A small bat with large ears that roosts in and around the Point Reyes National Seashore could get some added protection.
Presently the Townsend's big-eared bat is listed as a "species of special concern" by the state Department of Fish and Wildlife. That same agency is now being asked to increase the level of protection to "endangered" or "threatened."
"We find them here in old barns and under bridges," said John Dell'Osso, chief of interpretation at Point Reyes. "We also find them in tree hollows. In the springtime we have maternal roost colonies. It's an interesting species, and they have those large ears."
While their bodies average about 4 inches in length, their ears grow to 1.5 inches. Those large ears make it easier to hear predators and they are believed to provide lift during flight and assist with temperature regulation. The bats leave roosts as the sun goes down, feeding on mosquitoes, moths and other insects.
Human activity resulting in the loss of roost sites during the maternity and hibernation seasons are considered the primary factors that have hurt the species in California, although disease, climate change, pesticide use and other factors may also play a role, according to the National Park Service.
It is believed before humans came to the state, tree hollows were a primary source of habitat. But when forests were logged for wood to build homes, huge swaths of habitat were lost. The bats were able to adapt and began using old buildings and abandoned mines, but as they are taken down or sealed up, they are lost as habitat too.
The species does fairly well in Marin.
"They are seen in large, old growth redwoods trees and Marin has those," said Scott Osborn, wildlife biologist with fish and wildlife. "The coast in Marin is fairly well protected and that helps these bats."
But in other parts of the state they are not faring as well. In November, the Center for Biological Diversity submitted a petition to the California Fish and Game Commission to formally list the bat as a threatened or endangered species. During the next year the department will conduct a status review on whether to list the species.
The Townsend's big-eared bat occurs throughout the west and is distributed from the southern portion of British Columbia south along the Pacific coast to central Mexico and east into the Great Plains, with isolated populations occurring in the central and eastern United States, according to the park service.
The bats live to about 16 years old, but can survive up to 30 years. The maternity colonies form between March and June, with pups born between May and July. Female bats usually only have one young a year. There is a strong maternal bond and the young bats squawk when the mother is away, which can be heard near roost sites.
Contact Mark Prado via email at email@example.com
©2014 The Marin Independent Journal (Novato, Calif.)
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