unable to fly during the first few weeks of life, and so are particularly vulnerable at this time (5).

Little is known about the diet of the Guadeloupean big-eyed bat, but it is presumed to feed mainly upon fruit, like other species in the genus Chiroderma (2). Frugivorous bats play an important role in seed dispersal, which is particularly important on the island of Montserrat, where volcanic eruptions, and Hurricane Hugo in 1989, have led to the defoliation of much of the island (6).

Unfortunately, it seems that habitat degradation may have caused a massive decline in the population of the Guadeloupean big-eyed bat, as researchers have reported a 20-fold decrease in capture success since the most recent natural disasters took place in the region (6).

The Guadeloupean big-eyed bat faces ongoing threats from habitat conversion, extreme weather events such as hurricanes and flooding, and the risk of volcanic eruption on Montserrat (1).

There are currently no known specific conservation measures in place for the Guadeloupean big-eyed bat. However, Bat Conservation International, an organisation that works throughout the Caribbean and Latin America, where 30 percent of the world’s documented bat species reside, is working to protect bat populations through conservation, education and research initiatives (7).

More information on the conservation of bats:

• Bat Conservation International:
  http://batcon.org/
• The IUCN/SSC Bat Specialist Group:
  http://www.batconservancy.org/chiroptera-specialist-group-bat-conservation.php

Find out more about conservation on Montserrat:

• UK Overseas Territories Conservation Forum - Montserrat:
  http://www.ukotcf.org/territories/montserrat.htm