Artificial 'Cave' Habitat on Bridges to Benefit Sensitive Bats

Focus Area

Wildlife & Ecosystems


Natural Resources






2-3 years

Research Idea Scope

The benefits of bats to humans and the environment are well known. Some are principal pollinators and others consume large quantities of insects detrimental to agricultural crops and human health. Nearly 40% of American bat species are threatened or endangered, and since 2006, more than one-million insect eating bats have died from White Nose Syndrome (WNS). The species most susceptible to WNS are cave hibernating bats. Box-beam bridges frequently are used by cave-dwelling bats, but when these bridges are replaced, they often are not replaced with other box-beam bridges. This removes suitable bat habitat for species already in trouble. The proposed research would explore the feasibility of incorporating artifical cave habitat into bridges, i.e., removable box-like structures that do not contribute to the structural integrity of the bridge. Some state DOTs have already experimented with artifical bat caves on bridges and it would be beneficial to consolidate the information, analyze their use by bats, and propose standard designs and suitable locations for placement on bridges.

Urgency and Payoff

There is significant concern about the lethal effects of WNS on bats and the speed at which this infection is making its way across the United States. Some predict major biological and economic impacts as bat populations crash. DOTs are in an unique position to assist fragile bat populations by incorporating bat habitat (i.e., artificial caves) into bridge designs. By designing bat habitat into bridges, not only are we providing bat refugia, but we can direct bats to bridge areas that will not conflict with operational or maintenance actions.

Suggested By

Chris Maguire ODOT 503-831-3665

[email protected]