Bats---the only mammals capable of true flight-date back more than 50 million years and are among the most misunderstood and most unfairly maligned mammals in the United States. Contrary to popular belief, they do not attack humans. And because insectivorous bats consume vast numbers of insects, and are the primary pollinators of a wide range of plants-particularly in the Arizona and Texas deserts-they also rank among the most beneficial. Bats are the only major predators of night-flying insects; a single bat can eat between 600 and 1,200 mosquitoes in an hour.

In addition to mosquitoes, many bats prey upon agricultural pests like corn borers, grain and cutworm moths, potato beetles and grasshoppers. And bat droppings, or "guano," support ecosystems of bacterial organisms that can be used to detoxify wastes and manufacture antibiotics.


Mariana fruit bats are found in Guam and the Commonwealth of Northern Mariana Islands, and move from island to island. In northern Guam, bats forage and roost mostly in native "limestone" forest, a local forest type characterized by limestone terraces and volcanic soils. Fruit bat colonies sleep during the day, but perform other activities diurnally as well-grooming, breeding, scent-rubbing, marking, flying, climbing to other roost spots, and, in the case of so-called "harem males," defending roosting territories.

Guam's Mariana and Little Mariana fruit bats are threatened by a variety of federal actions, including military training exercises; the clearing and fragmentation of forest habitat for roads, warehouses and other construction projects; and the building of resorts, golf courses, and other recreational facilities.


In April 2000, the Center for Biological Diversity, along with the Marianas Audubon Society, sued the U.S. Fish and Wildlife Service for failing to designate critical habitat, as required under the Endangered Species Act, for seven endangered species from Guam, including the Little Mariana fruit bat. We are preparing follow-up actions.

The lesser long-nosed bat was originally listed as endangered in 1988. No critical habitat has been designated for the species, and the recovery plan was not completed untill 1997. In August 1998, the Center filed suit against Coronado National Forest for harming endangered species including the bat on 47 livestock grazing allotments by permitting 10,000 cattle on over 430,000 acres. The Forest continues to allow the livestock industry to run cattle on these allotments to the detriment of the lesser long-nosed bat.

graphic Andrew Rodman ©2002
July 3, 2003
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