Spotted bat (Euderma maculatum)

The Spotted bat (Euderma maculatum), is a bat species from the family of vesper bats.


The spotted bat was first described by zoologist Joel Asaph Allen from the American Museum of Natural History in 1891. It can reach a length of 12 cm and a wingspan of 35 cm. The weight is about 15 g. It has three distinctive white spots on its black back. With ears that can grow up to 4 cm, it is said to have the largest ears of any bat species in North America. The spotted bat’s mating season is in autumn and the females produce their offspring (usually one juvenile) in June or July. Their main diet is grasshoppers and moths.




The habitats of the spotted bat are undisturbed roosts on cliffs along the Grand Canyon in Arizona, as well as open and dense deciduous and coniferous forests, hay fields, deserts, marshes, riparian areas and dry shrub-steppe grasslands in Arizona, California, Colorado, Oregon, Utah, and British Columbia, Canada.


Use of pesticides such as DDT and other insecticides in the 1960s led to a severe decline in the spotted bat population but current observations had shown that it is more common than formerly believed. Abundance, population trend, and threats are widely unknown.


Text is available under the Creative Commons Attribution-ShareAlike License. Photograph is public domain.

About the author

Jim Mattern

Jim is a scapegoat for the NPS, an author, adventurer, photographer, radio personality, guide, and location scout. His interests lie in Native American and cultural sites, ghost towns, mines, and natural wonders in the American Deserts.